Cap banks - the pre-emptive answer

[drwayne]

Here's the answer before you ask.


external cap banks ADD capacitance to your ESC.

When adding a cap bank, DO NOT remove existing esc caps ( replace dead ones with new ones, sure.. rated same )

Just delivered my desk... a new HV ESC where the owner had removed all onboard caps and replaced with an external cap bank.

I know this fellow had the best intentions, so there will be no finger pointing and gesticulating (look it up) for all to see.

83341

[tlandauer]

Question: I plan to add cap bank to Seaking 180 ESC, I bought this one: http://www.offshoreelectrics.com/proddetail.php?prod=etti-e041&cat=136. The recommended installation is to open up/strip the power wire near the base board and solder the + and - notches onto the wire. That will be difficult in my case, can I open up the power wires at the same location but instead solder two short ( very short , no more than 30 mm) wires and then attach them to the + and - notches on the cap bank?

[drwayne]

Question: I plan to add cap bank to Seaking 180 ESC, I bought this one: http://www.offshoreelectrics.com/pro...i-e041&cat=136. The recommended installation is to open up/strip the power wire near the base board and solder the + and - notches onto the wire. That will be difficult in my case, can I open up the power wires at the same location but instead solder two short ( very short , no more than 30 mm) wires and then attach them to the + and - notches on the cap bank?

It is far more electrically efficient to mount the caps further away on the power wires than using a branch


This is NOT how you do it 83340


The T180 wires are long enough to allow the capbank mounted further away from the esc.

[tlandauer]

Thank you very much, that is good to know. My problem is not entirely the length of the wires but rather I have no over head clearance fron the hull, I need the bank to be on the outside of the original caps, the wires now go over the heat sink to the batteries, there is no room above the heat sink. So my only solution is to wire-out the cap bank. It is infact like the T180 V3---how the maker does, two wires to the + and - terminal. But I don't want to over heat the terminal, so was thinking splicing /joining the power wire with the cap bank.
Sorry to be so long winded!
Cheers!

[tlandauer]

Thank you again for the addition of the pictures , I really appreciate you spending your time here!

[tlandauer]

[QUOTE=drwayne;447888]It is far more electrically efficient to mount the caps further away on the power wires than using a branch

I understand, maybe i need to rethink my solution, efficiency is important.
Thanks!

[drwayne]

Question: I plan to add cap bank to Seaking 180 ESC, I bought this one: http://www.offshoreelectrics.com/proddetail.php?prod=etti-e041&cat=136. The recommended installation is to open up/strip the power wire near the base board and solder the + and - notches onto the wire. That will be difficult in my case, can I open up the power wires at the same location but instead solder two short ( very short , no more than 30 mm) wires and then attach them to the + and - notches on the cap bank?


[QUOTE=drwayne;447888]It is far more electrically efficient to mount the caps further away on the power wires than using a branch

I understand, maybe i need to rethink my solution, efficiency is important.
Thanks!

I run some very high demand setups, and the cap banks are anywhere between the Batts and ESC.. the closeness to esc is usually to limit the amount of extra plugs between the esc/capbank....

Here are 2 photos of 2 different setups for caps in 2 diff builds of same hull.
One has caps on back the SF240HV esc, other has a shared capbank that is attached direct too batts.. with leads out to the SF15S300A esc.

Both drove heavily loaded 5692 with no issues.

8334283343

[tlandauer]

You have cleared up alot of misconceptions that I have. Thank you from the bottom of my heart for spending all this time to post and take pictures!
Tim

[ray schrauwen]

Of course not, those caps are in series thereby halving the capacitance if they are same.
Did you mean something else?


It is far more electrically efficient to mount the caps further away on the power wires than using a branch


This is NOT how you do it 83340


The T180 wires are long enough to allow the capbank mounted further away from the esc.

[ray schrauwen]

I did not think that large wires are required for offboard cap banks as I am planning to use 14G wire 8" away from esc.

My reasoning: they are only dealing with AC ripple current not full DC load current.

What say you?

[tlandauer]

I am sure you are addressing to drwayne, but I agree with you, I have done another set-up using 14G wires few inches away from ESC. My misconception was that either the wires has to be very short or if you solder the cap bank on to the main power wires it has got to be close to the ESC.

[drwayne]

Of course not, those caps are in series thereby halving the capacitance if they are same.
Did you mean something else?

How else should I say it, Ray ?? "This is NOT how you do it "


I did not think that large wires are required for offboard cap banks as I am planning to use 14G wire 8" away from esc.

My reasoning: they are only dealing with AC ripple current not full DC load current.

What say you?

I said what ...Please quote { } where ... :smile:

Although, purely for the sake of discussion ... from a practicality angle, larger gauge wire decreases EMF, heating and resistance.... and are a heck of a lot easier to handle.
see attached for an example

Is that what you wanted me to say ?
If you mean the large gauge wires from both installed pics above, the middle bank is fed direct from the 12S batt packs ( black plug visible on left, red on right) .. and direct from that bank to the ESCs.. there are no 'patch' leads there.
The esc mounted cap banks in other pic, are large gauge because it offered more rigidity in the assembled units... sizes 14 upwards are okay IME

83356

83357

edit: these 2 pics are from ''Fabs" setup for his 4S OBT

[drwayne]

Here are some details of the shared bank

83358

83359

for 12S2P feeding 2x 300A esc - 5698/910 - X665 ... child's play ! ( big kids )

[Basstronics]

How do you get A/C ripple on the DC side? In a car I under stand how. In a boat we dont have an alternator generating ac thought...

I still fal to reason the need for large cap banks in these boats.

[ray schrauwen]

Thats what I was asking or trying to find out.

I'm sorry my posts were poorly written. I do that sometimes when I haven't eaten enough.

I didn't want you to "say" anything. My apologies sir. :unsure:

Of course if in-line I'd use heavy guage too but, I wanted mine off the side in flotation so it was out of the way. Since it's not carrying a high amp load as far as I know ??? I was hoping after seeing your posts that I was O.k. and didn't have to change it.

Thanks for your posts!



How else should I say it, Ray ?? "This is NOT how you do it "



I said what ...Please quote { } where ... :smile:

Although, purely for the sake of discussion ... from a practicality angle, larger gauge wire decreases EMF, heating and resistance.... and are a heck of a lot easier to handle.
see attached for an example

Is that what you wanted me to say ?
If you mean the large gauge wires from both installed pics above, the middle bank is fed direct from the 12S batt packs ( black plug visible on left, red on right) .. and direct from that bank to the ESCs.. there are no 'patch' leads there.
The esc mounted cap banks in other pic, are large gauge because it offered more rigidity in the assembled units sizes 14 upwards are okay IME 83356


83357

edit: these 2 pics are from ''Fabs" setup for his 4S OBT

[ray schrauwen]

Here's the answer before you ask.


external cap banks ADD capacitance to your ESC.

When adding a cap bank, DO NOT remove existing esc caps ( replace dead ones with new ones, sure.. rated same )

Just delivered my desk... a new HV ESC where the owner had removed all onboard caps and replaced with an external cap bank.

I know this fellow had the best intentions, so there will be no finger pointing and gesticulating (look it up) for all to see.

83341

Can I ask why is it bad to remove the old ones as pictured and run it as pictured? What happens? What will go wrong?

EDIT: That is if they have all gone bad, not if they were still good.

[turbonutt]

drwayne, where did you get the raw circuit board material?

[tlandauer]

Here in the States, Radio Shack sells them.

[drwayne]

Thats what I was asking or trying to find out.

I'm sorry my posts were poorly written. I do that sometimes when I haven't eaten enough.

I didn't want you to "say" anything. My apologies sir. :unsure:

Of course if in-line I'd use heavy guage too but, I wanted mine off the side in flotation so it was out of the way. Since it's not carrying a high amp load as far as I know ??? I was hoping after seeing your posts that I was O.k. and didn't have to change it.

Thanks for your posts!


If I miss food.sleep/medication I spend next morning apologizing for my last night's posts. :(

Im sure you know this.. capacitors are 'miniature super batteries' that charge and discharge super quick. YES, there is a lot of current/energy
flowing through the wire conduits.. so larger wire on long satellite leads is a must.. ( resistance, EMF, delta Tmp )
Ive evidenced caps under load where the flow is sufficient to burn their own leads away...
Id recommend to 'overcompensate' when adding cap banks.. a few $ more can be the saving grace for your setup.


Can I ask why is it bad to remove the old ones as pictured and run it as pictured? What happens? What will go wrong?

EDIT: That is if they have all gone bad, not if they were still good.

as pictured ?
In the first #1 post, that ESC was NEW ( or a few runs old only )... !
If the onboard caps die, Id most certainly add replacements inside or out.. the circuit was clearly stressed with those existing, so ADD MORE !

Remember this, capacitors store energy.
They are waiting to BITE you 'bad'.

W

[properchopper]

Doc, Is it possible or "not good" to have too many or too big a cap addition ? (my understanding of basic electronics stops at OUCH :ohmy:)

83375

[properchopper]

for giggles I searched "capacitor explosion" on youtube. Some crazy stuff there

http://www.youtube.com/watch?v=kjhoePUJ8Vg

[stractor]

Please excuse my interruption here, but aren't cap banks supposed to be made up of "X" of amount of caps arranged in parallel so the capacitance of the bank is equal to the sum of all the cap valves in microfarads? That is added c1+c2+c3 = total. I ask this question because in looking at several of the posted pictures some of the banks seem to be made up of sets of two caps in series and these sets are then wired in parallel. The caps set of two caps in series doesn't add but equals a value less than one of the caps value. In the example I am refering to putting two 1000uf caps in series will equal 500uf. See the following link http://www.calctool.org/CALC/eng/electronics/cap_series
If there is another reason for wiring them in a series and parallel configuration or I am missing something please tell me.

The following picture seem to illustrate what I am talking about. Of the small board pictures one is from underneath and seems to show three pairs of series caps in parallel . If you give a value of 1000uf to the six caps the total capacitance of the board is 3000uf or so and not 6000 as if they were all in parallel.
The larger board seems to show the same thing, but there is no picture of the underside showing the actual solder connections.
Of course I could be completely wrong in my thinking.

833768337783378

[keithbradley]

Here are some details of the shared bank

83358

83359

for 12S2P feeding 2x 300A esc - 5698/910 - X665 ... child's play ! ( big kids )

Have you happened to log that combo yet Wayne? I'm curious what kind of current you're pulling with that setup...

[drwayne]

On road atm. 1030am here in South Australia.
More when at desk

I deleted this because it confused even me !

[ray schrauwen]

Very interesting DrWayne.

[drwayne]

Words Vs pictures
remember these numbers ... ...
C= 470uf cap, low ESR, rated voltage ~ 25% above your pack voltage
2 in parallel c1+c2=940uf
2 in series offers C1xC2/(C1+C2) = 235uF !!!!!!
series (-)---[C1]---[C2]---(+)

That series pair in 3x parallel array offers 705uf
(-)---[C1]---[C2]---(+)
(-)---[C1]---[C2]---(+)
(-)---[C1]---[C2]---(+)

Initial charge of the 6 caps is same as if all were individually charged

OMG Ive written and rewritten this a few times and each time I start expanding on referenced detail that loses most people.

simply..
In this circuit, the charge/discharge speed is 8x the std , thus smoothing the DC line ripple more effectively ... even though the energy return availability is 705/2820 ( std6 caps ) .. it presents 8x speed of charge/return into of those original individual 6 caps.. gives us twice the total energy available, at a far higher return rate than std. ( 705 x 8 / 2820 )
In the 15S300A5698/910 example I used a total of 1410uF as detailed here, and logged ripple <0.19Vdc.
Unfiltered, ripple measured >1.6Vdc .. but I didnt enjoy the lacklustre performance so I went home...
I use cap banks as detailed to cover both yield(battery recharges the caps) and reply(esc demand on power system) needs of the system.
------
I read above .. What is DC ripple ? . When the esc fires a phase, it draws energy from the 'energy sump' .( DC batteries ).. this causes a sudden voltage drop evidenced by a blip on the voltage display of your oscilloscope.
Each 3 firings ( a rotation of the motor ) makes 3 tiny blips ..... eg at 30,000rpm there are 90,000(at least) tiny blips.. a ripple .. an induced frequency.....EMF inciting ESR .....
This ripple.. creates an AC that is not usable by the DC-AC inverter (ESC) thus the esc now sees lower voltage...V x Kv - zoomzoom
Capacitor banks reduce the size of that ripple, the esc sees higher nett voltage = more fun.

If the cap bank is too large, it will induce it's own ripple as it recharges.


Would I recommend this type of cap array if asked .. depends on your application.
Im sure to edit this once Ive seen it in a fullscreen.. and read it as a mini-novel.
W

[nata2run]

I guess what Doc is trying to say.... as he has explained it to me a 1000 times is... Because the internal resistance of a battery is much higher than a capacitor. It takes a much longer time to get the same amount of energy from a battery, and the timing is very important. In fact, using a different combination of capacitors/layout can give us the exact control we need. I guess the idea here is time/responce over high numbers of uf. It makes perfect sense..... I wouldnt recommend everyone to just play with caps in series (doc knows what he's doing) as it can have a reverse effect.

(my selective hearing and 10c worth)

[drwayne]

I guess what Doc is trying to say.... as he has explained it to me a 1000 times is... Because the internal resistance of a battery is much higher than a capacitor. It takes a much longer time to get the same amount of energy from a battery, and the timing is very important. In fact, using a different combination of capacitors/layout can give us the exact control we need. I guess the idea here is time/responce over high numbers of uf. It makes perfect sense..... I wouldnt recommend everyone to just play with caps in series (doc knows what he's doing) as it can have a reverse effect.

(my selective hearing and 10c worth)

Wow. here I was thinking you had learmomg difficulties :lol: :laugh:

[nata2run]

HA! yes, only 1000 times later LOL

[ray schrauwen]

Holy Cow! I didn't think it was that complicated!
YOu oviously make good sense from what I read.

I would guess the Etti cap bank is all parellel ? Since only 5 caps...?

Copy & paste in archives...

Thank you! :thumbup1:


Words Vs pictures
remember these numbers ... ...
C= 470uf cap, low ESR, rated voltage ~ 25% above your pack voltage
2 in parallel c1+c2=940uf
2 in series offers C1xC2/(C1+C2) = 235uF !!!!!!
series (-)---[C1]---[C2]---(+)

That series pair in 3x parallel array offers 705uf
(-)---[C1]---[C2]---(+)
(-)---[C1]---[C2]---(+)
(-)---[C1]---[C2]---(+)

Initial charge of the 6 caps is same as if all were individually charged

OMG Ive written and rewritten this a few times and each time I start expanding on referenced detail that loses most people.

simply..
In this circuit, the charge/discharge speed is 8x the std , thus smoothing the DC line ripple more effectively ... even though the energy return availability is 705/2820 ( std6 caps ) .. it presents 8x speed of charge/return into of those original individual 6 caps.. gives us twice the total energy available, at a far higher return rate than std. ( 705 x 8 / 2820 )
In the 15S300A5698/910 example I used a total of 1410uF as detailed here, and logged ripple <0.19Vdc.
Unfiltered, ripple measured >1.6Vdc .. but I didnt enjoy the lacklustre performance so I went home...
I use cap banks as detailed to cover both yield(battery recharges the caps) and reply(esc demand on power system) needs of the system.
------
I read above .. What is DC ripple ? . When the esc fires a phase, it draws energy from the 'energy sump' .( DC batteries ).. this causes a sudden voltage drop evidenced by a blip on the voltage display of your oscilloscope.
Each 3 firings ( a rotation of the motor ) makes 3 tiny blips ..... eg at 30,000rpm there are 90,000(at least) tiny blips.. a ripple .. an induced frequency.....EMF inciting ESR .....
This ripple.. creates an AC that is not usable by the DC-AC inverter (ESC) thus the esc now sees lower voltage...V x Kv - zoomzoom
Capacitor banks reduce the size of that ripple, the esc sees higher nett voltage = more fun.

If the cap bank is too large, it will induce it's own ripple as it recharges.


Would I recommend this type of cap array if asked .. depends on your application.
Im sure to edit this once Ive seen it in a fullscreen.. and read it as a mini-novel.
W

[drwayne]

Thanks Ray.
I apologize if my spiel was over the top .. the benefits can be lost if detail ignored, IME.
Yes, the 5xcap ETTI bank ( here at OSE) is parallel. Ideal for any application. If you have a high rpm ( +45k rpm) and/or use a high demand motor, the parallel cap banks are limited in energy turnaround ( still charging when esc demands more.. )
All this being said, many people have successfully run sets without the circuit in this post..
Flashbulb circuits are similar the established circuit for cap banks.. FLASH, then recharge... FLASH, then recharge.FLASH, recharge, and so on ..
The circuit detailed above would deliver a smaller Flash, but allows more frequent releases ( 8 fold ) equating a nett higher turnaround per second.

Ive been archived ? . wow, now Im preserved for eternity !

regs
W



Holy Cow! I didn't think it was that complicated!
YOu oviously make good sense from what I read.

I would guess the Etti cap bank is all parellel ? Since only 5 caps...?

Copy & paste in archives...

Thank you! :thumbup1:

[maxmekker]

Hello . This is starting to be beyond me technically at this point. I just want to ask a few quick questions from the start of the post. I’ll Try to keep it short
I wonder , how will a ESC performe if the caps are getting bad ?

I’m asking since My T180 ( 2+ years) is feeling a bit strange, like it's not 'opening up' I hit 100% throttle, and it feels like just 75% if you get me. (and yes I have re prog. It)
The caps looks fine, no bulging ore leak’s, but last year I did some 5s runs with my leo 4074 2000kv and the caps got really hot(x442 prop 45-90c lipos) so I thought about a cap bank, but never got around to get one before end of sess. Last year ( I did only a few packs of 5s, running on 4s most) . Well I have one now, the one ( ose cap bank) mentioned by tlandauer.

Anyway, the strange feel of the ESC I talked about came after I did some run with a new 4074 2150kv + 65-130c Lipo’s This year . I got some heat problem to (desolder of the + wire towards the ECS on the serial cabel 3 times)only with the 65-130c. But the heat on the caps/ecs motor were all fine.
But I thought about last years’s 5s runs and thought maybe the caps are saying goodbye.

If I boil it down the this:
How should I know if the caps are getting bad, and how should I hook up the ose cap bank , when stated in the first post not remove the existing cap’s. Did you get around doing you’re yet Tlandauer.

Thanks

[KartRacer]

Oh I get it. LOL. Not really or even maybe, but still very interesting reading. Thanks to all of the highly knowledgeable members on these threads. It DOES help!

[tlandauer]

Hello . This is starting to be beyond me technically at this point. I just want to ask a few quick questions from the start of the post. I’ll Try to keep it short
I wonder , how will a ESC performe if the caps are getting bad ?

I’m asking since My T180 ( 2+ years) is feeling a bit strange, like it's not 'opening up' I hit 100% throttle, and it feels like just 75% if you get me. (and yes I have re prog. It)
The caps looks fine, no bulging ore leak’s, but last year I did some 5s runs with my leo 4074 2000kv and the caps got really hot(x442 prop 45-90c lipos) so I thought about a cap bank, but never got around to get one before end of sess. Last year ( I did only a few packs of 5s, running on 4s most) . Well I have one now, the one ( ose cap bank) mentioned by tlandauer.

Anyway, the strange feel of the ESC I talked about came after I did some run with a new 4074 2150kv + 65-130c Lipo’s This year . I got some heat problem to (desolder of the + wire towards the ECS on the serial cabel 3 times)only with the 65-130c. But the heat on the caps/ecs motor were all fine.
But I thought about last years’s 5s runs and thought maybe the caps are saying goodbye.

If I boil it down the this:
How should I know if the caps are getting bad, and how should I hook up the ose cap bank , when stated in the first post not remove the existing cap’s. Did you get around doing you’re yet Tlandauer.

Thanks
In my case my caps were swelling, I knew it was time for me to replace the stock ones which was just what I did, the same found here: http://www.offshoreelectrics.com/proddetail.php?prod=ck-cap-35v-1000&cat=123
I took them out, my thread is found here : http://forums.offshoreelectrics.com/showthread.php?36619-Seaking-180A-ESC-CAPS-bulging!
I wanted to add a bank however, so I asked drwayne all those questions. Much to my regret, I don't have any room to attach the bank on the power wires, so I did what I could, it looks like your pictures. I must say for me to use this bank is over kill since my application is for 4s set up only. If I could fabricate a bank myself I would use the replacement caps, they are smaller. Here is a picture of what I did:83475
I think anytime you suspect the caps are not up to their job, replacing them is never a bad idea. However, while the bulged caps were still on the ESC, I did not see any degrading in performance, but swelling caps are time bombs so I replaced them immediately. I am not knowledgeable enough to tell you what if anything is wrong with your ESC, but if the caps are visually good, maybe something else needs to be considered.
By the way, if original caps are not in top shape, they NEED to be replaced, adding a bank over half-dead original ones is not a sound solution. What drwayne said was the seller removed ALL the original ones and just added a bank, if I understood correctly.

[ray schrauwen]

It has been a thought of mine for some time that why mosty Suppo esc's burn up is most likely due to faulty caps they buy in massive quantities not caring if they are way out of spec or just not made right at all. I mean, the fets on Suppos are a discontinued fet in USA that was shipped in container loads to China like many other obsoulete electronic components.

A while back I grabbed a near new HK SS100 esc and the cap wires nearly fell off from inside the caps?? I replaced the caps with blue 1000uF 35V-130* Rubycon RX30's right onto the board. It works very well now.

I remember Etti used to use the Suppo base board BUT, they used the blue Rubycon's instead.... wonder why.

[drwayne]

Hello . This is starting to be beyond me technically at this point. I just want to ask a few quick questions from the start of the post. I’ll Try to keep it short
I wonder , how will a ESC performe if the caps are getting bad ?

I’m asking since My T180 ( 2+ years) is feeling a bit strange, like it's not 'opening up' I hit 100% throttle, and it feels like just 75% if you get me. (and yes I have re prog. It)
The caps looks fine, no bulging ore leak’s, but last year I did some 5s runs with my leo 4074 2000kv and the caps got really hot(x442 prop 45-90c lipos) so I thought about a cap bank, but never got around to get one before end of sess. Last year ( I did only a few packs of 5s, running on 4s most) . Well I have one now, the one ( ose cap bank) mentioned by tlandauer.

Anyway, the strange feel of the ESC I talked about came after I did some run with a new 4074 2150kv + 65-130c Lipo’s This year . I got some heat problem to (desolder of the + wire towards the ECS on the serial cabel 3 times)only with the 65-130c. But the heat on the caps/ecs motor were all fine.
But I thought about last years’s 5s runs and thought maybe the caps are saying goodbye.

If I boil it down the this:
How should I know if the caps are getting bad, and how should I hook up the ose cap bank , when stated in the first post not remove the existing cap’s. Did you get around doing you’re yet Tlandauer.

Thanks

1. remove and replace all the onboard caps.
2. or, you can remove those onboard caps without replace, providing you add extra close by
3. Bad caps cause major draw from batteries = heat = melting things..
4. slow performance likely due those ld caps having a draw demand on batts, not feeding so much to esc.
5. caps do have a limited lifespan in high yield applications.. overheating them is terminal.

W.

[drwayne]

It has been a thought of mine for some time that why mosty Suppo esc's burn up is most likely due to faulty caps they buy in massive quantities not caring if they are way out of spec or just not made right at all. I mean, the fets on Suppos are a discontinued fet in USA that was shipped in container loads to China like many other obsoulete electronic components.

A while back I grabbed a near new HK SS100 esc and the cap wires nearly fell off from inside the caps?? I replaced the caps with blue 1000uF 35V-130* Rubycon RX30's right onto the board. It works very well now.

I remember Etti used to use the Suppo base board BUT, they used the blue Rubycon's instead.... wonder why.

+1
ditto CC240LV 3+ years back... use to burn cap leads ... 4S 1515/1Y - pop .. changed to upmarket caps.. 6S1527/1.5Y :smile:
around then decided to design own esc.... never looked back
W

[maxmekker]

Dr wayne and T landauer( do I see a Geico ? :-) ), thanks for the info.

I took out the t180 just now and snapped a few photos. Don't know if they have leaked ore if it's just becuase I did a poor job of drying it properly after I had a leak in the boat , but I will replace them.
So, just to make sure. Remove the 3 stock ones all together, and just solder the cap plate directly onto the T180, ore do I make a small gap with 8-10-12 G wires ?

I wonder if this will help on speed. It's like the boat have had a small amount of brake on the last times I have been out. I eveen felt slower with the 2150kv compared to the 2000kv I had in it before. Not that it has anything to do with caps (maybe) but here is a video of a pnp mystic I have set up for a friend, and my geico . We both run ose flex, T180 esc 45-90c lipo 642 prop and and the hull is the same so they should performe likewise. but the mystic smoked me. At firts he not floring it so be patient :-)


http://www.youtube.com/watch?v=-w-e5QNmJCM&list=UURNlga8sE0qJBcPb_5FFovQ&index=2&feature=plcp

[tlandauer]

You should first remove the old ones and solder replacement ones into the old holes so to speak. Take a look at the polarity before you do this, the trick is to have a helper firmly hold your ESC because you need to pull those with one hand while the other still holding the solder iron tip to heat the cap wires. On each of the cap I pull on polarity wire at a time, ---Don't over heat electronics. ( realistically you can't heat both + & - at the same time. yes, there is some twisting and yanking).
I shortened my Batt. to ESC wires prior to attaching the Cap Bank, therefore I deprived myself the chance of having enough wire INFRONT OF the ESC for directly mounting the Cap Bank. The hull of the Geico, yes it is MG!! is too shallow. I then had to add short pieces of wires between the Cap Bank and the ESC. Solder the wires under the main posts of the ESC---scrape the factory coating off first or you will have a hard time for the new solder to form a good contact.
Your third picture is exactly what I did, bridging the two with short 14g wires. But, if you can attach the Cap Bank on the main wires as drwayne recommands, it will be more efficient.
I used 14g wire only because I did not want to over heat the underside of the ESC main terminal, larger gauge wire is better, but if you look at the T-180 V3, their factory Cap bank is attached with very THIN wire, therefore I think 14g is enough.

[maxmekker]

I'll be on it soon, thanks. Pic's later.

[properchopper]

Amigo's,

I appreciate all the info and discussion on this important subject, but frankly I'm somewhat embarrased to admit that I can't readily distill the information offered into a simple, practical application realm. Is there a formula or application chart that would summarize how to choose/add capacitors for any given application given parameters that include battery voltage, esc capacity, motor pole/rpm considerations ? This might have been discussed before, but here might be a good time for a refesher course. In my honor it could be called "Capacitor Education for Electrically Challanged Dummies" :sad:

[tlandauer]

I don't think your slowing down has anything to do with the caps. Internal resistance as the contact gets unsoldered? Anyway, good video, enjoyed watching it. Also I realized you are an soldering expert so please do not take my long winded:blah: too seriously!:roflol:

[maxmekker]

Well I have made a tread about the unsoldering stuff, and got so my ears hung down for my poor a.. soldering job. I have been soldering for ages, some 200 playstation chips, loads of para/serial connections, lipo packs etc for my boat's and flying buddy's, but all of a sudden my serial cabel wich I had used for a long time came unsoldered. Then I made another one with higher G wire, all fine on 45-90c lipo, and then on 65-130c unsolder again, and the boat feels slow so I'm willing to try everything to see if it helps.

[maxmekker]

Anybody care to tell me what these little buggers do. One of them was 'eaten' on a bit, and was loose. No way I'm getting it to stick to the board again. So is it a rip on this 180 ?

[millzee]

I'm sure it'll be fine doc, As discussed on the phone, this speedo being made an example of had two caps that swelled a little on my very first day driving an fe boat. The DF35 (bomber boat) was my first boat, first build and first time driving a fe boat and as seen on the video made of my first ever run, the flex shaft was offline a tad causing vibrations and rubbing, add to the fact I'd never heard one of these boats so I didn't know the difference and drove it till the shaft went BANG. After retreiving the boat I took more video footage of the esc and caps and on advice removed the caps from the board and replaced them with the etti cap bank. This speedo has been this way for every run and video made of my df35, being my first boat and trying to learn how to trim, I had someone take video footage everytime I ran the boat, here's the Running history of the esc
first run: http://www.youtube.com/watch?v=tK0ITqCORmQ
2nd test: http://www.youtube.com/watch?v=6C-o7MV5Ifk
http://www.youtube.com/watch?v=yfVDJW6UXCs
http://www.youtube.com/watch?v=fA2uhwQpjzI
http://www.youtube.com/watch?v=U_hjJX8lqZM
http://www.youtube.com/watch?v=k3vG0-_GcqA
http://www.youtube.com/watch?v=nNXsKogxces

The boat was stripped down and became the bomber boat and never driven again due to the expensive graffiti put on the boat on Febuary 6th. I pulled the electronics back out and put the boat in a custom glass/mirror case, this being said, I'm sure the speedo is fine.

[Mike Caruso]

Words Vs pictures
remember these numbers ... ...
C= 470uf cap, low ESR, rated voltage ~ 25% above your pack voltage
2 in parallel c1+c2=940uf
2 in series offers C1xC2/(C1+C2) = 235uF !!!!!!
series (-)---[C1]---[C2]---(+)

That series pair in 3x parallel array offers 705uf
(-)---[C1]---[C2]---(+)
(-)---[C1]---[C2]---(+)
(-)---[C1]---[C2]---(+)

Initial charge of the 6 caps is same as if all were individually charged

OMG Ive written and rewritten this a few times and each time I start expanding on referenced detail that loses most people.

simply..
In this circuit, the charge/discharge speed is 8x the std , thus smoothing the DC line ripple more effectively ... even though the energy return availability is 705/2820 ( std6 caps ) .. it presents 8x speed of charge/return into of those original individual 6 caps.. gives us twice the total energy available, at a far higher return rate than std. ( 705 x 8 / 2820 )
In the 15S300A5698/910 example I used a total of 1410uF as detailed here, and logged ripple <0.19Vdc.
Unfiltered, ripple measured >1.6Vdc .. but I didnt enjoy the lacklustre performance so I went home...
I use cap banks as detailed to cover both yield(battery recharges the caps) and reply(esc demand on power system) needs of the system.
------
I read above .. What is DC ripple ? . When the esc fires a phase, it draws energy from the 'energy sump' .( DC batteries ).. this causes a sudden voltage drop evidenced by a blip on the voltage display of your oscilloscope.
Each 3 firings ( a rotation of the motor ) makes 3 tiny blips ..... eg at 30,000rpm there are 90,000(at least) tiny blips.. a ripple .. an induced frequency.....EMF inciting ESR .....
This ripple.. creates an AC that is not usable by the DC-AC inverter (ESC) thus the esc now sees lower voltage...V x Kv - zoomzoom
Capacitor banks reduce the size of that ripple, the esc sees higher nett voltage = more fun.

If the cap bank is too large, it will induce it's own ripple as it recharges.


Would I recommend this type of cap array if asked .. depends on your application.
Im sure to edit this once Ive seen it in a fullscreen.. and read it as a mini-novel.
W

For one I would like to thank you because I love to learn! Now at 63 years old I REALLY want to run over 100 MPH more than just once. HA Mike

[drwayne]

Well I have made a tread about the unsoldering stuff, and got so my ears hung down for my poor a.. soldering job. I have been soldering for ages, some 200 playstation chips, loads of para/serial connections, lipo packs etc for my boat's and flying buddy's, but all of a sudden my serial cabel wich I had used for a long time came unsoldered. Then I made another one with higher G wire, all fine on 45-90c lipo, and then on 65-130c unsolder again, and the boat feels slow so I'm willing to try everything to see if it helps.
How looooooooooooooooooooong are your leads ?

Anybody care to tell me what these little buggers do. One of them was 'eaten' on a bit, and was loose. No way I'm getting it to stick to the board again. So is it a rip on this 180 ?

Take a close up of the top,and show what details are embossed.
W.

[drwayne]

For one I would like to thank you because I love to learn! Now at 63 years old I REALLY want to run over 100 MPH more than just once. HA Mike

You're most welcome.
Run over 100mph ?.. I just wanna walk fast ..but that's a 2 bourbon story.

[maxmekker]

'How looooooooooooooooooooong are your leads ?'


hehe, I have both (now) while I did some new ones I did both a short and a longer one. I'll make a super short one and flip the lipos the other way with the wires comming out closer to the ESC.

Question, again, how about making the serial like it is on the stock esc that comes with the proboat mystic/geico.. Will it mess up the cell count( I don't use auto) you think , since it's a bit hard to plug both lipos at once if I make the serial on the ESC. Go bullet you say. Well I like the safety having a serial cabel made.

83536



'Take a close up of the top,and show what details are embossed.'



Will make a zoom pic when back from work. But it has a grove into it where there should be a tiny solder point.

[drwayne]

'How looooooooooooooooooooong are your leads ?'
83536
.

Yukko
Dean's connectors ( and clones ) are best suited under 4S 80A.. they gain resistance under high load ( they heat up quickly )

Your series connectir great.. for a low draw setup.
try something like this attached for shorter total lead length. fewer plugs.. and use 5.5mm plugs for higher Tx with lower dTemp.

Waiting for your pic !
W

83537

[maxmekker]

I use ec5 on all. I use deans in my 1/16 tanks only :-)

I have looked at the bullet type connection you have a draving off there, I'm afraid it will blow up on me when I mess it up ( it will happend :-)
my system is t180 leo 4074 2000/2150kv 4s 45-90c / 65-130c ,640, 642 m445 props. Should be in the safe zoone.

pics later man, thanks for helping out beond the tread issue

[drwayne]

I use ec5 on all. I use deans in my 1/16 tanks only :-)

I have looked at the bullet type connection you have a draving off there, I'm afraid it will blow up on me when I mess it up ( it will happend :-)
my system is t180 leo 4074 2000/2150kv 4s 45-90c / 65-130c ,640, 642 m445 props. Should be in the safe zoone.

pics later man, thanks for helping out beond the tread issue

If you cannot solder 5.5mm bullets, your friends are correct about your soldering technique ! :lol:
If you're worries about plugging it together wrong. pay attention!
and ..
batteries ...
female5.5 on battery positive
male5.5 on negative.

esc
positive is male5.5
negative 5.5female

whatever number of series cells you use.. they will all 'daisy chain' together to feed your esc.
Just be wary that last inline connection .. ZAP!

It's good keeping some topical posts on this thread.. keeps it at top !
and some others may gain help from the info.
W

[maxmekker]

If you cannot solder 5.5mm bullets, your friends are correct about your soldering technique !

are you mokking me ? hehe :-) I can solder bullets. it's what you say next, '' If you're worries about plugging it together wrong. pay attention!''

I know how it's done, it's just bullet proof with serial, and the system I have is not like a SAW boat so it should be ok. Maybe in the winter month's here in Norway I will sit down and convert over to bullets.

[drwayne]

My daughter wants permission to write an educational mockumentary about this thread's participants ... :lol:


If you cannot solder 5.5mm bullets, your friends are correct about your soldering technique !

are you mokking me ? hehe :-) I can solder bullets. it's what you say next, '' If you're worries about plugging it together wrong. pay attention!''

I know how it's done, it's just bullet proof with serial, and the system I have is not like a SAW boat so it should be ok. Maybe in the winter month's here in Norway I will sit down and convert over to bullets.

[maxmekker]

Here you go doc.

[tlandauer]

I know how it's done, it's just bullet proof with serial, and the system I have is not like a SAW boat so it should be ok. Maybe in the winter month's here in Norway I will sit down and convert over to bullets.[/QUOTE]
You should "bullet proof with bullets":roflol: drwayne is right, I made the change and never looked back. When I connect, I make sure my ex-wife is not around so my mind is in sound condition.
By the way, that thing fell from you ESC, the close up picures look like it fell from outter space. I too want to know what is it. I am learning alot from this post!

[Steven Vaccaro]

great thread! Thanks Doc!

[drwayne]

Here you go doc.

That's rooted, mate !
hahaha
I hope someone with a T180 can supply us with the details as embossed on their undead Surface mount capacitors .... ??

That being said.. a 47pf ceramic cap would do nicely as an alternative.. ensure the existing remnant(s) are removed before you add new.




great thread! Thanks Doc!

Very pleased to spoon feed information to an appreciative audience, Steven.

0¿0

W

[egneg]

That's rooted, mate !
hahaha
I hope someone with a T180 can supply us with the details as embossed on their undead Surface mount capacitors .... ??

That being said.. a 47pf ceramic cap would do nicely as an alternative.. ensure the existing remnant(s) are removed before you add new.





Very pleased to spoon feed information to an appreciative audience, Steven.

0¿0

W

Nothing visible Doc.

[properchopper]

That's rooted, mate !
hahaha
I hope someone with a T180 can supply us with the details as embossed on their undead Surface mount capacitors .... ?? That being said.. a 47pf ceramic cap would do nicely as an alternative.. ensure the existing remnant(s) are removed before you add new.





Very pleased to spoon feed information to an appreciative audience, Steven.

0¿0

W

This is an early (non "additional cap board equipped) T-180


83549

[maxmekker]

OK, so one of these would be ok to replace the broken one ?

83551

Do they go on one way ore another ore is it same same ?

Now to find one localy

[graill]

That's rooted, mate !
hahaha
I hope someone with a T180 can supply us with the details as embossed on their undead Surface mount capacitors .... ??

That being said.. a 47pf ceramic cap would do nicely as an alternative.. ensure the existing remnant(s) are removed before you add new.





Very pleased to spoon feed information to an appreciative audience, Steven.

0¿0

W

Great thread Wayne. A side note on the ceramic caps. I did alot of testing a year and change back, a few observations with some input from Rubicon.

Ceramic, or solid caps last only 1/3rd the life of the newer film variety for our applications, high voltage, fast discharge. Not good for ceramic type caps.
When they "burn out" they turn to powder inside or simply dead short and do not explode or bulge as the fluid/film do most times. When you lose one you will have to test your bank to find it the majority of the time.
They DO NOT have the same high performance at high discharge that film does, at lower constant voltage apps, computer mobos, power supplies, tv, stereos, they rule over film caps.
To match the performance of a film cap the engineer said the solid caps would need to be much larger verse a film cap. The next question was what is the comparison for our applications, he said there is none. The two types could have close to the same numbers but in our applications the solids will always fail first.
DO NOT mix solid and film caps, even if specs are the same (which would be rare).

I spoke with an engineer at Rubicon least year and change ago and to get a ceramic/solid cap working like the film caps out currently would be cost prohibitive, pennies on the dollar to test and manufacture for the regular types compared to 9-25 bucks per cap to meet our applications.

**Rubicon Engineer** "Why do you guys do that anyway?" Reference FE boating.

[stractor]

Surface mounted caps are available from some of the larger online sellers such as jamesco. You need to know what you want as thy are not marked. Are you sure it is a cap and not a resistor?
http://www.jameco.com/1/1/23404-12063c474kat2a-capacitor-ceramic-multilayer-25v-x7r-0-47-uf-surface-mount-1206.html

[maxmekker]

Surface mounted caps are available from some of the larger online sellers such as jamesco. You need to know what you want as thy are not marked. Are you sure it is a cap and not a resistor?
http://www.jameco.com/1/1/23404-12063c474kat2a-capacitor-ceramic-multilayer-25v-x7r-0-47-uf-surface-mount-1206.html

I don't have a clue, as to why I asked in post 44 what do they do (ore what is it)

[drwayne]

@grail.
Ceramics are rated 50 000 hrs in avionics when within spec. Diel's 200k, but then again my shed's 1976 transistor radio still works 24/7 !
Used within tolerances they're good
Chopper's youtube link amusingly shows caps outside tolerances.
'98 almost lost both legs when the ' cap array ' beneath an MRI blew itself to shi.t.
Lucky me, only lost half.

The T180 looks outside design tolerances to me, hey !

However, any high power setup will most likely exceed design expectations of the circuit. All these extra bits we hlue on the outside are done to defer imminent smoke.
ESC. Encapsulated Smoke Container

W

[drwayne]

Surface mounted caps are available from some of the larger online sellers such as jamesco. You need to know what you want as thy are not marked. Are you sure it is a cap and not a resistor?
http://www.jameco.com/1/1/23404-12063c474kat2a-capacitor-ceramic-multilayer-25v-x7r-0-47-uf-surface-mount-1206.html
Cap
If resistor it would be a shunt between inputs.
Or there's a track beneath the smt that feeds into pcb.
ive not taken the T180 apart to have component sheets.
W

[Basstronics]

I put together 3 cap banks over the weekend.

I used the FighterCat 5 cap bank board. I used Rubycon 1000 mincro farad caps 35V. The whole this soldered up easily using my weller adjustable iron and 1/16" tip and .030" electrical solder. Usually on PCB (Printed Circuit Boards) one has to be extra careful with the heat or you will lift a trace. These boards seem REALLY robust!

http://i38.photobucket.com/albums/e136/basstronics/RC%20Boats/100_1319.jpg

[drwayne]

They sound the biz. Are those boards assembled upside down ?
Show us a pic of the other side, plz.
W
ps .. off to work it's 0915 here.. so e patient for my next reply.
W


I put together 3 cap banks over the weekend.

I used the FighterCat 5 cap bank board. I used Rubycon 1000 mincro farad caps 35V. The whole this soldered up easily using my weller adjustable iron and 1/16" tip and .030" electrical solder. Usually on PCB (Printed Circuit Boards) one has to be extra careful with the heat or you will lift a trace. These boards seem REALLY robust!

http://i38.photobucket.com/albums/e136/basstronics/RC%20Boats/100_1319.jpg

[Basstronics]

Sorry they have black heat shrink with silicone on the ends now. I assembled them myself.

I hope I didnt assemble them wrong, but if I did I can fix... lol

[graill]

@grail.
Ceramics are rated 50 000 hrs in avionics when within spec. Diel's 200k, but then again my shed's 1976 transistor radio still works 24/7 !
Used within tolerances they're good
Chopper's youtube link amusingly shows caps outside tolerances.
'98 almost lost both legs when the ' cap array ' beneath an MRI blew itself to shi.t.
Lucky me, only lost half.

The T180 looks outside design tolerances to me, hey !

However, any high power setup will most likely exceed design expectations of the circuit. All these extra bits we hlue on the outside are done to defer imminent smoke.
ESC. Encapsulated Smoke Container

W

It is pretty funny to talk to folks and give specs and they say things "why would you ever do that" or "what are you building that would need that?!" good just to chuckle a bit at the insanity of some setups and attempts at pushing the edge of our hobbies available tech. :laugh:

[drwayne]

Looks like circuit tracks beneath the caps is why I ask. Also the leads ontop adds to the thought. Burn and learn, hey !
Hope Im just confused. W
Ps I hate tiny touch screen phones, so gard to typ.

Sorry they have black heat shrink with silicone on the ends now. I assembled them myself.

I hope I didnt assemble them wrong, but if I did I can fix... lol

[drwayne]

My favorite slogan is ' burn and learn'.
Sometimes to avoid the grief it's helpful to pre-emptively offer the 'why not' scenarios.
W


It is pretty funny to talk to folks and give specs and they say things "why would you ever do that" or "what are you building that would need that?!" good just to chuckle a bit at the insanity of some setups and attempts at pushing the edge of our hobbies available tech. :laugh:

[stractor]

I looked at the boards on Fightercat and they are parallel caps, the dark line is the void between + and - . The actual trace is almost 1/2 the board width, minus the void down the center.

[ray schrauwen]

Great thread Wayne. A side note on the ceramic caps. I did alot of testing a year and change back, a few observations with some input from Rubicon.

Ceramic, or solid caps last only 1/3rd the life of the newer film variety for our applications, high voltage, fast discharge. Not good for ceramic type caps.
When they "burn out" they turn to powder inside or simply dead short and do not explode or bulge as the fluid/film do most times. When you lose one you will have to test your bank to find it the majority of the time.
They DO NOT have the same high performance at high discharge that film does, at lower constant voltage apps, computer mobos, power supplies, tv, stereos, they rule over film caps.
To match the performance of a film cap the engineer said the solid caps would need to be much larger verse a film cap. The next question was what is the comparison for our applications, he said there is none. The two types could have close to the same numbers but in our applications the solids will always fail first.
DO NOT mix solid and film caps, even if specs are the same (which would be rare).

I spoke with an engineer at Rubicon least year and change ago and to get a ceramic/solid cap working like the film caps out currently would be cost prohibitive, pennies on the dollar to test and manufacture for the regular types compared to 9-25 bucks per cap to meet our applications.

**Rubicon Engineer** "Why do you guys do that anyway?" Reference FE boating.

Interesting on the film caps.

My brother is an audiophile and has tons around, the best in the world too. He knows his Caps and I don't mind using film caps of the right size and value if I knew what size and value to use??
He would not mind lending me some for testing. They are only about $35 -$50 each :scared:

Once he gets back I'll get some and snap some pics. He gets some custome made, then yer talkin' +$100 a pop.

I forgot how he always scoffed at manufacturers cheaping out on a great amp design using cheap caps or too many noisey electolytics. Then we modified the hell out of them with film caps and our ears were quite astonished.

Never thought of using them in this app. because of well, I just don't know?? Maybe because they are polarized??:confused2:

[drwayne]

Interesting on the film caps.

My brother is an audiophile and has tons around, the best in the world too. He knows his Caps and I don't mind using film caps of the right size and value if I knew what size and value to use??

My favorite amp is filled with glass, copper rails and excited electrons B). None the newer encapsulated smoke variety can compete against the pure aural joy once mine gets warmed up.

Caps. the correct ones to borrow from Bro' depend upon capacitance, resistance curve / return rates, batt pack discharge survivability, esc load expectations, and how much bang for effort you want. final bank size comes into play too.
Ive penned several 1P systems shared to large twins that survive anything thrown.. for that 90 secs for oval racing... and a few bitey single systems for sprint or SAW.

One size does not fit all . despite marketing otherwise.

That being said, 5000uf is a good start for generic system's esc and pack survival.
If you seek more output from esc., cooler packs, consistent high voltage flow .. then the additional capacitance needs to be tailored to suit.

More can be achieved than simple ripple clipping by smothering with cap ballast.

W

[FRED]

Question on soldering caps, ok.--- I noticed my turnigy 120 caps were 390-35v which i think are to small. I took the 2 caps off and replaced with 470-35v but my question is , can i twist 2 cap + wires together and solder to + side of esc. Next take the same caps-2 wires and twist and solder to - side of esc . Info asap before i use esc. To hot today for boating 93+ oh yes thanks.

[drwayne]

Question on soldering caps, ok.--- I noticed my turnigy 120 caps were 390-35v which i think are to small. I took the 2 caps off and replaced with 470-35v but my question is , can i twist 2 cap + wires together and solder to + side of esc. Next take the same caps-2 wires and twist and solder to - side of esc . Info asap before i use esc. To hot today for boating 93+ oh yes thanks.

Yes... so long those 'twisted' leads make sufficient contact the esc input rails, thats ok.
Do make sure the replacements are low esr with high temp survivability else they'll be 'rooted' very quick.

[ray schrauwen]

Thanks Wayne. When bro gets back from Phillipeans I'll ask him to help me out with the values and bounce your info off his.

Sounds good. What brands have you played with or think would be sufficient? I know he has used WonderCaps with audio PS's in the past but, I never kept an ear of what he's been using the last 10 years.

[maxmekker]

So today I got my small caps in the mail.
I got some 22 / 47 / 101 /221, they did not cost a thing.

I also got an answer from support at hobbyking, were I was asking the value on those small ones. The reply was that I could replace them with caps with 30v.
Since I don't know much about caps I thought maybe they were talking about the big ones, wich I'm replacing withe the ose etti cap bank anyway.
So I sent a mail to were I bought the small ones,asking the V range and heat range, but they have not reply's as of yet. Maybe some of you can help me out (wayne)
before I start soldering.

Also, can I cut the 'legs' to make them shorter ore will it affect the value/performance of the cap ?
Should I replace all with new ones, ore can I just try changing the damaged one first ?

The etti bank, best to fit it onto the esc ore can I have a short wire between? Not sure I have the head room in the geico if I solder it onto the speed controller.

thanks

[drwayne]

Hi
The original capacitors were rated as ?uf and ?V
HK have suggested you use 30V with original uf .. this is what I understand from your post here
The etti caps are a good replacement for the originals.. forget what HK have said !
The etti cap bank circuit board has holes for +ve and for -ve power wires.. make the esc wires go through that hole.. trim some cover from each wire so you can solder to it... use the wire that goes through the board to connect to battery.
Keep the cap bank close to the esc.. within 30mm is best.
"small" esc like the T180 will work okay with the onboard replaced by a much larger external bank

Id not like to see this 'cheat' on high voltage or high A esc as this creates issues with emf

regs
Wayne


So today I got my small caps in the mail.
I got some 22 / 47 / 101 /221, they did not cost a thing.

I also got an answer from support at hobbyking, were I was asking the value on those small ones. The reply was that I could replace them with caps with 30v.
Since I don't know much about caps I thought maybe they were talking about the big ones, wich I'm replacing withe the ose etti cap bank anyway.
So I sent a mail to were I bought the small ones,asking the V range and heat range, but they have not reply's as of yet. Maybe some of you can help me out (wayne)
before I start soldering.

Also, can I cut the 'legs' to make them shorter ore will it affect the value/performance of the cap ?
Should I replace all with new ones, ore can I just try changing the damaged one first ?

The etti bank, best to fit it onto the esc ore can I have a short wire between? Not sure I have the head room in the geico if I solder it onto the speed controller.

thanks

[maxmekker]

yes sir. The new small ones, I still waiting on reply as to if they are above 30v. Hope so :-)

you told me a 47 pf would be enough on that 180 some post's back, I asked Hobbyking but they use 5 day's answer so I just got some, then they answer,and say 30v ore above :-) I will see tomorrow if the caps I got are usable.

[drwayne]

Hi
The 47pf are toreplace the surface mounted caps that were damaged in one the pics above.. you still need the larger capacitors... although the etti cap bank can serve in their place...
you will still need the 47pf on the esc board to aid the system.
W.


yes sir. The new small ones, I still waiting on reply as to if they are above 30v. Hope so :-)

you told me a 47 pf would be enough on that 180 some post's back, I asked Hobbyking but they use 5 day's answer so I just got some, then they answer,and say 30v ore above :-) I will see tomorrow if the caps I got are usable.

[drwayne]

etti banks use 35V 1000uf x 6.

[maxmekker]

So it's ready for testing. Not exactly nasa stuff but it should hold up. The etti board was just a tad narrow to fit on my 180 board so I had to make some wires.

[1945dave]

8394583946
Question: I plan to add cap bank to Seaking 180 ESC, I bought this one: http://www.offshoreelectrics.com/proddetail.php?prod=etti-e041&cat=136. The recommended installation is to open up/strip the power wire near the base board and solder the + and - notches onto the wire. That will be difficult in my case, can I open up the power wires at the same location but instead solder two short ( very short , no more than 30 mm) wires and then attach them to the + and - notches on the cap bank?

Attached are photos of the newest version of the T-180 as I recieved it just a few weeks back. It now includes this little external bank of 4 capacitors wired in series across the battery leads. Notice the small gauge wire.Don't know what this brings to the table but my other T-180's do not have this bank.

Dave

[ray schrauwen]

They sell a 63V version that Maxmekker installed. Maybe a typo Wayne or do they have a 35V version too??
etti banks use 35V 1000uf x 6.

[ray schrauwen]

Looks more like parrellel to me unless you took off the heat shrink off the caps???


8394583946

Attached are photos of the newest version of the T-180 as I recieved it just a few weeks back. It now includes this little external bank of 4 capacitors wired in series across the battery leads. Notice the small gauge wire.Don't know what this brings to the table but my other T-180's do not have this bank.

Dave

[ray schrauwen]

It looked like it was going to fit.... but, should work the way it is. I'm sure you will insulate the bare wires??


So it's ready for testing. Not exactly nasa stuff but it should hold up. The etti board was just a tad narrow to fit on my 180 board so I had to make some wires.

[tlandauer]

I think it is wired in parallel, the small gauge wire suggests the maker does not bother to go the extra mile to include higher wire ga. However, as drwayne said earlier, efficiency is the main goal, I used 12ga wire to attach the cap bank, looks just like what maxmekker did to his T180. I did however replace the three caps that were originally on the ESC with identical ones bought here @ OSE.
I ran the same set up and everything was cool, the cap bank was barely 100* and so were the three caps on the ESC, the boat however suffered a flip and is down for the week while I do repairs to the FG hull, will report back, so far running with the added cap bank has really cooled things down.

[maxmekker]

It looked like it was going to fit.... but, should work the way it is. I'm sure you will insulate the bare wires??

just with some tape now. 2 set's of lipo's charged, and if it works, temps/speed etc are good, I will sit down and do a better job. soon to cold and dark here in Norway to do boating anyway,( when sept hit's it's like a switch, chilly and early dark)
but I have some fresh 65-130c 5000 lipo's just in the door I want to try out.

[drwayne]

They sell a 63V version that Maxmekker installed. Maybe a typo Wayne or do they have a 35V version too??
A diff branded 35V, sorry.
However, I'll cover my ass by saying I subconsciously intended to say cap voltage +20% of packs is best for power circuits.


just with some tape now. 2 set's of lipo's charged, and if it works, temps/speed etc are good, I will sit down and do a better job. soon to cold and dark here in Norway to do boating anyway,( when sept hit's it's like a switch, chilly and early dark)
but I have some fresh 65-130c 5000 lipo's just in the door I want to try out.
If it's cold outside, make sure your packs are warmed to ~body temp. makes for much better performance and longevity your packs.
W

[maxmekker]

Yea doc, got it covered. It's not that cold, just to cold to swim for the boat if it....... uho did I just say that..... hehe.

[maxmekker]

2 sets of lipos today, barely made it before it was to dark.
Sorry about the wind noise. 45-90c lipos first, then 65-130 later in the clip. Temp readings at the end.
It feels ok, not as strong as my friends mystic with the same setup though . Also it has some slight stutter as you can hear @ 1,44-1,46 and 2,25-2,27 in the clip .like it's cutting out a fraction of a second

Running a x442 in this clip. Will test with 642 an 445 tomorrow.


http://www.youtube.com/watch?v=jOFQzWVLniA

[tlandauer]

Looks great! I think the boat is really dialed in and very quick, do you think it is just you who thinks it is slower than your friend's?
I hear the stutter, but I am not knowledgeable to say anything.
In any case, glad you fixed the ESC and thanks to drwayne, I learned something very important!

[maxmekker]

hehe maybe. I'm just impressed with the mystic hull, better molded than my geico, that's for sure. I think I will try to add the mystic rudder during the winter, less stuff in the water 'behind there'

besides that it's running again, more packs tomorrow , will report back then to let you know how it holds up :-)

[Basstronics]

And I did assemble them backwards... d'oh.

Desoldering braid to the rescue!

[millzee]

Can I ask why is it bad to remove the old ones as pictured and run it as pictured? What happens? What will go wrong?

EDIT: That is if they have all gone bad, not if they were still good.

RE post #45
NOthing

[drwayne]

And I did assemble them backwards... d'oh.

Desoldering braid to the rescue!

Yep, that's what my edumacated eyes told me.

The metal canisters containing the capacitor should not touch any power rails.. and all yours touched both red/black !
That's a nasty short out waiting to happen... kerBOOM.


Millzee.
With low loading the capacitor bank alternative ( post#1) was good.
Under more demand, as informed, the esc failed.
Have exchanged one my own to the bloke who purchased that esc s/h.. he now runs with big smiles regularly
- I do hope to infuse life back into this deceased.
This how-to thread will hopefully educate the unlearned away from such cremations.
W

[millzee]

[QUOTE=drwayne;

Millzee.
With low loading the capacitor bank alternative ( post#1) was good.
Under more demand, as informed, the esc failed.
Have exchanged one my own to the bloke who purchased that esc s/h.. he now runs with big smiles regularly
- I do hope to infuse life back into this deceased.
This how-to thread will hopefully educate the unlearned away from such cremations.
W[/QUOTE]

so a x450/3, neu 1527 1.5d 1500kv on 6s in a df35 pirate isn't high draw?

[millzee]

I found the answer to my part in this, post #9 at the botom
http://forums.offshoreelectrics.com/showthread.php?23178-How-do-you-replace-the-caps-on-a-swordfish-240hv

Played yesterday and won both games, we wear green so the white is not an issue!!

[maxmekker]

More testing today,and it's holding up nice.

Only issue is the 65-130c lipo's and the m445 prop. I only had one pair of 45-90c so I could not test that and the m445 to se if that had any effect.

6 min's clip ore skip to 2,00 to see the M445 run. Not sure why, maybe anybody have a theory..


http://www.youtube.com/watch?v=egH2nbp6e5k&list=UURNlga8sE0qJBcPb_5FFovQ&index=1&feature=plcp

[drwayne]

More testing today,and it's holding up nice.
Only issue is the 65-130c lipo's and the m445 prop. I only had one pair of 45-90c so I could not test that and the m445 to se if that had any effect.
6 min's clip ore skip to 2,00 to see the M445 run. Not sure why, maybe anybody have a theory..
[/video]

maxmekker should take this to the video thread so lots more ppl can see and admire and comment

I see&hear the boat at speed surging hophophophophop on the prop.
X series props are low lift, but still too much for yours... x642+x442 show this by hopping the backside around badly.
Or.. and at 2.19 that bent edge made me wonder..are the props not sharp ?....
This will kill the esc due Amp spiking as it loads/releases on the prop.
LMK W

ps.. Love the great vid work showing temps and props.. where are the girls watching and cheering ?

[maxmekker]

Haha you are to funny. :-)

Well I dont do my props , I got them all done from funrcboats . I know they should maybe be DT ore maybe eveen sharper , but I can't sharpen props for sh....

The one I have used mostly, well all the time infact (since , like you point out, the boat is heavy on the whawhawha hophophop etc ) is the M445, that makes MY geico the most stable. I normaly don't use the X props I have, they work wonderful on my FRIENDS mystic, the boat flies with the X642 prop, and almost zero hopedihophopedihophopedihop, but he has been lucky with the mold of his boat. No need to fix the transoms, and the rudder assembly is wery clean from proboat on mystic compared to that on the geico boat.

Anyway , as you can se, it wont run on the 65-130c + the M445. I did not have another 45-90c lipo pack with me to test if that had any cause, next time I will :-)

I will drive it like it is for the rest of the month, and then it's on the shelf, and I'll just get a new one next year.

ps: the girls were in the bush's behind me getting ready for skinny dipping, unfortunately the camera was low on battery :-\

[drwayne]

the 65-130 are heavier than 45-90 ?
Move them back in the hull to reset cog.

You need to reset your priorities.
Girls first, playtime rc boats last.

W

[Paul21]

Hi couldt find info in forum search so try here hope it ok. So plan on running 12s on 5692 730kv sf240hv pro twin setup and need to find out what is used to stop spark when plug in batts and now to install it tks

[drwayne]

Hi
2 ways to set up 12S ..

either 12S a side..eg 4 x 6S packs
http://users.tpg.com.au/pcapps//twinparallel.JPG


or 12S shared eg 2 x 6S
http://users.tpg.com.au/pcapps//twinseries.JPG

Here's a deck mounted set
85581

Under the deck I place a piece of nylon cutting board ~10mm thick as support for the plugs.
I roughen madly before epoxy in place.
Drill through holes for main plugs + 1/32" for clearance
Insert presoldered plugs from inside hull, tape over top, invert hull and flood plug area with epoxy.
Wait 12+ hrs.
voila'.


The swordfish 240HV have an on/off switch.
The above picture show a deck mounted switch to remote this feature.
use a DPDT micro switch, remember to keep the 2 esc as separate entities at this switch. .

this diag shows wiring beneath the plug
. ___
esc1black---- |0 0| ----esc2black
esc1 red------|0 0| ----esc2 red
blank ---------|0 0| -------blank
.

[ray schrauwen]

How do you keep the momentary swich dry?

[drwayne]

How do you keep the momentary swich dry?

I flood with corrosion X before install and they last for ever ...

[ray schrauwen]

Very good!

Did you buy a 250A esc from alibaba? Someone "D. Wayne" bought one pending review. $108 + shipping or slow wait free shipping.

[justski]

ok new here what are the cap banks for what do they do ?

[tlandauer]

You might get a quicker answer by going back to the begining of this thread, I find this thread contains way more than just an answer to a single question.
Just a suggestion, please don't take it wrong, don't mean to be a smart a**.

[justski]

no problem ill go back i must of missed something ..thanks

[drwayne]

Very good!

Did you buy a 250A esc from alibaba? Someone "D. Wayne" bought one pending review. $108 + shipping or slow wait free shipping.
Im either Doc Wayne or Wayne S. !
Not D. Wayne, he is probably one of John's kin.
W

[drwayne]

ok new here what are the cap banks for what do they do ?

put your thinking cap on, and read this

http://forums.offshoreelectrics.com/showthread.php?36868-Cap-banks-the-pre-emptive-answer&p=448127#post448127

[jcald2000]

Doc, My cap's are coming in at 160 F (71C), should I add more caps?

[drwayne]

They're working hard !
What other temps do you have from that run ?
motor? leads? batts ?
any of those others in poor condition will quickly stress ( overheat ) caps.

extra caps may bot solve the complaint

Midnight down here in AU. will be back in 8 hrs !

[jcald2000]

Everything else is below 125F.

[drwayne]

Everything else is below 125F.

Damn !
Assuming
1. esc is not too small for your setup
2. timing is set right
and
3. motor is not 'free revving without load ' at 100% throttle . ?

yes..these caps need support !
What qty cells and what esc ? .. to offer some quantification of goodies required .

W.

[jcald2000]

90145

SF240 and Hyperion or Dinogy 5000's with 1527/1y

[drwayne]

90145

SF240 and Hyperion or Dinogy 5000's with 1527/1y

Wow. 313A max.
The caps are hot because the esc is working at 130% its design.

I recommend the set as per this link
http://forums.offshoreelectrics.com/showthread.php?36868-Cap-banks-the-pre-emptive-answer&p=447942#post447942

Use 63V 470uf as per that circuit.

make the capbank fit inline between esc and batteries as per this attachment.

90146

let me know the next log results.
W

[jcald2000]

300 burst rated, subed on takeoff.
So, 6 caps series + parallel as shown?

[drwayne]

Mildly concerned of damage to esc caps.
Test the onboard caps, in circuit.
All will return same if ok.
If not same, the recommended bank is insufficient.

Enjoy !

[viper1]

Wayne;

Very informative thread, learned heaps, thanks for that !

A question: I've read -someplace I forgot-, that when adding a cap bank that (more) smaller caps were better than (less) bigger ones, assuming they both would add up to the same capacitance.
Had something to do with discharge speed but not sure?

Also does the wiring thickness make a difference at all on short lengths of say 2-1/2" / 6cm?
I found the wires quite thin on my 180 V3 for the cap bank, and thought about changing them, but looking at leads of the caps itself, all these little electron guys will still need to 'squeeze' through those tiny leads right? Your thoughts?
I understand the necessity on longer lengths.

Thanks in advance

P.S. 'Schutte' , Dutch heritage?

[ray schrauwen]

The capacitors are flattening the AC ripple current not the DC drive current so, that's how T180 v3 gets away with thin leads. I've used 14G wire before on a hot 6s2p setup and it's just fine.

[viper1]

But.. (don't you love starting replies with that....) I understand part of what you say, the part where the caps are not taking the full current, but now you brought up another question: how can it flatten AC current, shouldn't they be mounted on the output side (AC) -in this case motor leads- as the input is DC right? I thought (and apologies for using layman's terms, otherwise I wouldn't even understand my own typing:smile:) that the caps store energy -from-battery- and deliver extra during peak pulses when batteries can not deliver that quick to the esc.

[ray schrauwen]

My electronics theory is old but, the basic rule is that capacitors pass DC CURRENT but, block AC CURRENT.


Why block it on the input since you say it is connected to a pure DC source (lipos) ? Well Backemf (http://www.acroname.com/robotics/info/articles/back-emf/back-emf.html) is the reason I think?!

Thats not the best link for the information. Someone posted the correct explanation in an old thread of BL motor theory.

Basically when any winding is energized (pairs are energized at any given time on our BL motors) it forces the core armature to move until it is de-energized (shut off). When power is disconnected from the winding the magnetic energy field in the coil collapses and this collapse sends a BACKEMF voltage in the other direction back into the esc. This is (I think) is where/when the caps settle that returning ac waveform. This happens at a frequency that you set your esc to :wink: like the 8Khz or 16Khz, etc. This is a ac wave in the form of Pulse width modulation PWM, square wave.

I'll take any lambasting for any mistakes in here. I took my best shot. lol... :blah:

[kingwrench]

Dr Wayne as I told a youngster today I learn something new every day. Thanks again mate

[drwayne]

@Viper1 .. seems you missed the meat in sandwich.. read lower half of this post re ac/dc ripple
http://forums.offshoreelectrics.com/showthread.php?36868-Cap-banks-the-pre-emptive-answer&p=448127#post448127

@Ray. Shhhh. .. :) you have confused logic answering Viper1's misunderstanding

[drwayne]

The comment more small Vs large is/was mine ( dont remember where)
The T180 micro external cap bank has less joule return than a single 35V470uf used onboard that esc. The extra are fine for high freq ripple clipping, not more.
Leads.. if the caps have high charge/discharge, why starve them with low yield wires ?

[ray schrauwen]

@Viper1 .. seems you missed the meat in sandwich.. read lower half of this post re ac/dc ripple
http://forums.offshoreelectrics.com/showthread.php?36868-Cap-banks-the-pre-emptive-answer&p=448127#post448127

@Ray. Shhhh. .. :) you have confused logic answering Viper1's misunderstanding

Aaaaaaaaaaahhhhh!!!!!! :bowdown: :hide:

[ray schrauwen]

Dr. Wayne sums it up again. THIS is a fairly simple version also:




The way capacitors and resistors behave is totally different. While resistors allow a current to flow through them which is proportional to the voltage drop across the resistor, capacitors oppose a change in voltage across them by either drawing in or supplying current as they charge or discharge resp. The flow of current through a capacitor is thus directly proportional to the rate of change of voltage across it.

This is given by the relation, i = C* (de/dt) where de/dt is the instantaneous change in voltage.

As the voltage does not change in the case of DC, de/dt = 0 and the current that is allowed to pass through by the capacitor is 0. For AC voltage the voltage changes in a regular manner. Hence here de/dt is not 0 and a current is allowed to flow through by the capacitor.

[drwayne]

@Viper1
This thread discusses purpose, benefit and variants of capacitance buffering/filtering of the DC input to a brushless ESC ( DC->AC 3 phase inverter. )

Capacitance on the output side has merit, but will not be raised in this thread

ps. 'Schutte' is of German heritage.
Thyer, Schutze and Spier are some previous title holders of last remaining male of this bloodline !

[viper1]

@Viper1 .. seems you missed the meat in sandwich.. read lower half of this post re ac/dc ripple
http://forums.offshoreelectrics.com/showthread.php?36868-Cap-banks-the-pre-emptive-answer&p=448127#post448127




AAARgh, must have been reading to quick, missed that part, crystal clear, probably got distracted by the simple drawing above it...simple seems to attract me more :olleyes:


The comment more small Vs large is/was mine ( dont remember where)
The T180 micro external cap bank has less joule return than a single 35V470uf used onboard that esc. The extra are fine for high freq ripple clipping, not more.
Leads.. if the caps have high charge/discharge, why starve them with low yield wires ?

Pretty sure I got it from a Dutch forum, but covered more the esc's in general, forget the 180, I hear you. What I meant was that all the caps are smaller, but added up have same value as bigger uF's, less in quantity. ?

Re the leads; OK bigger is better, but has it benefits to go thicker than the solid wire coming out of the cap itself, when mounting directly against the ESC ?


@Viper1

ps. 'Schutte' is of German heritage.
Thyer, Schutze and Spier are some previous title holders of last remaining male of this bloodline !

Thought it sounded vaguely familiar for a 'cheese head' :biggrin:

[drwayne]

Pretty sure I got it from a Dutch forum, but covered more the esc's in general, forget the 180, I hear you. What I meant was that all the caps are smaller, but added up have same value as bigger uF's, less in quantity. ?


Factual data on capacitor performance is no mystery, however application in array form is not common knowledge amongst amateur electron gobblers.

Re: many small Vs few large equals same capacitance.
Charge/reply on a small cap is faster than a large.
Many small caps can buffer a ripple more efficiently than fewer large where their response is slower.

Schutte: from a long line of brewers, beer drinkers, engineers and all round good guys.

[viper1]

Factual data on capacitor performance is no mystery, however application in array form is not common knowledge amongst amateur electron gobblers.

Re: many small Vs few large equals same capacitance.
Charge/reply on a small cap is faster than a large.
Many small caps can buffer a ripple more efficiently than fewer large where their response is slower.

Schutte: from a long line of brewers, beer drinkers, engineers and all round good guys.

Thanks Wayne,

In different words that's what I remembered right then, discharge speed or as you called it response time.

I wouldn't have brought it up if I got it from a amateur

With the cheesehead comment I was refering to myself, to be honest, I would't mind the foamie stuff in the ancestry either.:beerchug:

Thanks again mate

[drwayne]

Thanks Wayne,

In different words that's what I remembered right then, discharge speed or as you called it response time.

I wouldn't have brought it up if I got it from a amateur

With the cheesehead comment I was refering to myself, to be honest, I would't mind the foamie stuff in the ancestry either.:beerchug:

Thanks again mate

Most welcome mate.

Find me a baker, we 3 open a Beer Hall, eat and drink to a merry old tale . :thumbup:

W

[drwayne]

Re the leads; OK bigger is better, but has it benefits to go thicker than the solid wire coming out of the cap itself, when mounting directly against the ESC ?:

The solid conductor eminating from capacitor has higher resistance than multistrand cable. To have a capbank connected a high demand circuit via a cable/conductor with avoidable resistance is poor design !

W

[viper1]

Sigh.... sorry, I understand your answer, but I'm afraid I didn't make my question clear enough. I didn't mean using the solid cap leads to connect the bank.
Let's say for example I have a cap bank, connected with e.g. 12 AWG wires to the ESC, does it have benefits to go to thicker, e.g. 10 AWG wires.
The chain is as strong as the weakest link is what I'm thinking, and in this case both the wire diameters far exceed the cap leads. so would it make a difference really?
All assuming this is on short lengths < 8 cm.

My wire examples are exaggerated but both are thicker then the solid cap leads

[drwayne]

Sigh.... sorry, I understand your answer, but I'm afraid I didn't make my question clear enough. I didn't mean using the solid cap leads to connect the bank.
Let's say for example I have a cap bank, connected with e.g. 12 AWG wires to the ESC, does it have benefits to go to thicker, e.g. 10 AWG wires.
The chain is as strong as the weakest link is what I'm thinking, and in this case both the wire diameters far exceed the cap leads. so would it make a difference really?
All assuming this is on short lengths < 8 cm.

My wire examples are exaggerated but both are thicker then the solid cap leads

The T180v3 external cap bank is connected by awg22 wires... very small by comparison the main battery leads.
However, the caps are also very small, and their charge/discharge is low yield.

Larger capbank charge(joule) movement will create a heat dynamic in the wire.
DeltaT in wires of AC is higher than it's DC rms equivalent..
Ive replaced many caps on escs where the cap leads have burned under load.
By provisioning the capbank with larger connect cabling, that temp dynamic is reduced... lower heat, lower resistance, better for all...

emoticons here are good. sigh ? ..try :frusty: or :doh:

burn and learn, mate. :flame42:

[viper1]

Got it ! :doh::crying::olleyes::rockon2::thumbup1: Soooo Thick :blush:

Replaced the wires to 16 AWG while I had the ESC apart for my 'cooling mod' (http://forums.offshoreelectrics.com/showthread.php?23772-Turnigy-180-cooling-upgrade&p=485165&highlight=#post485165) but still using original caps.
Kept 'm a bit shorter as well.

Thanks for your patience !

[drwayne]

If ever we meet face2face, Im rarely as cool or patient as here !
Saw the flyboy toys, nice.

Best of luck with boats.
DocW
:beerchug:

[viper1]

If ever we meet face2face, Im rarely as cool or patient as here !
Saw the flyboy toys, nice.

Best of luck with boats.
DocW
:beerchug:

If ever we meet face2face,....I'm more ugly, but not so dumb !

Thanks, gonna need all the luck I can :Praying:

Salute :beerchug:

[Brushless55]

WOW!
my hopes are high for my T180 in my TP powered PMono now reading through this thread :banana:
I was unable to finish all six laps as I could only finish 5 1/2, now it may just be bad caps :sneaky2:

[Mike Caruso]

If ever we meet face2face, Im rarely as cool or patient as here !
Saw the flyboy toys, nice.

Best of luck with boats.
DocW
:beerchug:

Hey Doc,
Hows this info http://www.niccomp.com/help/ESR-RippleVoltage-032012.pdf
Thanks Mike

[ray schrauwen]

Wish I read this before I made a cap bank for my SF200. The cap bank wires actually burnt open and esc died even after trying again with new caps. I didn't really think the wire guage mattered too much but, now I know it does. Thanks Dr.Wayne!


The T180v3 external cap bank is connected by awg22 wires... very small by comparison the main battery leads.
However, the caps are also very small, and their charge/discharge is low yield.

Larger capbank charge(joule) movement will create a heat dynamic in the wire.
DeltaT in wires of AC is higher than it's DC rms equivalent..
Ive replaced many caps on escs where the cap leads have burned under load.
By provisioning the capbank with larger connect cabling, that temp dynamic is reduced... lower heat, lower resistance, better for all...

emoticons here are good. sigh ? ..try :frusty: or :doh:

burn and learn, mate. :flame42:

[ray schrauwen]

This is a pic of what happened to my cap bank. I did shrink wrap the bank but, did not insulate the bare soldered leads:doh:.

Even if I had insulated the leads, the wire I used to connect them to the SF200 was too thin as well as you can see.

The boat runs dry so it wasn't an abundance of moisture that did it, more of an arc possibly from the AC but, I'm guessing at this point.

Anyway, thicker wire is better, closer to the esc is also better. At least no magic smoke, the driver Fets blew.

[drwayne]

Hey Doc,
Hows this info http://www.niccomp.com/help/ESR-RippleVoltage-032012.pdf
Thanks Mike

Hiya :smile:
The main part of your quoted link appropriate to our use is the cap application to automotive audio power rails.
Although for my 12S setup..I didnt find any Sub-amplifier capacitor boost bank capable of 40k 50V 300A !
We are at an extreme of power demands not catered by any the 'domestic' boom box fraternity...



This is a pic of what happened to my cap bank. I did shrink wrap the bank but, did not insulate the bare soldered leads:doh:.

Even if I had insulated the leads, the wire I used to connect them to the SF200 was too thin as well as you can see.

The boat runs dry so it wasn't an abundance of moisture that did it, more of an arc possibly from the AC but, I'm guessing at this point.

Anyway, thicker wire is better, closer to the esc is also better. At least no magic smoke, the driver Fets blew.

The way you have soldered the caps, forces that last cap's leads to support the feed/discharge from the others.. this doesnt work well as it will likely burn ( see your pic )
Use a basic plain circuit (insulating) board to support your caps, and run the larger connection cable across the base of all the appropriate leads emanating from the caps.

Expect your cap bank to demand/supply the same ( or greater) power as supplied by your power source(batteries)
Logically if your battery/esc uses X-AWG cables..that is the same size required to/from your buffered power source/array ( cap bank )
A quality cap bank will emit a pulse 8x larger than the battery if you short the leads.. so why diddle with small cables when there is such a large discharge potential ?

Note of interest: it has been observed if my safety loop disconnects.. I have another 3 seconds on water run time before the cap bank is depleted and power stops.
3 seconds of 'full' power.. so please dont expect servo sized wires to support that power flow !

Pfft zap :flame42::

[rickwess]

For those building their own cap banks. Just cut it shorter to match the number of caps you want to use.

http://fightercatracing.com/index.php?page=shop.product_details&product_id=308&flypage=flypage.tpl&pop=0&option=com_virtuemart&Itemid=1

[drwayne]

For those building their own cap banks. Just cut it shorter to match the number of caps you want to use.

http://fightercatracing.com/index.php?page=shop.product_details&product_id=308&flypage=flypage.tpl&pop=0&option=com_virtuemart&Itemid=1

Head to RadioShack, Tandy, DickSmith, Force, Jaycar, RSI, Fallands, or whatever your country has in the way of electronics super stores and grab a piece of plain predrilled circuit board... 2 or 2.5mm spacing ..
The worst Ive seen was $3 for 4"x2"(100x50) !

The FC jobs are nice, but +$6 for their embossed name on a Chinese product? tsk tsk

[rickwess]

I like the substantial + and - buses on the PCB. It keeps it nice and clean. I'll spend close to $3 on the heavy awg wire to join the caps together and it won't look nearly as nice..

[ray schrauwen]

Yeah, you are right Wayne. I screwed up.

I have all the stuff to etch pc boards, should have done it in the first place, lazy, tsk tsk...

[drwayne]

Hmm

Yes, these FC labeled boards are a nice 'off shelf' item sourced from China.
The final connection from those boards to leads is via a 5mm solder pad... on 0.5mmX6.35 tracks.

Say a 6S setup.. some 22VDC with an expectation of some 250A peak .. ~5500W
Say an induced ripple of 2.2VAC = ~550W of heating..
Say 6S 1800Kv = 39600rpm = 118800hz ripple.
I say stand back !

This thread was initiated to circumvent people using rtr/offshelf fix-all solutions to our ever increasing demand for power and supply stability... without understanding the potentials and demands involved in their pursuits.
I applaud your enjoyment of the FC product.
Sadly they do not cater all needs presented at this forum.
cheers !

[drwayne]

Yeah, you are right Wayne. I screwed up.

I have all the stuff to etch pc boards, should have done it in the first place, lazy, tsk tsk...

Creating your own circuits is an admirable talent, but the tracking would need be 1/16 to support the currents expected here.
Look at post#12 for an alternative method to what you intend to lay up.
W

[millzee]

Hey Doc, how ya been?
I'm hoping you can reassure me that this wiring will be ok for my 10s set up
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/esc001_zpsd1b60d42.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/esc001_zpsd1b60d42.jpg.html)
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/esc002_zpsdcd3d588.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/esc002_zpsdcd3d588.jpg.html)

[viper1]

Hey Doc, how ya been?
I'm hoping you can reassure me that this wiring will be ok for my 10s set up


:tape: :blush: :popcorn2:

[drwayne]

Hi Danny. long time !
1) the soldering of join at 2xESC join with the 14AWG cap leads is poor
2) what capacity the bank & what type the caps ?
3) I do approve the ESC and plugs on ends those leads :thumbup:

W

[millzee]

It's the large Etti cap bank. Should I use thicker wire to the cap bank or is the 14awg enough if I resolder the join with a 400 degree iron and make sure they don't move when cooling?

[drwayne]

It's the large Etti cap bank. Should I use thicker wire to the cap bank or is the 14awg enough if I resolder the join with a 400 degree iron and make sure they don't move when cooling?

The Etti bank is 50V ?? uf
Yes, the soldering iron ( or technique ) needs to be better than what was used originally.. I use an Iroda 300W gas pistol grip thing that does a damn fine job.. be careful the heat doesnt travel up the wires into the esc or you'll roast it !
Although solder is a good conductor, it has limited tolerance to high current flow ( and residual heat build up ) .. more wire to wire contact at that joint is a must .. the 14AWG wires to cap bank suggests it is not capable to feed the quad 8AWG inputs to the esc....

If outside your comfort zone, mate ... post it over... I'll fix :smile:
cheers.
DocW

[ray schrauwen]

2) what capacity the bank & what type the caps ?

W

This Etti Cap Bank has a total of 5000 uF ( 5 x 1000uF) They are Rubycon RX30 63V 130*F caps.

[millzee]

thanks ray, my internet crashed for a bit there

[millzee]

How's this, I used a 8mm bullet that I squashed a little to fit both the esc wires into and up the cap bank wire to 10awg.
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/join001_zps558356ef.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/join001_zps558356ef.jpg.html)
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/join002_zpse9521c16.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/join002_zpse9521c16.jpg.html)

[drwayne]

-Much better than before.
-Novel approach to joining the 2x esc leads :smile:
-The 8mm female would have accepted the 2xESC leads and the cap lead simultaneously .. ..a bit awkward now for heatshrinking.. that's an observation.
- The cable length from 8mmF join to the final male plug looks long.. does it need all that length ?,, shorter leads allow higher current flow ..

Looks promising, mate !

[millzee]

Cheers mate. The leads need to be that long to fit where they're needed. I've put it all together and programmed the esc so I now have another boat ready to run that'll have to wait a week or so due to work commitments. (I've been stuck in the office for a couple of days and that's been a great help catching up on unfinished projects)

[Steven Vaccaro]

excellent idea on the connector.

[rickwess]

This is by far the best method I have seen (courtesy of Doug). I had built a beautiful set of T connectors out of bullets for my 2p setup then had a "V8 moment" when I saw the pic. The gauge of wire wrap is unimportant.....the thinner the better to get a tight wrap. I'm using 22 or 24awg CAT6 wire. It's really just a binder until you solder it.

Easy to shrink wrap too.

108145

[tlandauer]

Wow, yes, it looks very intelligent! :rockon2: Now for the unintelligent stupid question I have: suppose you still use your "T" connector and "save" one pos. and one neg. for a cap bank, would that work?

[rickwess]

It would work, but it is another connection, which in practice you want to avoid. I think it would be better to just bind another set of wires into that splice for the cap bank.

[drwayne]

The less individual joins or loops or bypasses or extra traffic on the leads is always best.
rickwess's wire wrap idea is a frequently utilized idea, and is good to see it represented here.
Do use a large tip high wattage iron to quickly put solder through that join, else the solder will wick up the leads making it a most unsatisfactory product.

Yes, Id solder leads from a cap bank to that same location...

[rtodd1405]

Hi,

I've read all these comments and great advise and have to say that I'm impressed by the detail but still a little confused. I wonder if you may be able to help. I'm building a boat 56 inch carbon fibre cat with twin drive. I have bought Castle 2028 (740Kv) motors and still to buy the esc's and batteries. I am thinking of Swordfish Pro+300A esc's and twin Entropy 6S in series to give 12S on each side.

I already have some 63V 470uf RB capacitors and not sure just how many I need to use on each side. From your photos etc. I think I need two capacitors side by side in series (one row) but I'm not sure of how many rows in parallel? I'm not sure if it is 6 rows (12 caps in total) or 4 rows (8 caps in total)?

The other thing I'm not sure about is whether the two sides (ie. the batteries) should be connected in parallel (at the capacitor bank) or left completely independent? I've been told that this helps balance the loads on the batteries?????????

Any assistance would be greatly appreciated.

Russell - Brisbane Australia

[rtodd1405]

Ps. one more thing, do you know what size resistor I should use in the spark arrester??????

Russell - Brisbane Australia

[drwayne]

Gday :smile:

if you hope to race this inside AMPBA rules, 12S1P for the whole boat is your limit.
A pair 2028(780Kv written on back of mine btw ) is too much for 12S1P :(

resistor is 100 ohm 5W ceramic ...
63V470uf 105c caps available in Au from Jaycar RE6210

here is the last capbank for a SF300 feeding castle 2028 in sprint hydro.
All cables are AWG8, plugs 8mm with cables when entering the plug are doubled so more wire less solder ... ergo I stripped more insulation from outside wire, folded the exposed and forced into plug.. then soldered
16 caps in total set as 8 series pair connected in parallel ( wtf ? lol )
The Sf300 here is my old faithful :lol:

112113

Here are 3 pair of series caps connected in parallel

--||--.--||-- is a pair of caps connected in series...

112114

[rtodd1405]

Wayne, thanks very much for the info.

Your right, the motors are 780Kv.

Much appreciated

Russell - Brisbane Australia.

[Fluid]

...I'm building a boat 56 inch carbon fibre cat with twin drive. I have bought Castle 2028 (740Kv) motors and still to buy the esc's and batteries. I am thinking of Swordfish Pro+300A esc's and twin Entropy 6S in series to give 12S on each side...Another issue with your motors, 12S is too much for the Castle 2028 motors. First, they are rated to 30,000 rpm and 12S will be at their limit. Second they will need some relatively small props, and that hull will move better with large props. Unless you want SAW-type running only best to limit voltage to 8S or 10S per motor.



.

[drwayne]

Another issue with your motors, 12S is too much for the Castle 2028 motors. First, they are rated to 30,000 rpm and 12S will be at their limit. Second they will need some relatively small props, and that hull will move better with large props. Unless you want SAW-type running only best to limit voltage to 8S or 10S per motor.

.

Hi Ray.
The 608z bearings inside these castle 2028 are 8mmID 22mmOD 7mmWide
They are in fact skateboard bearings made in Singapore...as labelled and later identified from manuf.
Do yourselves a favor and replace these wheels with better.
Bearings are the failing of this motor.
I went BOCA :smile:
Be aware there is a bloody o-ring on the shaft internal as a spacer !

Seriously wtf ? hahaha

regs
W

[Fluid]

What about the rotor wrapings doc, that is a more common BL motor failure point due to over-revving than bearings are.


.

[rtodd1405]

Hi, many thanks for your comments and good advise.

Thanks

Russell - Brisbane Australia

[mekzoid]

I just bought a swordfish 300 with the castle recommend cap bank which is http://shop.rcboatbitz.com.au/index.php?main_page=product_info&cPath=73_76&products_id=868

Would that be sufficient?

[drwayne]

it depends on your loading.
for a 1515/1Y on 4S likely ok ..
for a 2230/1Y def not.

What motor + expectations ?
W

[mekzoid]

Sorry dur, I should have given more info, CF cheetah, TP 5660 1420 kv running 8s with a prather. Should I add another cap bank looking for the fastest cheetah out there so 75mph plus with a Prather 245 and Prather 240. I already bought 1 cap bank as stated.

[drwayne]

higher volts and lower Kv would make things easier ..

If you already have motor and packs..Id rec another the same cap bank and play gentle .

Talk to SteveB or DavidK in Qld about your needs ... :)

[Fella1340]

Great reading, I could have continued on for ages. Glad to see its still current as I have a couple stupid questions of my own to add soon:smile

[drwayne]

They're only stupid questions if you present them after something went wrong .................

[Fella1340]

Hello Doc, I am wanting to know how much is to much. I am building a 50" semi scale mono of the P1 Fountain. It's been heavily reinforced with multiple layers on cf and kevlar from stern to bow and top and bottom. A heavy boat. I will be running a TP 5660, 820kv, 6wye motor and swordfish 300 amp pro plus esc. Batteries will 10s2p 10000mah 30c minimum. Long before reading this I purchased 2 cap capacitor banks from rc boat bitz. This is where you smile because you know exactly what I have but will add it now for the record. The capacitors are 50volt, 1200uf each and a total of 10 each for 12000uf. I have purchased two of these and at the time was digging how they would look in my setup. Having them in hand they are much longer than I would like. In this case after reading and gaining an understanding of the importance of having them I will choose function over form. They are well made with 8 ga wires coming off the board. I also bought the sword fish parallel /anti-spark board. The idea being to series a 6s and 4s together for each side and them make the parallel connection on the board. My original thoughts were to connect the cap bank one on each side of the four battery leads before it got to the board but if I understand a little better now I would be best making the connection are the parallel antispark board. My basic understanding is vastly improved, especially the relevance part to our hobby. What would you recommend I do? I would prefer to run 2 separate banks to help these fit into the build as a lot of time is going into making this look as nice as hopefully it will perform. What I would prefer and the reality of how this is has to be done may be at odds to one another. Both sets totalling 24000uf. Back to the original question. How much is to much? Cutting and changing the number of caps is no problem. I hope you can help me out doc as that part if the project is only a couple weeks away. I also have another one to tackle after this one. The use of a power regulator (2s power) and a cap bank in a single engine fast electric running 3-4 hv servos. One under heavy load. Fun project! Thanks Doc, look forward to hearing from you. Jeff

[drwayne]

5660?.. why not 5850 ??...

One of the RCBB 12000uf cap banks will be most adequate your needs.

Be warned .. when you connect 10S2P to the cap bank it will throw a spark intense enough to cause bowel motions .... :laugh:

The addition of a resistor to soft charge the caps will offer no degradation of performance .. but will likely save a repetitive cleaning bill !
Also saves the plugs from damage.

Hook batteries together as 10S2P. press and hold down the little switch for 10 seconds.. this will slow charge the caps.. so when you then make that final connection to the ESC there is no blinding flash ( or mess in your trousers )

113302

[Fella1340]

Thanks Doc,
I really appreciate the help. I am not sure I understand what you mean by using the spark resistor. The parallel board has the anti spark resistor post built in , would it not charge the caps on board it as well as the cap bank I am going to install? I really like the momentary push switch charge idea, much better than having a dangling lead! That's the best way to discharge the caps after running, won't just pulling the wire leave a potential for quite a bite from the stored energy? Now I need to find a home for this extra-long bank. If I was making my own what would you recommend? is there a better solution more personalized to my setup you can recommend? Just because have the "one sixes fits all version" doesn't mean I have to use it. I would prefer the best solution over the easiest any day of the week
Why not the 5859? I am already modifying the motor mount to accept the larger motor. Seeing your comment is leading me to just order the dam thing. It was recommended awhile back and I bought it. A 5850 just may be in there before this hits the water! Thanks again. Jeff

[drwayne]

Hi
The parallel board from HIFEI is intended to make wiring the SF300 simpler task.
The 2 black and 2 red 6AWG input wires are a pain in the arse!! . and the board makes that connection a bit easier.
All that said, I do not like the diminutive size of it, and the lack of separation between rails (power sides ).
On your best day there is still a chance a drop of H2O may strike that board .. instant roasted karma .

Thus my suggestion of push button spark eliminator removes need for the board.

When the 'LOOP' as detailed above is disconnected end of a run .. application of throttle (the 'FINGER') will drain whatever residual power is stored within the cap bank to a safer level.
The datalog will show a sudden spike of amp draw during it's last few seconds of life.. be aware this is due the voltage drop off and power loss from it's supply..panic not !
^^ keeping Tx/Rx active during this time would be of paramount importance !

'Loop' does not need to be a physical loop of wire for removal.. it could well be the single last link between parallel batteries and the capbank/esc interface..
In some countries ( like mine ) an external mains power disconnection safety loop is mandatory .. so my diags tend to cater those users :smile:

If you're ordering a new (medium budget) motor to suit your beasty .. I do thoroughly recommend the Castle 2028 for 10S...
I openly admit I was stunned in admiration of it's performance when abused by my 'Go Finger' !.
Steve here at OSE supplies a decent 5" rail mount for this motor at ~$60USD..

regs W

[Fella1340]

Thanks for taking the time to tell it like it is. I really disliked they parallel board but it grew on me as time passed because it was a good solution for those god awful wires. Looks like I will ne joining them up, adding the 6ga cap bank wires and the push putty system in. All on 3" of wire. Not happy with the reality of that let me tell you! There's nothing worse though than being told what you want to hear though, thanks for providing me with the solution. I have come to very much dislike the entire sf300 layout altogether. I know what I have to do now, your help here is saving people a lot of time, frustration and many. Hold that, the sf is still going to frustrating. If it was just a race setup it would be of little concern but I am attempting a clean build and will have ti rethink the whole thing.
I stopped receiving email notifications by email over a week ago and cannot fix the problem so forgive my slow response time, thanks again. I will be back to chat about the rx power system, gryphon power regulator and hv servos and a cap bank for Ã*!**t once I have things organized.

[drwayne]

A friend has previously shown work using a Female 8mm plug,,the 8mm entry side, slightly crushed into an oval shape, makes for an ideal spot to insert 2 red esc 6AWG input cables to make a join.. and another plug similar hammered for black.. the other side the female plug is a pre-made solder point for 6AWG to lead towards whatever else is in circuit. !
I assemble and trim 1/2" off one of each color so the plug naturally lays off to side the esc when all done ..
Use double or super good heatshrink
:smiile:

2358 here atm.. time to go count sheeps.. :)

[Fella1340]

I will be making a couple oval connectors. The female plug thing is great. Thanks for helping again.

[rickwess]

Hey Jeff. Take a look at post #145 in this thread. IMO, a better way to connect the wires. I did a variation of that when I built my mono and needed to connect two batteries and a cap bank to the ESC. I used wire from a CAT6 cable to wrap the wires and 3:1 heat shrink with the adhesive liner to cover the joint.

113417 113418 113419

[Fella1340]

I was considering doing something like that as well, was going to use 6ga after the connection to the bullet to the battery. I will be paralleling (2x6s+4s in series)10s2p into it. Just thought it may be better. Running 10s 2p into the single set of 8mm bullets would be the bottleneck point then. I am not sure what the 8mm bulet's are rated for, I really would have liked to use the parallel board as it would have made things much nicer. I wonder if making a copper buss for each side would make things work better. Makes you wonder why they don't make the bullets out of copper, anyone know why. Hope the above makes sense.

[srislash]

I was considering doing something like that as well, was going to use 6ga after the connection to the bullet to the battery. I will be paralleling (2x6s+4s in series)10s2p into it. Just thought it may be better. Running 10s 2p into the single set of 8mm bullets would be the bottleneck point then. I am not sure what the 8mm bulet's are rated for, I really would have liked to use the parallel board as it would have made things much nicer. I wonder if making a copper buss for each side would make things work better. Makes you wonder why they don't make the bullets out of copper, anyone know why. Hope the above makes sense.

I have kinda wondered that myself. Copper is too costly and soft perhaps. Brass is a terrible conductor though.

[drwayne]

The Castle 8mm bullets have thin walls on the female compared the much thicker HK variety..but the metallurgy has visible differences too.
I see Castle claim 200A capability for theirs. which really means bugger all ! :lol:
200A at 1V .. or 200A at 50V ??
I have pushed the HK thicker wall plugs beyond 400A on 50V without issue...
The less contact(cup size) and conduction density of the Castle plugs my only deterrent .... now using the HK as alternative ...

Copper rails from mains power electrical boards are cumbersome to translate to RC ..
Our Australian 240VAC 10A fused rails .. 2400W .. are well below the needs some our 44V setups here
eg 10S2P10000 where 40/80c translates to 35200W !!!!!!


regs
W

[Fella1340]

I am still trying to understand how gold plated brass is better. I am set up to do small item plating, would making copper bullets and gold plating them be a better solution? It's not something I would want to do all the time but for arguments sake if I went to the trouble to make a set or two for this specific application would conduct better and stay cooler? I am tempted to do an experiment between gold plated brass versus gold plated copper. I have telemetry and could use a temperature sensor on the final connection, before batteries.
What do you think Dr. Wayne? Get over it and just run the hk bullets or would copper bullets be worth a shot? It just doesn't seem proper to run a double set of battery leads down to a single connection where batteries are paralleling into them. I got everything plus the kitchen sink to make and plate something up. If you had a better idea for a fella like me with to much time on his hands to try out I would love to hear it. I don't know what being practical is like with this stuff and could use some perspective on this. How could the same thing in brass be better than copper other than expense? Slap some sense into me!

[drwayne]

your packs have either 10AWG or 8AWG.. the esc has 2x8AWG uptakes

"Theoretically" the best option is for zero reduction of intake cabling, and I accomplish this via battery and esc connections at the cap bank which fits between packs and esc.. not as a external bank as the ones you have from RCBB.
Attaching intake and out-take leads to the rcbb capbank would need a full run of cable across its base to furnish sufficient carry capacity across that board, as the printed circuit has no capacity the supply your esc will demand.
^^ modifying that RCBB/FC capbank is impractical as it would be most shyt when done... not to the standard this build seems to demand !

ergo

ESC==CAPBANK===BATTS


copper Vs composite alloy: conductivity improvements are inconsequential / minimal compared the benefits of premade alloy plug set configurations.
regs

W

[Fella1340]

Hello there, an error on this page made it impossible to reply. Guess it's working again! I have no issue with scrapping the rc boat bitz cap bank. What is the best solution, I can custom make whatever you decide is best. I had planned on taking off the 8ga on the banks and tieing it inline like I saw with the etti banks. Not having them apart yet I didn't realize this wouldn't work properly. I must be a pain in the ass with all this but your stuck with me till I get this sorted out with the best option available to make the system work optimally. Help a lost Canadian find his way! Thanks for all your help, it's very much appreciated.
Jeff

[drwayne]

Hi
The SF300 are good for ~400A peaks...
The photo below was mid build the cap bank I use for 12S1P SF300 to Castle 2028
The board is a shelf item .. without copper dots or rails.. doubled up to offer more rigidity.
Each capacitor is 63V1000uf low esr .. and this board has 16 of them.
2 joined in series is a series pair..there are 8 series pairs joined in parallel.
The picture should explain what that means :lol:

Hope this helps



113710

113711

[Fella1340]

That's quite the creature you are building. I am going to order some capacitors/ boards up and make something up. Thanks Doc.

[Fella1340]

I finally stripped the heat shrink off the rcboatbitz cap bank. Very surprised to find out its a fightercat board! Strange. These were the same boards I was going to buy earlier and put my own caps on. Does this mean all those hv cats runing around with these are wasting there time?
what am I going to build that will work so much better? I don't know if I am ready to step up to the level you are going doc but want something that works. We have an awful version of radio shack here In Canada. The boards they had there were similar to the fighter cat version. I need a little hand holding here. The wheels are turning but nothing is clicking into place. Help me understand what I need to do. I very much enjoy photos! The bottom of the board is copper full width for each side if that matters. Better than I could have got at the store. Somewhere online to buy what I need? Help!!

[Fella1340]

Perhaps a more compact way of doing it. What is castle or etti doing so different than what I have?
Running a 6"-8" long set of series/parallel. Would be hard to make work. This is a sport boat and much effort is going into appearance as well. I'm missing something here bigtime!
Jeff

[drwayne]

Filtering out voltage spikes / drops or buffering the power supply so there is a constant high voltage available to esc ?
The standard parallel cap banks do both reasonably well.
The circuit I use does same but with 8x the speed of release and recharge.
End of day your power requirements will profile what extras you need.

[Fella1340]

Thanks, I am going to map out what space I have and see what I can fit.

[mekzoid]

Hi again,
I have looked through all the pages and couldn't find my answer.
I am adding the cap bank onto a swordfish 300 running 2x 4s lipos
Could someone please do a diagram on how to solder this up.
Do both negatives and positives coming from the esc need to go through the cap bank?

Thanks guys, New to all this hv stuff

[drwayne]

2x 4S is not HV mate !

if 4S (16V ) is your max voltage, then the optimal bank will not be suitable higher voltages
give me a ring, Im in SAdelaide X414794022

Wayne

[mekzoid]

29.6v is max (2x4s) voltage, Unless you are meant to run a cap bank for each battery individually?

cant call mate, waiting for telstra to send me out my s5 haha

[drwayne]

all good.. you are running 2x4S as 8S
it read 4S2P to me . lol
what type of loading ?
motor, hull and prop ??
W

[Fella1340]

Good day Doctor,
Looks like I know to much now. I either should be shot or do this job correctly! If I run up to 12s and end up staying there will 50volt caps be enough. What should I a at for total uf? I would like to try the series/parallel arrangement. Space is a big factor, is good performance actually available in a smaller package? This has been the last thing I think of and the first thing when going to and getting up from bed! It plagues my dreams! So the correct approach is the only option. If you could advise on cap voltage and total uf for a series/parallel bank with attempting to keep it small I will be in your debt.Armed with these numbers I should be good to go. Yes, I keep coming back and will continue to till its done properly.
Thank-you,
Jeff

[drwayne]

Ok.
Boat usage.. you still have this overweight P1 replica on 10S2P sf300 ?

What was your final motor and Kv choice ???

Do you intend to run this hard at 100% .. or more a play thing ????

[Fella1340]

Sorry about disappearing, life gets busy. The boat will be run on 10s2p and 12s2p through a sf 300 tp5660 820kv, 6 wye. It's certainly not in race trim weight wise but it should par up with similar
Sized boats. I do intend to eventually run it hard. Initially I will spent the time setting it set up. I don't need to perform hard hole shots but I do Want to see how far It can go. 14s may even be an option.
Spending the time initially setting up and running the boat should give me an idea on amp draw and if it's worth pushing. It's an unknown how this hull react to speed. An upgrade in motor will likely happen this summer. You mentioned the castle 2028, I noticed it's only good on paper to 35000rpm. I am curious as to why you recommend it?. I just wanted to say thanks again for the past and to come spoon feeding session. I saw your friends fantasm running a shared cap bank. That had five caps in it, would something like a three behind, two infront arrangement work? I am just thawing out from a long Canadian winter so go easy on me, that and the bucket full of pain medication from back surgery makes decisions that can be very expensive not done correctly best left to others!:-) I should be ready in a week, two at tops and want to get things on order. Thanks again
Jeff

[mekzoid]

Sorry mate totally forgot about this.
will be running a cheetah, swordfish 300, tp5660, Prather 245 or 240. Will spike just above 320amps I think

Thanks for your help

[drwayne]

Sorry for delay, remembered I have a career ... !

fella 1340..
1) friend's fantasm .. which one ?
2) if you have no hole shots planned, the power expectation of circuit is reduced..10S 12S 14S is nice to know, but the total amp draw is the circuit crusher.

I have logged the SF300 to 12S 455amps in peak draw.... =22750W ... your 14000 is quite conservative.
^^ Castle 2028, SF300, 12S1P(12S50/100C5800mAh →29KW avail from packs on peak ), Voodoo 6719/3 !!
Always plan ahead.. expect the unexpected overkill amp draw and if that ever occurs the system will survive to play another day.

5000→6000uf in standard parallel ( as pic below ) is fair for systems not under extreme load.

114445


If your system is borderline barbeque material, the dual parallel+series array cap banks as detailed originally are more your needs..
With this circuit, the refresh and supply is paramount concern, not the total size of the ripple buffer...
ergo power available on GO, not just ripple reduction..
I aim for 2000→3000uf is this situation ( maths for this are on first page.. or PM for help ! )

114446

[Fella1340]

Thanks Doc, I think I can at least make an attempt from here. I think I will end up abusing the boat, increasing kv and motor size so I will go with option two. See if I can't put something together from here. Thanks again,
Jeff

[kevinpratt823]

I have a decent understanding of caps and theory, but bear with me if I might revisit some of your explanations I may not have understood....
In the SprintCat I just built, there is limited real estate that presents a slight challenge. My motor(1527/1Y) is in front, with the ESC(SF240 HV) right next to it, keeping motor leads as short as possible. Long battery wires were kind of unavoidable to the 6s2p/5000 arrangement of (2) 3s in each sponson, and I have little room to install the ETTI 63v/5000uf bank that I had on hand, so I tapped off the ESC leads with 12awg and ran about 14" of wire(the blue/black wires) to get around the motor into the opposite sponson. I could probably make it fit under the ESC shelf, but I was trying to avoid putting any more extra weight on one side along with the servo and ESC. Can you elaborate on the effects of excessive length taps to the bank? Am I causing problems, or just lessening the effectiveness of the caps?
116306116305

[properchopper]

Seems that single motor cats have this problem of connecting two packs that live in the sponson(s) to a central ESC which can require some long runs [and caps]. I've built a few ; my personal Cheetah has some long wires and an Etti cap board from the CC240 to the motor- so far all is well

116317116318

I'm building one now for a customer with a Swordy 220A and came up with a somewhat "shorter-wire" config minus caps.

[Fella1340]

Nice work properchopper. You give me hope I can do it neatly!

[kevinpratt823]

http://img.tapatalk.com/d/14/06/07/amesy6yd.jpghttp://img.tapatalk.com/d/14/06/07/3usaqa9e.jpg
Hello.
The sprintcat cowls have enough 'breathing' space to mount the ESC on top the motor
and it appears you packs are facing towards the transom.. turn them around !

116307

116308
Actually, it's (2) 3s packs end to end. The parallel adapters are a bit long to accomodate the even shorter leads of my other set of TP packs. I really wanted the packs in the sponsons, but with the top deck opening coming in past the tunnel in a sprintcat, the largest packs you can fit in without a shoehorn are 3s/5000. I can fit in 4s packs with some real squeezing, as I want the option of running 8s2p for kicks once I get the boat trimmed up. Next time out, I will try running them standing on end side by side, it may be a better option, and once I figure this stuff out, I will also likely shorten the series connecting leads. I have thought about fabricating something to mount the ESC over the motor, and that will gain me an inch or so, I just want to make sure it doesn't limit my clearance to run the classic hatch forward or backwards. Aside from all that, for my/our own education, would you mind elaborating on the effect of longer tap wires to the ESC?
I am also wondering what you think about the possibility of just running say 2 of these cap banks in series, would that achieve the same results as far as faster charge/recovery rate that you are aiming for with some of your series/parallel setups? Sorry for all the questions, but you are apparently a great resource on this topic.......

[kevinpratt823]

As far as something like a SF300 with 2 sets of batt leads that have to be joined, I am curious what you think of the way I did it. I ran a #12 from one esc batt lead, straight through the bank and back to the other esc batt lead. The connection between the 2 esc leads serves mostly just to equalize the voltage I believe, and I now basically have a set of paralell #12 to feed the cap bank. It's been working great for me, but by all means I welcome your input......116344116346116347

[kevinpratt823]

http://img.tapatalk.com/d/14/06/07/9yjezyta.jpgI will rework the layout in the Sprincat. I am well schooled in electrical theory(above average electrician), and I understand capacitors and inductance, what they do, how they add up in series/parallel, etc... just not to the level of detail of some of the effects/side effects of different arrangements and applications like PWM as you obviously do. For my own knowledge can you tell me the problem of having the tap wires too long to the caps....... Obviously there is a little more resistance, just wondering if there is anything else, and how big a deal it is.

I think you understood the SF300 wiring, but here is a diagram. Yes, the wire that passes through the cap bank unbroken is also the conjoiner, and FWIW the wires are equal length in reality, and the I am feeding each set of independent Fets with it's own 10s1p supply, with the capacitor lead also serving to join the two and equalize the voltage. It runs form one +, across the cap bank(unbroken), back to the other +.

That is a nice piece of work you've got there with the dual output shafts!
I still have some to learn about monitoring and correcting ripple current, as well as what is too high, and what is good or acceptable, but I do love data logging! I have always been intrigued with electrical theory and understand it well, but a lot of this branches into electronics as opposed to my work application, so I haven't delved into it as deeply in the past. Thank you for your time and attention.

[kevinpratt823]

I also am a bit of a Geek when it comes to this stuff, so I will continue to entertain these discussions with the hopes of elevating my knowledge, until you feel that I'm taking away from the thread, so feel free to stop me.........
How could one of the sets of fets possibly see a dropped voltage from one set of packs when the feeding wires are essentially common via the loop that just happens to also pass through the cap bank? The 2 sets of packs, as well as the esc wires, are essentially parallel, they just happen to have a few inches of wire doing the job, instead of bringing the 2 directly together. Even if one side drops, the total voltage the esc sees on each set of fets should be the same aside from a minute voltage drop across said wire, even as one pack "charges" the other pack to recovery, no? In your picture of the sf300, you have the pairs of #8 coming together before the cap bank, and what appears to be single #8 running through from there. My parallel #12's are not that far off from a single #8 in terms of resistance/ampacity I don't think, assuming the ripple and discharges are relatively even between the 2 sets of fets. Mine just happens to have a little more resistance because of the few extra inches of conductor. In the case of the SF300, I really don't see a benefit of bringing the 2 esc wires down to one when they are going to split back to 2 to feed a 10s2p setup anyway.

I thought the firing of the fets was based on the signal from RX, I didn't know the voltage would play a part anyway other than affecting the output, but then again, my understanding of PWM is mostly based on inquiring to a startup rep for large Variable Frequency Drives. I'd love to see you start a thread explaining the ins and outs of fets and the sequences of PWM as it applies to our uses.........
I certainly will be considering all of this stuff, but in the end I am not at the level where this stuff becomes as critical to my sport applications, I have barely broken 70mph as of now, but I still want to learn. I am also not at a point where I want to completely fabricate cap banks like these impressive systems you are displaying, for now I'm just looking for better ways to install what I can readily get to work with. Thank you for giving me food for thought. In a nutshell I will do my best to lower the resistance to my cap banks(and everything else of course) and allow for the highest ampacity as well now that I am more aware of the importance.

[kevinpratt823]

Thanks Doc. I had considered those potential failures when I did this, but I think when I took into consideration that I wouldn't be drawing much over 200 amps and I just wanted the boat in the water I went for it. I will reconsider and put it on my list of weekend morning hobby projects. The smelly, smokey learning curve is still just beginning to level off for me.

[ray schrauwen]

Every time I start reading in this thread I get overwhelmed and almost throw up. I'd love to build one of those cap banks but, it's not going to fit under the cowl of my Whiplash 40.
So Dr. Wayne is it true you deigned or had some part in designing the SF esc's??

I almost cooked one at the nats, tough esc. I added more cooling and I have one of those smaller Etti Cap Banks for LV or at least up to 35Vdc. I only run 6S2P in my Whip.

I'm hoping the cap bank I bought will help some??

[drwayne]

I do think it's time this line of postings was audited for content.
Lots of not really relevant stuff now floods this area.

Ray
240HV and 120LV had fingers like mine through them in earlier days, yes.
Still beta dabbling with new, and twisting through code for performance/longevity updates..

What esc had you almost toasted but then resurrected ?

[kevinpratt823]

Kevin .. Ive been ruminating over this for 10 days. ... lol
What is ampacity.. do you mean amperage ?

Ampacity is the amount of current something is rated to withstand.
"The ampacity of a #12 thhn copper conductor is 25 amps" (but it can only be fused at 20 per electrical code)
Think "amperage capacity"
Sent from my SCH-I535 using Tapatalk 2

[ray schrauwen]

I almost toasted a new SF200 8S esc in my Whip 40 Sport Hydro on 6S2P. I have yet to load test it again but, it's fine on the bench.

It has gotten up to 175F at least on one run, the caps appear to be fine physically so hopefully it still works when I run it again soon. Added an extra cooling plate and the Etti LV cap bank.



I do think it's time this line of postings was audited for content.
Lots of not really relevant stuff now floods this area.

Ray
240HV and 120LV had fingers like mine through them in earlier days, yes.
Still beta dabbling with new, and twisting through code for performance/longevity updates..

What esc had you almost toasted but then resurrected ?

[kevinpratt823]

Wow. :shock:
proof positive I dont know everything !
hahaha

Shhh ... If you spread that admission around I will never hear the end of it :lol:

I now understand 'ampacity' in domestic ac circuits.. mainline 110AC for eg.
However an ac cable suitable to power my 2500W toaster oven on 110AC ( 22.7A) with length of say 6' from the power socket.. would over heat and melt on 25VDC at same 22.7Amp .( just 567W )... :sad:
Automotive headlight cables are minimum 5mm (1/5 of 1") to meet approval in Australia .. else they melt.. for a maximum 150 W globe ...

I see from here that the listed 6AWG(AC) of 4.11mm diam is much smaller than the AWG6 of 6.61mm diam used in our DC circuits.
LOL now that's confusing !!!
http://www.keywolf.com/American_Wire_Gauge.php

Ive a little book that determines wattage capacity for DC cables based on wire diameter, number of strands, quality of copper, quality of insulation and voltage through the wire.
it's 11pm here Wed night .. I will search Thursday daytime for online the same details.
regs
W
As far as I know, Doc, AWG refers only to the total circular mil area of the conductor and is the same for all conductors, AC or DC. The diameter in the chart could be for a single solid conductor or one of fewer strands than the one you referenced. A multi stranded conductor like we use in boating will have a larger physical diameter because of the air gaps between strands, but still has the same cross section of copper. Even with AC wiring, some wire strippers will recommend for example to use the 12 AWG hole to strip 14 AWG stranded. Also, the ampacity of a conductor is primarily limited by heat, so while the #10 with common THHN(90 deg C) insulation that we use in buildings that has an ampacity of 35 amps(but only to be fused at 30), can be bought with much higher temp insulation which gives it a rating of 70 amps. Not sure how that applies to DC, but most of the wire we are using in boats is rated for very high temps, I'll have to look in my code book and see what a 200 deg insulated #10 is good for....
Acceptable voltage drop in my world is typically figured as a percentage of the voltage, so yes, you have far less room for loss with lower voltages, as the resistance is still the same per foot regaurdless of the voltage applied.

For the sake of discussion, in the case of your toaster, the heating element is really just a pure resistor. The 2500 watts is what it is rated to consume at 110v, making it essentially a 4.85 ohm resistor, pulling 22.7 amps at 110v. If you only apply 25v, it's only going to draw 5.15 amps, and you aren't making much toast at 128 watts:sad:, never mind melting the wires.


So, in your hypothetical situation, I think if the wire only carried a fixed 22.7 amps, it likely wouldn't heat up any more at 25v DC than at 110v AC, could you explain to me why you are saying otherwise? Amps are amps, and unless the current increases over 22.7 to compensate for voltage drop while trying to still supply a fixed wattage load, I don't see why it would heat up any more. I am vaguely familiar with the "I squared R losses". iI's been a long time since I've been in a theory class and it's not something that regularly applies to my work, but voltage is not part of that equation. If current is still 22.7, the I squared R loss is the same regaurdless of voltage.

In my work, most of our wire insulation is rated for 600v, the ampacity ratings do not change weather it's 24v or 480v, and I didn't think it changed for AC or DC either, but I don't deal with much big DC. Looks like I'll be flipping though the code book tomorrow. I am not familiar with ratings of "wattage capacity for DC cables", I am interested to understand more....
BTW, that sounds like a serious toaster!

[gtrcguru]

As far as I know, Doc, AWG refers only to the total circular mil area of the conductor and is the same for all conductors, AC or DC. The diameter in the chart is likely for a single solid conductor or one of fewer strands, which would have a larger diameter. A multi stranded conductor like we use in boating will have a larger diameter because of the air gaps between strands, but still has the same cross section of copper. Even with AC wiring, some wire strippers will recommend for example to use the 12 AWG hole to strip 14 AWG stranded. Also, the ampacity of a conductor is primarily limited by heat, so while the #10 with common THHN(90 deg C) insulation that we use in buildings that has an ampacity of 35 amps(but only to be fused at 30), can be bought with much higher temp insulation which gives it a rating of 70 amps. Most of the wire we are using in boats is rated for very high temps, I'll have to look in my code book and see what a 200 deg insulated #10 is good for....
Acceptable voltage drop is typically figured as a percentage of the voltage, so yes, you have far less room for loss with lower voltages, as the resistance is still the same per foot regaurdless of the voltage applied.

For the sake of discussion, in the case of your toaster, the heating element is really just a pure resistor. The 2500 watts is what it is rated to consume at 110v, making it essentially a 4.85 ohm resistor, pulling 22.7 amps at 110v. If you only apply 25v, it's only going to draw 5.15 amps, and you aren't making much toast at 128 watts, never mind melting the wires.
But, in your hypothetical situation, I thought if the wire only carried a fixed 22.7 amps, it likely wouldn't heat up any more at 25v DC than at 110v AC, could you explain to me why you are saying otherwise? I am familiar with the term "I sqared R losses", but it's been a long time since I've been in a theory class, and it's not something that regularly applies to my work, please refresh my memory, is it strictly a DC thing? I am not familiar with ratings of "wattage capacity for DC cables", I am interested to understand more....
In my work, most of our wire insulation is rated for 600v, the ampacity ratings do not change weather it's 24v or 480v, and I did't think it changed for AC or DC either, but I don't deal with much big DC. Looks like I'll be flipping though the code book tomorrow.
BTW, that sounds like a serious toaster!

+1

http://www.southwire.com/support/voltage-drop-calculator.htm

[drwayne]

+1

http://www.southwire.com/support/voltage-drop-calculator.htm

AC relevance only without further reference to cable lengths, current loadings etc.
But it does give a nice dimension of cable rating
But the pvc insulation is not for us .

[NativePaul]

Diddely squat? I have heard that electrons migrate to the circumference of the wires so multiple smaller strands are better than a single bar as it has more circumference per square mm, but is that only true of high voltages and AC currents?

[kevinpratt823]

Diddely squat? I have heard that electrons migrate to the circumference of the wires so multiple smaller strands are better than a single bar as it has more circumference per square mm, but is that only true of high voltages and AC currents?
This is true, and it's referred to as "skin effect", and applies far more to AC. It allows for a VERY slightly lower resistance value to be used for voltage drop in AC vs. DC(your talking a few hundredths of an ohm difference in 1000' I believe in smaller size wires). In higher voltage and higher frequencies it becomes more prevalent, as the back voltage induced in the center of the conductor which forces the electrons out is greater.

Amps are still amps for all intents and purpose. The standard ampacity ratings of the AWG are conservative to begin with, and the ratings for 6' appliance cords is slightly more lenient but should have it as at least a #12. The only other benefit to the larger surface area of multi-strand conductors that I am aware of other than flexibility is heat dissipation, but it still isn't nearly enough to assume that a 6' cord, (which is already a multi-strand for flexibility), would all of a sudden melt because the amps were DC. FWIW, with AC, a 22.7 amp reading is kind of an average(.707) of what the peak amperage actually is, that current is actually peaking at over 32 amps at the top and bottom of the sine wave(same goes for the voltage). You do not need special wire to achieve the same ampacity rating just because it is DC, especially in a purely resistive circuit. The only difference will be that the voltage drop becomes more significant(at lower voltages), but that is not what the discussion is about. For example, I ran the 12v dc winch motor on my old driveway snow plow on the same #10 THHN I use in buildings, well over 6' long, through my(hot) engine compartment. I repeatedly lifted and dropped that plow back to back, drawing well over 35 amps, for hours at a time, and it was perfectly fine. Granted, it's not a continuous load, but the current was definitely higher than the rating of the wire. The 7' leads on the cheap 12v/10 amp car battery charger in my garage are 16 gauge and look like a cord on a cheap table lamp, and I also just looked at the halogen headlights in my truck, they are a regular 16 gauge wire, I have no idea why Aus. has those specs.
Just because a circuit doesn't achieve maximum efficiency according to one's standards doesn't mean it burns up, sometimes it's just less efficient.

Inductive and capacitive dc theory and circuitry may get complicated, but simple DC theory in a purely resistive circuit is not. All the wire charts for sizing in DC give footages primarily to reduce voltage drop, and for 6' you can easily carry 22.7 amps on a #12 @25v, which is likely what the cord of the toaster would be, with no special strand count or insulation noted and probably even maintain an acceptable voltage drop. There will be a voltage drop and thus a reduced wattage at the load, making it less efficient, but amps are amps(coulombs of electrons being transferred across the open spots in the valence electron ring of the conductor's atoms, just so happens that copper has a lot of open spots). You can get as technical as you want, but the cord would not melt. We may get away with carrying more current, more efficiently, through wires because of the fine multi-strands and high temp insulation, but voltage drop aside, a wire that safely carries a given current of AC will safely carry that same current in DC.

Now some of these factors may become more significant when you are, say, trying to squeeze 300 amps through a #10 in a PWM circuit full of capacitance and inductance with very high frequencies at play, but this is not the case here.

Because I am confident in my knowledge and experience on this one, but respect yours as well, I'm now trying to think of what purely resistive appliance I might have that I can hook up to a fully charged 6 cell lipo as an experiment, unless you have a less than vague reply to back up your original statement.

And as far as doing homework and self learning Doc, you ruminated over the term "ampacity" for 10 days, when all you had to do was google "definition of ampacity". Somebody's slacking in the homework dept........:lol:

[ray schrauwen]

Buuuuttttt, once you solder all those nice individual strands, the current travels only on the exterior as if it were solid, which it is..... for our purposes, yes, no?


Diddely squat? I have heard that electrons migrate to the circumference of the wires so multiple smaller strands are better than a single bar as it has more circumference per square mm, but is that only true of high voltages and AC currents?

[kevinpratt823]

Buuuuttttt, once you solder all those nice individual strands, the current travels only on the exterior as if it were solid, which it is..... for our purposes, yes, no?A valid observation, but nonetheless the circuit still likely benefits a bit along the way as the electrons still travel all the strands then regroup at the connector for another inevitable point of resistance and voltage drop.

And for previous reference, here is a chart that says I can go 8.8' with 20 amps @24V DC on a #12 wire while maintaining a 3% voltage drop, I'm pretty sure the extra 2.7 amps combined with 2.4' less wire isn't going to cause a meltdown.....
http://www.theresourcestore.ca/toolbox-wiring.php

[kevinpratt823]

I'm sorry if it went off on a tangent. I certainly respect your background, but some people take your word as gospel on these matters, with obvious good reason, but you gave an example with a very exaggerated result presented as fact, which IMO presented DC as some kind of black magic that cannot be harnessed by ordinary wire, when in reality it was just a case of inefficiency.
There was no broad leading question really, I asked "could you explain to me why you are saying otherwise?", just an inquiry to a couple statements I believed to be inaccurate coupled with the reasons I believed them inaccurate. It was your replies that were broad leading("keep looking", "that's your homework", etc.). They opened the door for me to share what I think I know and what I found in my "homework"; none of it supported the validity of the original examples, so I was left wondering why they were not clearly elaborated on when challenged.
Forgive me if I am passionate about discussing/debating things that intrigue me.

Re-"I do agree, Fluid.:sad:"
Fluid hasn't posted here, so on first look should I assume that is some kind of passive aggressive implication towards something you are discussing outside of this thread?

Carry on

[drwayne]

Keep this thread on DC application of cap banks ..
I do understand people's frustration paddling through the irrelevant flotsam to find DC electrical safety.
An audit/edit/trim/pruning is in order .........

Adieu !

[Cooper]

Wow , I've been reading over this and a lot of misguided theory,,,, I believe it's safe to say that the bottom line is your batteries and esc signals will be much happier with capacitors. (Rated for correct voltage). And one thing that it seems that is confusing some is that dc and ac current act different in transmission. Best transmission of electrical signal mown to man is gold cable frozen to as close to absolute zero as possible. And only reason for a stranded wire is flexibility. Solid is more efficient. Bottom line is our toys will be more efficient from less restrictions and more direct sourcing. (Reaction source (battery) to transmission of work (motor) and I firmly believe capacitors are not necessary for all applications but for what most are dealing with here they become a necessity for longevity of your equipment. This is a pretty good and educational thread :)

[drwayne]

Thanks Cooper

Skin effect re current transfer
Skin depth is sqrt((resistivity of conductor)/(pi*frequency*magnetic permeability of conductor*permeability of free space))
For our Brushless esc/motor loadings of >4S of 2200Kv, that skin effect is <0.12mm due high freq of draw.
Single strand copper conductor do not translate same current as multistrand same cross section when at high frequency.....
more skin = more transfer

that calculation is irrelevant under 22.126KHz in pure copper ... from where conductivity is almost static over solid or multi stranded wire.

Capacitors can reduce/clip most induced frequency prior to power being fed to the esc.. but the flow from battery to caps is where these rules prevail.

chuckle..Ive corrected from 'Ray' to 'Jay' in previous post.... apologies.

[kevinpratt823]

The AWG charts do not specify AC/DC, because they apply to both. The only reason you have separate charts for DC is primarily because of more critical voltage drops.
The RMS(root means squared, essentially .707 of the actual peaks on the sine wave) rating of 22.7 amps, creates the same heat as it's DC counterpart at the same reading. Here is one of many discussions I found when I googled "do awg ratings apply to dc?", regarding AC/DC using the same AWG charts
It basically applies directly to the scenario we're discussing.https://answers.yahoo.com/question/index;_ylt=A0LEVy_g1MtTOmAAAs9XNyoA;_ylu=X3oDMTEza WdwOWFmBHNlYwNzcgRwb3MDMQRjb2xvA2JmMQR2dGlkA1ZJUDQ 4OF8x?qid=20090706093115AACP5Hx


As soon as the toaster was shown to be irrelevant, I began speaking of a hypothetical 22.7 amp load. Your original statement that 22.7 amps @25vdc would melt the cord is false, and grossly exaggerated from a real world perspective, and you have failed to prove otherwise.
When challenged on this, you sent us on a wild goose chase about surface area of stranded conductors, but now you are acknowledging that this is only relevant at very high frequency.


Let's cut to the chase then, and go back to the original statement-
"However an ac cable suitable to power my 2500W toaster oven on 110AC ( 22.7A) with length of say 6' from the power socket.. would over heat and melt on 25VDC at same 22.7Amp .( just 567W )... "

In the real world it definitely will not.

If you don't believe me, talk to somebody who wires DC power in marine applications(my father for example). Non critical systems are allowed a 10% voltage drop, and a #12 can be run 20', protected at 25 amps. That is at 12v. That wire does not melt, just more voltage drop.
Go ahead and pull the lever to block me, it won't make the statement any more true. Again, I respect your knowledge and background, and I have an ego too(obviously:blush:), so I can relate, but here is something to lighten things up a bit.......https://www.youtube.com/watch?v=ubIpoPjBUds

[tlandauer]

Hey, The boats I wire go BOTH Over and Under----that is only when something goes wrong! :lol:
Now seriously I have a question: on 10 or 8 ga. wires that come with some ESC, if I were to solder a cap bank onto the wires near the ESC, the stripped insulation spot need to be properly pre-tinned. It takes quite a bit of heat to achieve that, my soldering technique is average to slightly above average, how much risk do I have before damaging any soldering joints up stream and also electronic components. I hold the wire with cold/wet towel---no dripping water to wet the ESC, of course.
I hope my question does not lower the value of this thread. I feel as if my question is like the ugliest house on the block, lol....

[Cooper]

Thanks Cooper

Skin effect re current transfer
Skin depth is sqrt((resistivity of conductor)/(pi*frequency*magnetic permeability of conductor*permeability of free space))
For our Brushless esc/motor loadings of >4S of 2200Kv, that skin effect is <0.12mm due high freq of draw.
Single strand copper conductor do not translate same current as multistrand same cross section when at high frequency.....
more skin = more transfer

that calculation is irrelevant under 22.126KHz in pure copper ... from where conductivity is almost static over solid or multi stranded wire.

Capacitors can reduce/clip most induced frequency prior to power being fed to the esc.. but the flow from battery to caps is where these rules prevail.

chuckle..Ive corrected from 'Ray' to 'Jay' in previous post.... apologies..

I don't like to be the bad guy but your wrong on the skin effect. I was assuming you would realize the discrepancy in solid 10g wire vs multi strand. It has nothing to do with the space between the strands, skin effect is rather specific to size and frequency. It's the relationship of a signal and percentage of it through the cross section of a conductor. Some specific uses would be a cardboard tube clad in copper would carry a better signal than any multi strand wire at a very specific diameter and frequency. And a lot of times even engineers think multi strand wire is more conductive of electrons (as we are talking of current not signal pwk) than solid conductor. It's one of those real world applications and manufacturing curves that has to be acknowledged. It is impractical to use solid wire by means of installation and by non conforming, non flexible. If solid is bent that location will not be as conductive, kinda like when you bend a tin can it becomes weaker at that stress point. So to keep it relevant the more skin= more transfer is just not the case. Think of it like these battery to motor electrons are rather stupid, they don't know to assemble into anything resembling a sine, just do a flat out sprint to the finish.

[kevinpratt823]

Regardless, the heat generated by 22.7 amps is the same whether its 480vac, 110vac, 25vdc, or even 12dc, that is why the charts don't specify voltage. The heat resistance is not going to run away exponentially in this circumstance, maybe at a far higher current, or a much smaller wire, but not here. The wire is not going to melt. The wire was rated to withstand the current and heat safely regardless of voltage, it would barely get warm in the first place, that is why it is rated(by the US coast guard) to be run 20' and carry 25 amps in marine application, it is being done in the real world on a regular basis. The ratings are all more than conservative, and I deal with conductors working at their ampacity limit on a regular basis. When within the ratings, they barely get warm, there will be no thermal runaway, there will not be enough heat to begin the cycle. Thermal runaway doesn't happen until you are WAY out of the suggested ratings etc. It will just warm up to a safe operating temperature and level off there, dissipating the heat of 22.7 amps like it is rated to do. That is why when wires are confined in a pipe, grouped together, there are de-rating factors, you upsize the conductors to account for the lack of the ability to dissipate heat. In this case, the wire is presumed to be in open air, at ambient temperature, dissipating the heat like it is rated to do.

Do you actually run the branch circuit wires for these boats at work, or do you just build circuit boards and components? I ask because you weren't even familiar with the term "ampacity" 2 days ago, a term that is common vocabulary for most people who concern themselves with appropriate conductor sizes, and it didn't even occur to you that wires with different strand counts would have different diameters, which is irrelevant to AWG sizes anyway.

You also mentioned that I couldn't run 2400 watts on #12 for more than 33'. I have temporary power wiring on my job right now maxing out 20 amp/120v circuits for extended periods running well over 100'(that's 200' if you're counting the return). I know there is significant inefficiency, but the lights are on, tools are working, and nothing bad happens. I also have 15 runs of (5) 400w metal halide lights on 120v, well over 100' to the first, and another 100' to the last, that's 2000 watts, they have been lit on 3 huge floors for 6 months, the wire looks brand new........

Thanks for making me do the research to back up what I thought I knew though. I will point out one mistake I made that maybe nobody picked up on, now that you bring up heat resistance. When I gave the example of your toaster actually being hooked up to 25vdc, I calculated the resistance based on the current at 110v, and used that at 25vdc, but this would not be the case. The toaster,(much like you're describing the wire) may be somewhat of a non linear load. It will probably read as a dead short if you put an ohmmeter on it, the resistance is created when the element heats up after the voltage is applied, so I think the resistance would change at a different voltage.



Sent from my SCH-I535 using Tapatalk 2

[drwayne]

.

I don't like to be the bad guy but your wrong on the skin effect. I was assuming you would realize the discrepancy in solid 10g wire vs multi strand. It has nothing to do with the space between the strands, skin effect is rather specific to size and frequency. It's the relationship of a signal and percentage of it through the cross section of a conductor. Some specific uses would be a cardboard tube clad in copper would carry a better signal than any multi strand wire at a very specific diameter and frequency. And a lot of times even engineers think multi strand wire is more conductive of electrons (as we are talking of current not signal pwk) than solid conductor. It's one of those real world applications and manufacturing curves that has to be acknowledged. It is impractical to use solid wire by means of installation and by non conforming, non flexible. If solid is bent that location will not be as conductive, kinda like when you bend a tin can it becomes weaker at that stress point. So to keep it relevant the more skin= more transfer is just not the case. Think of it like these battery to motor electrons are rather stupid, they don't know to assemble into anything resembling a sine, just do a flat out sprint to the finish.

Correct.
It is based upon total surface area .. ergo your 'cardboard tube surrounded by copper' has larger surface area.
Read my words again.
Thanks

[drwayne]

Hey, The boats I wire go BOTH Over and Under----that is only when something goes wrong! :lol:
Now seriously I have a question: on 10 or 8 ga. wires that come with some ESC, if I were to solder a cap bank onto the wires near the ESC, the stripped insulation spot need to be properly pre-tinned. It takes quite a bit of heat to achieve that, my soldering technique is average to slightly above average, how much risk do I have before damaging any soldering joints up stream and also electronic components. I hold the wire with cold/wet towel---no dripping water to wet the ESC, of course.
I hope my question does not lower the value of this thread. I feel as if my question is like the ugliest house on the block, lol....

I use 120W(240VAC) copper blade solder iron with large tip when 'gluing' large cables ..the heat held within the large tip prevents the need for extended heating to perform the task ... I assume your cap wires are entwined within esc cable.. put some solder to solder tip before you touch the cable.. it will penetrate quickly and then some additional maybe needed to fill the strands ..a few moments is quite fine. Pause between each solder point to allow the cabe to cool..residual latent heat will progress quickly through the cable.
Wet cloth ?..nope ..use a broad grip pliers to hold the wire ..the quick heat and solder technique above is fine.
A wet cloth would 'flash' heat the moisture closest the cable and offer no true heat restraint ..

[tlandauer]

Thank you very much!
:beerchug:

[kevinpratt823]

OK, I'm not sure how you figure I have changed wording, outcome, and fact...? In my first post I speculated that the heat generated would be the same, in my last I basically repeated it. A couple posts between I actually gave a link to some answers to the exact same scenario in a purely resistive circuit, which has doesn't have all the extra properties of complex electronics that you are likely used to.
If you missed it, the question in the link was:
"Will 4A at 110v AC lead to a greater temperature rise than 4A at 24v DC in the same wire?"

The answers......
"No, it won't. The heating is caused by the I²R loss of the wire and not the voltage drop. The 4A AC is an RMS (Root Mean Square) value which is the energy equivalent of 4A DC."

"Also, thermal heating is a function of current only, not voltage"

"The temperature rise along the length of a cable depends only on the current it is carrying, the cross-sectional area and the material it is made of."

Or the one that backs up what I said about getting a voltage drop, but not more heat......

"However, with low voltages, it is generally more important to minimize voltage drop: if the cable carrying 4 amps has a resistance of 1 ohm per conductor, then it will be dropping 4V along the length of each conductor. So your 24V DC appliance will only be getting 16 volts! (4 volts are lost in the positive supply and another 4 volts in the negative return.) You might well want to use a thicker cable which will have less voltage drop. But a 110V AC appliance would be getting 102 volts at the far end of the same cable, which is a bit nearer the mark. Either way, the cable will be dissipating 32 watts of heat along its length." (And as I pointed out, our wire was already rated to dissipate the heat produced, the resistance of a 6' run at a safe initial operating temperature is hardly enough to trigger a cycle of thermal runaway)

I'm not sure what you're basing your "heating profile" on, but the above is some of the information that supports what I have spoken of all along. And even if you have some kind of calculated discrepancy, it's not enough to melt the wires.

All of these are perfectly in line with what I have said from the start, and nowhere along the way did I change that, not sure what you are talking about. In a purely resistive circuit, the RMS readings for AC current and voltage are basically interchangeable. In your electronics circuits with capacitors, induced voltages, pulsing, etc., those equations are an evolution of AC theory, just a little more involved. So yes, AC theory is relevant, much of it is actually interchangeable.

You are the one that said you weren't talking about your toaster, now you are hooking it up to 480vac to prove what? The numbers in your irrelevant scenario don't even make sense! When you quadruple the voltage to a resistance you quadruple the current(it wouldn't stay at 22.7) the wires will fail,... really? Isn't that kind of what I was getting at when I said you have to go way out of the ratings for it to fail? I just referenced 480v in terms of it producing the same heat in the wire at the same given amperage......Let me spell it out again though, if you hook the toaster up to 480v, it will draw 99 amps(for a very brief second), that is 47.5kw(not 11kw). Kind of like if you hook it up to 25vdc it will only draw 5.15 amps, we've already covered this, the toaster is irrelevant, your scenario doesn't even make sense, we are talking about a wire, with a given fixed amperage, at 2 different voltages.

This is copied/pasted from your example......"AWG#12 at 110VAC will carry 2400W... for 33' !!!!!!!!"
Did I miss the part where this becomes DC, bravo? Maybe you had a typo.

BTW, I think you misunderstood Cooper, I'm pretty sure he was implying that sometimes the copper tube, when sized correctly, would work better than ANY stranded wire, as in even one with more surface area."cardboard tube clad in copper would carry a better signal than ANY multi strand wire at a very specific diameter and frequency." "more skin= more transfer is just not the case".
Read his words again.

And I did not claim wiring boats as my father's profession, just that he does it. He has retired from the phone company, where he managed the projects and maintenance of the building systems and infrastructure for several large buildings in Boston. But his heart has always been in his and my brother's commercial tuna boats, just so happens he has the background to do a lot of different things(like basically build and wire the boats), but he does still renew his master electrician's license.

BTW, if you've never seen a 900 lb. bluefin Tuna be stopped dead in it's tracks by electricity coursing through the first 150' steele cable line of a harpoon dart, through another 70' of saltwater, back to a ground plate under the boat, it is a sight to behold for any electron aficionado.

As entertaining as this healthy debate has been, you have had a few days now, and still haven't given any solid evidence of your original claim. In fact, judging by the way you switched from skin effect, to thermal runaway, to grasping at straws about heating profile, to bags of horse $hit and irrelevant scenarios like quadrupling voltage and current, I'm still wondering what you based the original statement on to begin with. Feel free to keep picking my comments apart with technicalities, but you have noted nothing substantial enough IMO, to lead me(or probably anybody else reading) to believe the wire would melt, despite everything my own knowledge, experience, and research has told me, so I guess I can just walk away from this. At the end of the day, the #12's to the baitwell in the boat don't melt, my trucks headlights don't melt, the cheap 10 amp car battery charger doesn't melt...........But if I ever stumble across a good 1.1 ohm/567.5watt resistive load, I'll hook it up to a set of 6s2p packs with a 6' extension cord and send you the video, complete with a clock and IR readings, so we know for sure.
Until then, I guess I'll just "agree to disagree".

Feel free to delete all of it, it's your thread. I do feel, though not all relevant to capacitors, there actually is some educational stuff in here between the 2 of us, if you get through our tiresome banter.
Cheers

[drwayne]

I run this thread to offer guidance through "DC Power 1.01(a)" ..not for debates on semantics or country specific nomenclature.... or topics or deviations which detract from my intent to support this hobby through applicable DC theory.

persons who fail to observe that purpose . . . . straight to the naughty corner it'll be from now on.

I had no urge to 'ignore list' anyone from here.. despite some worthy persons suggesting a need ... after 2 pages of repetitive banter I checked one user's profile and found that degrading opinionated haranguing posts are his forte ( excellence )...
bye bye.......

[jj2003]

Would it benefit putting an external cap bank (Etti E041 63V 5000u) on a MGM 40063-3 X2 ESC? It comes already with (4) 63v 1000u capaciter's. Power will be (2) 7s 5000mah 65c in series for 14s with 2 more in parallel for 14s 10,000mah 65c. MGM controllers (2) will be connected to Lehner 3080/5 LK's. Hull is 92" Radtek with possibly 1865/3 blade props'....Any help appreciated :)

120178120179

[drwayne]

Hello.
Those esc have loggers.
Take your your toy for a run and check for voltage drops under load.
Share that info !
Regs W

[drwayne]

jj2003
2x7s in series.. doubled = 14s1000mAh.. assume per esc ?
7s ? odd size.
lmk.

[jj2003]

Exactly. It is odd size. I would like to run 12s and use long pack's but I don't think it's enough for a Lehner 3080/5 LK. 1050kv in D and 607kv in Y.

[drwayne]

Is this for SAW, Oval, or for the shi.tzengiggles thrill ? ..

[jj2003]

Is this for SAW, Oval, or for the shi.tzengiggles thrill ? ..


The shi.tzengiggles thrill ! :cool2: :roflol:

I'll have mucho dinero, big bucks, Grey Nurses, or depending on how new the money is, Gorilla's :beerchug:
invested and I just don't want to blow anything trying to go fast.
I dont race professionally or amatuer but I would like to do a little of both roun-d-round and a few passes at full bore on an outing,
or focus on getting that single high speed pass at one outing and then try some circles another.
It's a hobby and I expect failure at some point, but I don't want to cut myself short if I could have prevented it by adding caps :noidea:
P.S.
Thanks for your thoughts on this, I appreciate your input :thumbup1: