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.

IMG_0346.jpg

[tlandauer]

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?

[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 02012011220.jpg


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/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?

[QUOTE=tlandauer;447891]

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.

IMG_0175.jpgIMG_0207.jpg

[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 [ATTACH=CONFIG]83340[/ATTACH]


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 ...

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

2.jpg

1.JPG

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

[drwayne]

Here are some details of the shared bank

IMG_0204.jpg

IMG_0202.jpg

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.

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 ...

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 [ATTACH=CONFIG]83356[/ATTACH]


[ATTACH=CONFIG]83357[/ATTACH]

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