Castle Chart

[Steven Vaccaro]

Have you guys surfed this page?

http://www.castlecreations.com/support/documents/neumotors-castle_boat_apps.pdf

[Meniscus]

Good info!

[Flying Scotsman]

Very good info and it was prepared by Brian Buass "The Snowman" :bowdown: and he knows how to destroy an ESC :tongue_smilie:

Douggie

[AntronX]

Looks like large boats are not covered under warranty at all. I like that they recommend running 2P regardless of hull size, to make sure voltage drop will not destroy an ESC. That's what took out one of Hydra 120 HVs i ran with KB45 motor in my big hydro. I have been asking Castle for a while, to start releasing articles and tutorials how to set up a boat properly. They need to release an article written by their engineer about how and why ESC's fail.

[Flying Scotsman]

What is wrong with 1P. The voltage drop will be the same regardless of 1,2,3,4P. The difference is available amps

[Darin Jordan]

The voltage drop will be the same regardless of 1,2,3,4P. The difference is available amps

This isn't accurate... The V will drop less with 2P over 1P... and 3P over 2P... up to a limit, of course...

The difference between 1P and 2P is noticable for the power systems we run...

[Flying Scotsman]

Darin, this makes no sense. Each cell will deplete it's own voltage to what it was charged at. If the cells are not balanced ...problems...and this will increase with multiple cells and you do not have a device on board that will measure each cell's voltage.

Douggie

[Doby]

My Fellow Canadian;

What I think Darin is saying ( I could be wrong) is that with 2 packs in parallel, the controller will see less voltage drop because its sucking power from 2 packs and they will be able to "balance the load" better than a single pack. You would be sucking power from 8 cells vs 4 cells and the 8 would provide a more stable voltage source.

The more cells (packs in parallel), the more stable the overall voltage will be, even if you have some weaker individual cells.

I think :huh:...................................It sounds logical in my little mind:smile: But I have been wrong before.......................:eek:

[ghostofpf1]

Unless I missed it they don't say 1p or 2p.They only suggest that the packs total ampacity be large enough to supply sufficient voltage at anticipated loads.

HTH
Ghost

[TRUCKPULL]

Douggie

You are a little lost here.
If you look at a discharge graph for any cells be it lipo or Sub C.

Example
4S 4500 – 25C
At 32A you would average 14.4 V
At 64A you would average 14 V
At 90A you would average 13.7 V
At 96A you would average 13.3 V

As you can see the voltage under load drops with the amp draw.

If you run a 2P setup the amp draw that each pack sees is cut in half.
Resulting in a higher voltage under load that is put to your motor.

Also only half the stress put on your cells.
If I run a 4S2P set up in my Wip and draw 100Amps each pack only has to deliver 50A
They run a lot cooler and will last a lot longer (more cycles)
If I run it on 4S1P the pack has to deliver 100A to the motor, resulting in a
- Lower motor Voltage,
- Higher battery temperature which turns into higher internal resistance
- Less Voltage under load output.

The biggest loss is in speed of the boat, even with the extra weight.
At 1850KV-- 0.7V = 1295 RPM on the motor = about 3 MPH
Even with my bad driving I will still beat you in a 1 mile race with a 3 MPH advantage
And my cells will still like me.

Larry

[Flying Scotsman]

Looks like large boats are not covered under warranty at all. I like that they recommend running 2P regardless of hull size, to make sure voltage drop will not destroy an ESC. That's what took out one of Hydra 120 HVs i ran with KB45 motor in my big hydro. I have been asking Castle for a while, to start releasing articles and tutorials how to set up a boat properly. They need to release an article written by their engineer about how and why ESC's fail.

This is what I am referring to. A voltage drop should never destroy an ESC.

Douggie

[AntronX]

This is what I am referring to. A voltage drop should never destroy an ESC. Douggie

Yes, too much voltage drop will destroy an ESC. First the capacitors will overheat from too much voltage ripple, then they will leak the electrolite. Once that happens, they can no longer smooth out current ripple spikes. Then FETs short out and you get fireworks. Voltage ripple is more dangerous at controller's maximum continuous current rating.

[Flying Scotsman]

Thank you Antron. What is voltage ripple in regards to capacitors, in a simplistic sense at low voltage?

Douggie

[Darin Jordan]

Douggie,

There is some decent information here on that topic, including a picture of before and after the application of a capacitor: http://en.wikipedia.org/wiki/Ripple_(electrical)

[Flying Scotsman]

Douggie,

There is some decent information here on that topic, including a picture of before and after the application of a capacitor: http://en.wikipedia.org/wiki/Ripple_(electrical)

Thanks Darin and Antron and others for the knowledge. We are always learning, but some old farts need a knock on the head from time to time :doh:

[AndyKunz]

I wish I could take an oscilloscope to everybody and show exactly what is going on.

Ripple destroys caps, but internal impedance of the cells is what causes the droop. This is Ohms Law.

It's actually pretty slick to see the operation.

Andy

[ReddyWatts]

FINALLY, that is great stuff, the kind of info FE has needed for years. Makes it so much easier to decide on your initial setups without the dreaded smoke. This thread needs to be tacked in "Tips and Info for building a Fast Electric Boat !!!" since OSE sells this equipment.

[Bill-SOCAL]

As a side note, I see lots of FE guys who appear to lack a basic grasp of the fundamental of DC electronics. There is a great book worth reading, it is called:

"There Are No Electrons" In a very easy to read format it takes some pretty dry electronic concepts and makes them clear.

Link to Book (http://www.amazon.com/There-Are-Electrons-Electronics-Earthlings/dp/0962781592)

Review (http://findarticles.com/p/articles/mi_m1510/is_n75/ai_12293005)

Take a look, it really is a fun way to get a grasp on the basics of DC circuitry.

[Flying Scotsman]

Douggie

You are a little lost here.
If you look at a discharge graph for any cells be it lipo or Sub C.

Example
4S 4500 – 25C
At 32A you would average 14.4 V
At 64A you would average 14 V
At 90A you would average 13.7 V
At 96A you would average 13.3 V

As you can see the voltage under load drops with the amp draw.

If you run a 2P setup the amp draw that each pack sees is cut in half.
Resulting in a higher voltage under load that is put to your motor.

Also only half the stress put on your cells.
If I run a 4S2P set up in my Wip and draw 100Amps each pack only has to deliver 50A
They run a lot cooler and will last a lot longer (more cycles)
If I run it on 4S1P the pack has to deliver 100A to the motor, resulting in a
- Lower motor Voltage,
- Higher battery temperature which turns into higher internal resistance
- Less Voltage under load output.

The biggest loss is in speed of the boat, even with the extra weight.
At 1850KV-- 0.7V = 1295 RPM on the motor = about 3 MPH
Even with my bad driving I will still beat you in a 1 mile race with a 3 MPH advantage
And my cells will still like me.

Larry

Larry, and all thanks for the great advise. Now Larry what format because my 1P setup will beat your ass on 1/3 rd mile :bounce:

Douggie

[Fluid]

Unless I missed it they don't say 1p or 2p.


Better read the chart again, it clearly states 2P for every setup on the chart. It's in the second column under Cell count. :cool2:



.

[TRUCKPULL]

The chart was writen by Brian B. I beleive.
They are suggustions for race and sport setups so you will not hurt your equipment.
2P is better for your equipment.

Less heat
longer battery life
safer for your ESC's
EYC

Larry

[alvinsmith75]

Looks to me that Castle isn't interested in supporting the FE Racing community.

[Bill-SOCAL]

Looks to me that Castle isn't interested in supporting the FE Racing community.

I wonder if they are very worried about the 100 or so of us out here?? 17 drivers at the NAMBA FE NATS, and I am not sure about IMPBA, did they even have an FE NATS this year?

Point is that the FE racing community is so small I doubt Castle could care less about it. In fact I wonder what percentage of their sales the marine controllers are in the first place. I'll bet a very tiny slice.

Sad fact is there just are not enough of us to really get the attention of too many vendors. I am actually amazed there are as many as we have. But let's face it, even Steven does OSE as a sideline to his real job so it's not like any vendor is getting rich off of the FE community, let alone the tiny percentage of that group that race.

Until we figure out how to grow this segment of the hobby we will continue to suffer the result of being a very small fringe group.

[ghostofpf1]

Better read the chart again, it clearly states 2P for every setup on the chart. It's in the second column under Cell count. :cool2:



.

You're right....thanks....I still think it's an ampacity thing though unless someone can convince me otherwise ie: If the same ampacity could be achieved with a 1P pack it would suffice just as well as a 2p

Ghost

[TRUCKPULL]

You're right....thanks....I still think it's an ampacity thing though unless someone can convince me otherwise ie: If the same ampacity could be achieved with a 1P pack it would suffice just as well as a 2p

Ghost

You are right in a way.
25C - 5000 packs
1C = 5Amps
25C = 125 Amps

If my setup pulls 125Amps and I use a 1P pack, my packs would be toast in about 50cycles

If I use a 2P pack and pull 62.5 Amps from each pack (still 125A to the motor) my packs will last over 300 cycles with out any loss in battery power.

Now if they made a 50C- 5000 pack (that would be a 250 Amp max) I could pull my
125 Amps and still get over 300 cycles.

The trick here is to only pull 1/2 of what a cells "C" rating is, to maintain full power throughout the cells life, and to extend that life.

Also there is still the higher voltage under load with a 2P setup = faster (see my post above, http://forums.offshoreelectrics.com/showpost.php?p=63562&postcount=10 )

Larry

[ghostofpf1]

Only valid if you double the ampacity at the same time....ie: 62.5 amps from a 2500 mah pack is still 25c

Ghost

[TRUCKPULL]

Only valid if you double the ampacity at the same time....ie: 62.5 amps from a 2500 mah pack is still 25c

Ghost

Yes - but would you want to pull 62.5 Amps from a 2500 pack?
Not much run time in that setup.

Larry

[line6]

What do you guys think would be the better setup and why. A 2s2p High kv motor or a 4s1p low kv motor if they both are achieving the same rpm. say 35,000. and the packs are the same 25c 5000mah 2s1p

[AntronX]

What do you guys think would be the better setup and why. A 2s2p High kv motor or a 4s1p low kv motor if they both are achieving the same rpm. say 35,000. and the packs are the same 25c 5000mah 2s1p

4S1P is better. Half the amps of 2S2P but same power. Much easier on the ESC. Would not matter to the packs though, just to the ESC and possibly the motor.

[TRUCKPULL]

What do you guys think would be the better setup and why. A 2s2p High kv motor or a 4s1p low kv motor if they both are achieving the same rpm. say 35,000. and the packs are the same 25c 5000mah 2s1p

It would depend on the size, weight of your boat,
and what you wanted to do with it,
Race, Sport, or a pool toy.

35,000 prop RPM is a rigger setup.
Larry

[Meniscus]

Good discussion guys. Enlightening even.

[raptor347]

Realize I wrote this for castle with the current crop of batteries in mind. When the 50C+ cells get here, 2P will no longer be required to handle the high current. The run time is still nice with 8-10AH worth of capacity.

The chart doesn't cover all possibilities and is based on my personal setups or combos that I have first hand knowlege of. The race combos are exactly that.

And the ripple current is absolutely deadly at low voltages. One of the reasons N2 boats were so hard on escs running NiMHs.

[TRUCKPULL]

Realize I wrote this for castle with the current crop of batteries in mind. When the 50C+ cells get here, 2P will no longer be required to handle the high current. The run time is still nice with 8-10AH worth of capacity.

The chart doesn't cover all possibilities and is based on my personal setups or combos that I have first hand knowlege of. The race combos are exactly that.

And the ripple current is absolutely deadly at low voltages. One of the reasons N2 boats were so hard on escs running NiMHs.


Brian
How much does adding 2 extra caps to the ESC help??

Larry

[raptor347]

I pretty much double what ever the total value of the factory parts. Adding a pair of 470's to the old B125's made them fairly bullet proof for most N2 stuff.

[detox]

What is the minimum discharge rated battery to use with this chart. I see flightpower makes a 4s 4270mah pack with only 18c discharge rate. Would the 18c discharge rate be safe for any 4s2p combo even though the MAH rating would total 8500 when running two of these packs 4s2p?

Here's battery: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXRVT5&P=ML

I know most all 2s2p setups require atleast 25c rating even at 8500mah.


---------------------------

[raptor347]

All my testing has been done with 20C+ cells, mostly 25-30C. The 18C cells will work for the sport setups, but I wouldn't run the race combos on them.

My .02

[Bill-SOCAL]

The chart says it applies to new motors. What if I use an old motor, will that make a difference?

My boat is red, should I take that into account??

Also in the P monos you do not list a large light hull or a small heavy hull? Why not??

Thanks in advance.

[Steven Vaccaro]

I pretty much double what ever the total value of the factory parts. Adding a pair of 470's to the old B125's made them fairly bullet proof for most N2 stuff.


Forgive my ignorance and I'm not questioning your results, but why the heck wouldn't Castle put more caps on? Seems like a simple solution to solve!

[AntronX]

Forgive my ignorance and I'm not questioning your results, but why the heck wouldn't Castle put more caps on? Seems like a simple solution to solve!

Because most of the time caps that are there are good enough. It also cost versus benefit thing.

[Meniscus]

My boat is red, should I take that into account??

Is this question for real? At first I thought I'd post that that was funny, but upon review, I'm wondering if I'm missing something and thought about offending someone. Usually I post half asleep because that is the time that I have to sit down and read the posts.
__________________________________________
Now I don't know if the same principles apply, but I use certain capacitors in analog audio circuits I design and build. What is the objective? Smoothing the waveform or addressing amplitude issues which distort?

I think I'm reading too far into this. :blah:

[Fluid]

Is this question for real? At first I thought I'd post that that was funny, but upon review, I'm wondering if I'm missing something and thought about offending someone...

What you are missing is Bill's sick sense of humor! :rofl:



.

[Bill-SOCAL]

Forgive my ignorance and I'm not questioning your results, but why the heck wouldn't Castle put more caps on? Seems like a simple solution to solve!

$$$

Same reason Pintos burst into flames. Bottom line profit motive

[AndyKunz]

Pintos burst into flames because of a design flaw. Not everything in the world is motivated by money, although the love of it (and getting it easily) has put America into its current predicament.

I'm an engineer, and one of the things you get to learn is that you must always maintain safety as a paramount concern. Sometimes we screw up. Sometimes people do things that aren't part of the foreseen use. Sometimes the standards change, then people judge you retroactively.

I highly doubt that an engineer trying to save a few dollars was the reason for the problem. Remember, it was the engineers who tried to stop the Columbia launch.

Andy

[ReddyWatts]

raptor: Realize I wrote this for castle with the current crop of batteries in mind.

Raptor, thanks for spending the time to make this chart. This type of detailed chart has been needed for a long time. I really like where you recommend a prop to start with. Could you also make a chart for the OSE Feigao motors with CC controllers? It would lower frustrations for the new guys getting into FE and warranty costs for Castle Creations.

Reddy

.

[Bill-SOCAL]

Pintos burst into flames because of a design flaw. Not everything in the world is motivated by money, although the love of it (and getting it easily) has put America into its current predicament.


Not to get totally off topic here, but it was a financially motivated situation. Ford knew of the flaw and chose not to address it to save $11 per unit.


Ford was aware of this design flaw but allegedly refused to pay what was characterized as the minimal expense of a redesign. Instead, it was argued, Ford decided it would be cheaper to pay off possible lawsuits for resulting deaths. Mother Jones magazine obtained the cost-benefit analysis that it said Ford had used to compare the cost of an $11 ($57 today, allowing for inflation) repair against the cost of paying off potential law suits, in what became known as the Ford Pinto memo

Source: http://www.calbaptist.edu/dskubik/pinto.htm

And I am willing to bet that the reason the ESC we see have fewer caps than ideal is to save money.

[D. Newland]

Another possiblity is that Castle doesn't feel they're needed (though our testing may prove otherwise). Caps are a dime a dozen, so I don't think cost is a factor...Especially when you refer back to how small our group is and how many ESC's they supply us.

Castle has a history of thinking marine ESC's don't need things. Just look at how long it took them to come out with factory water cooling.

I still 100% support them, though.

[raptor347]

For the most part, the factory caps are plenty. Most people using them don't push them as hard as I do.

The extra caps are just a little insurance.

[Darin Jordan]

Most people using them don't push them as hard as I do.

Is that code for "most people aren't as fast as you are"??? :cool2:

[raptor347]

Is that code for "most people aren't as fast as you are"??? :cool2:

No. I just like the scent of those electrical charcoal air fresheners.

Besides, John burned up more than I did this season. Of coure he has the problem of running my hand-me-downs. I don't think I've prestressed any of those parts:popcorn2:

I have to scrub the roofbox out with denatured alcohol after every season (and replace the foam).

[ReddyWatts]

Steven, I think it would be good to publish the Castle chart where you sell the Neu motors, with permission of course.