lipo C rating ?

[stevessti]

I know if you run two batteries in parallel the mAh will double, but will the C rating also double? Please explain. Thanks

[line6]

http://forums.offshoreelectrics.com/...es-or-parallel

this should help you out

[PapaGriz]

No, the C rating does not double. Each pack can still only handle the amp draw specified by the C rating.
A 40C 5000mAh battery will always be limited to a 200 amp draw.
(40 x 5000 mAh) / 1000 = 200 amps

But in a parallel setup each pack only has to supply 1/2 the amp draw. So two of those same batteries in parallel has a 400 amp draw potential.
2 x [(40 x 5000 mAh) / 1000] = 400 amps

Of course, you never want to max out the amp draw on your LiPos.

[stevessti]

so it is always better to run 2 in parallel if the boat can hold the extra weight?
my setup is impulse 31, seaking 180A ESC, leopard 4074,upgraded OSE flexcable,X646 prop,and right now i have 2x venom 50C 5600mAh 2s in series, and was thinking of going with 2x zippy 30C 5800mAh 5s or 2x 30C 5800 4C. dont know if it would be 6 one way 1/2 the other because of the weight with the extra cell?
PS never run wide open for long, pond not that big

[Boaterguy]

yes, but I have been told not to push a 2p setup very high, if you take papa griz's batteries, i would only run them at 300A (although not many esc's can take more than that) because the discharge may not be perfectly even all the time.

[Fluid]

You can push quality 2P packs as much as is prudent - certainly to 75% of the rated continuous discharge is safe....on 5000mAh/40C cells that's 300amps. But as mentioned, few ESCs can handle that level of power for very long so why try? All bets are off on Turnigy and other cheap packs, I've seen them burst into flames at 50% of the maximum continous discharge rating. If one pack discharges faster that isn't a problem unless you discharge below 80% of the cell capacity - a very poor idea.

The biggest problem is knowing what the true "C" rating for a cell is. We know that some Chinese makers inflate the numbers - just like so many cell matchers did with nickel cells a decade ago. With quality cells you know the rating is very close to accurate. With cheap cells, well......




.

.

[Boaterguy]

too bad you can't get a "C" checker, i'm sure it would be easy to run an ammeter and do the calcs.

[line6]

the prob from what i understand is that is just no industry standard to measure "C" rating so one brands 40c is anther brands 50c.

[Boaterguy]

the prob from what i understand is that is just no industry standard to measure "C" rating so one brands 40c is anther brands 50c.

yes, gen's ace 65C packs can outrun maxamps "true" 150C, I guess maximum amps/mah, but how do you get something to draw the max amps out of a pack without exceeding?