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Old 03-03-2012, 05:51 AM   #6
kyleservicetech
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Originally Posted by g725s View Post
Thanks for the replies about charging and the power supply.

So I get that charging at the 1C rate is best. I will do that for now.

I will use this power supply for now since it can do fine with the 1C rate for one battery.

But a couple more questions....

How many 1300 3S 25C batteries (currently have three Gens Ace) can I do in parallel with my 10amp power supply at the 1C rate?

I'm guessing that I can lower the charge current for multiple batteries in parallel? And how low of a rate can you charge at for a Lipo?

If you've got a 12 VDC supply, the watts output is P=E times I, or 12 times 10, that's 120 watts.

Now, your Gens Ace battery can be charged at say 1C or 1300 milliamperes, that's 1.3 Amps. Again, watts equals volts times amps so W = 3 (cells) times 4.2 Volts per cell times 1.3 Amps. That's 16.38 watts per 3S battery. The efficiency of your chargers is generally something like 80% so that would be 16.38/0.8 or 20.4 watts per battery.

Next, 120 watts divided by 20.4 watts per battery shows you can charge 5 packs at once. Leaving a safety margin, I'd keep it to three or four packs maximum.

If you're doing this with just one charger, you've got the problem of just having one balance cable for those four packs. IMHO, I'd not parallel that many packs. Just because if anything goes wrong, it's going to be expensive. (Not counting the potential fire issue)

DennyV
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