st235

Ok I'm a cheap stake. I have two lipo chargers and both will only do up to three cells. I want to put a larger motor in one of my planes and it calls for five cells. so can i make a pig tail to connect a three cell and a two cell together? I don't have the money to pay a couple hundred dollors for a battery and a couple hundred more for a new charger.
Thanks for any help.

DaveFlynn

Yes, but check the voltage first. If they are within 0.1V of each other, closer is better, plug them together and charge them all at once. 3S10P anyone?

Of course if your charger only puts out 5 amps the connecting 2100 cells more than 3S4P wouldn't save you any time. My charger goes to 5 amps and if I fly 6 packs as 9S2P and reconnect to charge as 6S2P + 3S2P, 2 cycles instead of 6. Saves about 3 hours.

ChopperMike

Also the packs need to of the same type. The individual cells in each pack need to be the exact same type or you'll have problems not only with charging but with discharge as well. In other words, don't try to series charge a 2100 mAh 3 cell and a 1800 mAh 2 cell. And I would definitely make sure to balance charge them.



Mike

st235

ok thanks mike I thought about that.
Dave so you say if i want a 5cell I can plug them together and charge them on my 3cell charger. And when I plug them together is it + to + or + to -? if I want a 6 cell I can't charge them seprate as two 3 cells?

ChopperMike

If your charger is a 3 cell max you'll have to charge the packs separately and then connect them together when you fly. When you connect them together after they're charged, you connect the positive of one pack to the negative of the other and the remaining positive and negative leads are your output to the ESC. Connecting positive to positive and negative to negative (assuming of course like packs) is a parallel connection which will give you the same voltage but twice the capacity.



Miker

st235

Thanks guys. this has been a real help to me. You are very kind. thanks again
Steve