I have a Corona 120 helicopter that I had just recently converted to use 2 lipo batteries in a Parallel Circuit. Both Lipos are 3 cell 11.1v 2000 mAh each, when the heli is flying with the 2 lipos in parallel circuit, the combined batteries give me 11.1v 4000 mAh and that works great giving me lots more flying time! But I have been charging the batteries one at a time instead of in combo parallel, is it safe to charge them both at the same time using the Parallel circuit wire harness? Would I set my trition charger to 11.1v 3 or maybe 4 amps to charge both at the same time instead of the present charge setting of 11.1v 2amp that I use now to charge them one at a time?

I would charge them seperately. If they are slightly out of balance, one pack will be over charged and one pack undercharged. This difference will increase with every cycle until you damage one or both packs.

Yes, you can do that. Cells are often connected in parallel to provide greater mah. The 2000mah you have now are probably 3s2p. You're simply changing them to 3s4p when you hook them in parallel.

It should not be a problem, even if they are out of balance:

[link=http://www.rcgroups.com/forums/showthread.php?t=360141]http://www.rcgroups.com/forums/showthread.php?t=360141[/link]
[link=http://www.rcgroups.com/forums/showthread.php?t=360273]http://www.rcgroups.com/forums/showthread.php?t=360273[/link]

Lorents

Charge 2 packs at once .
Buy a few pairs of Banana Plugs and make up any type of charging cable(double check your polarity when doing this)

Hobbico 12 Volt DC Quick Field Charger MkII

http://www2.towerhobbies.com/cgi-bin...&I=LXCTZ5&P=ML