A 2S lipo would be 7.4v, 7.2v is a 6 cell NiMh pac. 6.3v indicates your lipo is not dead, but it should charge to 8.4v when completely charged since a lipo cell charges to 4.2v/cell max. The other thing about lipo you have to worry about is overdischarging them - they can be damaged discharging below 3v/cell or below 6v for a 2S.


This would be a good charger to consider, it is a balanmcing charger for lipo -

http://www.hobbypartz.com/thac6smbachw.html