I see some people here are using lipos, so I thought I should share my knowledge about these batteries.
Lipos could be dangerous if treated wrong. Lipos should newer get over 4.2V per cell and never go under 3.7V. you should always keep them in a fire proof place, there is special lipo bags. Even with the new more stable formula that's out now u should be careful.
And also i recommend to put some money in a nice lipo charger it prolongs the battery life alot, i have a iCharger 106B-plus and are very pleased with it, it's for 1 to 6 cell lipos with a heat protection. and it can charge the new 5C 3cells 2.2Ah easily 5C*2.2Ah=11A*12=132W
should charge and balance in 15-20 min.
Maybe little overkill ;D
Respect your lipos there is alot of energy stored in those.