Been there, doing that:
http://www.airsoftcanada.com/showthr...ight=rofinator
11.1v @3000mAh makes for very high ROF. I don't know how long my gears will last, but it's a lot of fun.
I was working on a low voltage protection cct, but never got around to it. LIon cells don't like to be deeply discharged or short circuited. Still, if I charge thoroughly before a game, it's hard to see running out 3000mAh with my locap play. I do need to fix the guns semi mode though. It's become double shot which often works fine, but occasionally jams in a way that can only be cleared by switching to full auto.