what's your battery setup for EMAXX?

just wondering what you guys are running? do you make your own batteries? is it not worth your time and do you just buy? any place to special order batteries? what are your run times? what charger do you use?

when i purchased my emaxx, the guy had 7cell, GP 3300. works nice when charged, but only lasts 15 min. they may be old. i'm using it with an intellipeak twin pulse charger.