Nope, almost all Li-Ion batteries have a max of 800 mAh. Batteries with higher ratings are most probably fakes and far inferior to the XTars and TrustFires.
Racona is talking the "AA" style 14500 li-ion batteries. Which UltraSabers uses exclusively. The Obsidian/Emerald/Diamond cards require the 7.4 volts that the 2 batteries put out. Using ANY other battery/pack would void the warranty.