ThinkPad T61/R61 14 Wide 9 Cell High Capacity Battery uses Lithium – Ion technology. It can be used as a replacement for aging system batteries or as a convenient spare battery. Features & Benefits: - Lithium-Ion technology - Nine-cell, rechargeable system battery, 10.8 V DC, 7.8 Ah - Battery performance watt-our 84.24 Wh - Standard system battery specification - Over – discharge protection