Stay unplugged longer with Lenovo ThinkPad Batteries. The ThinkPad W700 9 Cell Lithium-Ion Battery is a rechargeable battery using Lithium-Ion technology. It can be used as a replacement for aging system batteries or as a convenient spare battery. (For battery life, go to lenovo.com/alldaycomputing)Lithium-Ion (Li-Ion) technology Nine-cell, rechargeable system battery, 10.8 V dc, 7.8 Ah Standard system battery specifications Over-discharge protection