Stay unplugged longer with the ThinkPad T400s Series 6 Cell Battery. This rechargeable battery uses Lithium-Ion (Li-Ion) technology and can be used as a replacement for aging system batteries or as a convenient spare battery.
Features & Benefits:
• Lithium-Ion (Li-Ion) technology
• Six-cell, rechargeable system battery, 11.1 V dc, 3.9 Ah
• Standard system battery specifications
• Over-discharge protection