The thinkpad battery 17 can help to keep your x100e system powered for longer this 6 cell 57 wh 108 vdc 52 ah rechargeable battery uses lithium ion li ion technology and can be used as a replacement for ageing x100e system batteries or as a convenient spare battery the thinkpad battery 17 is compatible with both x100e and x120e notebooks and offers over discharge protection enabling better battery life