The 6 cell thinkpad battery 70 powers your device for the longest possible time compatible with the t4102030 t5102030 w5102030 l41012202130 and l510122030 systems the average run time is 57 watt hours the rechargeable battery utilises lithium ion technology and works with the thinkpad external battery charger 40y7625 battery life differs due to many factors including screen brightness power management features battery conditioning applications and other customer p