The unique ThinkPad X60 Series Extended Life Battery provides up to 2.6 hours battery life. Fitting to the underside of ThinkPad X60 Series notebooks via the ThinkPad X6 UltraBase connector, it keeps you unplugged longer and provides an integrated look and fit when you're on the move. All-day computing up to 10.5 hours is possible when combined with the ThinkPad X60 Series 8 Cell High Capacity Battery (40Y7003) on select systems. Note that the Extended Life Battery cannot be used in or with the ThinkPad X6 UltraBase. The Extended Life Battery can also be used with the ThinkPad X60 Series 4 Cell Enhanced Capacity (40Y7001) and 4 Cell Slim Line (40Y6999) system batteries.