ThinkPad X60 Series 8 Cell High Capacity Battery.Stay unplugged longer. Get twice the capacity of the 4 cell system battery and up to 7.9 hours of battery life on select systems. The ThinkPad X60 Series 8 Cell High Capacity Battery has an extended section on the back edge and fits in the standard ThinkPad X60 Series system battery slot. It can remain in the system when the system is connected to the ThinkPad X6 UltraBase. All-day computing up to 10.5 hours is possible on select systems when the ThinkPad X60 Series 8 Cell High Capacity Battery is combined with the optional ThinkPad X60 Series Extended Life Battery (40Y7005). Up to 10.0 hours is possible when combined with the ThinkPad Advanced Ultrabay Battery (40Y6789) fitted in the ThinkPad X6 UltraBase. Note that the Extended Life Battery cannot be used in or with the ThinkPad X6 UltraBase. A description of the testing and the environment under which the test was performed is available at www.lenovo.com/pc/ww/thinkpad/batterylife. Battery life (and recharge times) depends on many factors including screen brightness, applications, features, power management, battery condition and other user preferences.Features & Benefits:.Original equipment specifications for correct fit and capabilities:.The 8 Cell High Capacity Battery provides a longer computing time than either of the 4 Cell batteries. When installed, its shape (footprint) extends beyond the rear of the ThinkPad X60 Series notebook.Provides up to 7.9 hours battery life.Designed so ThinkPad X60 Series systems still fit in the ThinkPad X6 UltraBase.Over-discharge protection.Backed by a Limited Warranty from Lenovo with renowned Service and Support available from IBM.