Are you a ThinkPad T Series customer who needs an extra Lithium Ion System battery? For extended power needs, you may want to have an extra system battery. The ThinkPad T Series Lithium Ion System Battery is a rechargeable battery that supports the ThinkPad T Series. This battery contains 8 cells providing an output of 10.8V and can be recharged in 2.0 to 5.0(1) hours depending on the ThinkPad system usage. Spare system batteries can be swapped in to maximize unplugged system usage. (1) Results based on BAPCos (Business Applications Performance Corporation) SYSmark benchmark test. Battery life and recharge times will vary based on many factors including screen brightness, applications, features, battery conditioning, power management and other customer preferences.