TP T40/R50 SERIES 9-CELL LION BATT Provides up to one-third more capacity than the standard system battery. This high-capacity battery has an extended area on the back edge and fits in the standard ThinkPad T40/R50 system battery slot. It can be used even when the notebook is connected to the ThinkPad Dock II, Mini-Dock or Port Replicator II. It can be recharged with the optional ThinkPad Multiple Battery Charger II. All-day unplugged computing is possible (up to eight hours on select T40/R50 systems) when the ThinkPad T40/R50 Series 9-Cell Li-Ion Battery is combined with the optional ThinkPad Ultrabay Slim Li-Polymer Battery. Battery life (and also recharge time) will vary depending upon screen brightness, applications used, features installed, power management settings, battery condition and other customer preferences.