(4x50g59217) Genuine Lenovo 6 Cell Battery 76+ for Thinkpad E Series Models - E550 , E550c, E555, 45N1762, 45N1763, 45N1759, 45N1760, 45N1761 Genuine Lenovo 6 Cell Battery 76+( 4x50g59217) for Thinkpad Models E550, E550c, E555, E560, E565 6 cell system battery, Over-discharge protection to prolong the life of the battery ,Battery energy (Watt-hours): 48Wh Battery life is affected by many factors. These include: screen brightness, power management, battery conditioning, features, applications and other customer preferences. 4x50g52917 battery 76+ , 10.8v , 4.4ah , 6 cell , 48wh system battery