JYF 57wh 6 Cells Laptop Battery for Lenovo ThinkPad E420 E50 SL410 SL510 T410i T420 T510i T520 W510 W520 Batteries capacity: 5200 mAh | Chemistry: Li-ion | Voltage: 11.1 Volts | Cells: 6 100% New from Manufacturer. Up to 500 recharge cycles over the life of the battery. Fast charging. Low power consumption. Built-in protection circuit ensures both safety and stability. Grade A cells ensure fast charges and low power consumption; Built-in circuit protection ensures both safety and stability. 24 x 7 email support, 12-month hassle-free warranty.