Oneda New Laptop Notebook Battery for ThinkPad E40 E50 SL410 SL410k SL510 Edge E420 E425 E520 E525 L410 L412 L420 L421 L510 L512 L520 T410 T410i T420 T510 T510i T520 W510 W520 [6-cell / 4400mAh/48Wh] Brand: Oneda; Battery type: Li-ion; Voltage: 10.8V; Cells: 6-cell; Actual Capacity: 4400mAh/48Wh; Color: Black. Improve the service guarantee, Satisfaction guaranteed and backed by a one year replacement warranty. Oneda new high-quality batteries, 100% New from Manufacturer. Up to 500 recharge cycles over the life of the battery. Grade A cells ensure fast charges and low power consumption; Built-in circuit protection. Automatic power cut off at high electric current, voltage or temperature ensures safety and extended battery life. The actual operation time will depend on how much electricity is required by the device and how you use it.