About The Item: Battery Typebattery Type: Replacement Lithium-ion Battery. Voltage: 22.2v, Capacity: Upgraded 4000mah Oemno Fake High Capacity Label. No Memory Effect, No Pollution, And Low Self-discharge, Can Be Charged Or Discharged As Needed Without Loss Of Capacity. 100% Compatible With Original Charger, Docking Station. Vacuum Cleaner Battery, Vacuum Cleaner Accessories. Compatibilitythe Dyson Battery Part No. 917083-01 Is Comfirmed To Equal To Original Dyson Dc31 Battery. Perfectly Compat.