Rechargeable Battery , voltage up to 12 V, 7200 mAh, 4 piece(s) per pack Do you need to improve the battery life of your laptop? A laptop without enough power or a power failure won't upset you anymore. A spare laptop battery is useful as a second battery when you are on holiday and you can't connect your device to an electrical outlet, but still want your laptop to be running. Avacom Battery Kit for RBC31 Renovation (4 Pcs) Battery Key Features Alternative Lead (Pb) battery Safe substitute for the original battery Capacity: 7200mAh, voltage: 12V Provides your laptop with power when you're travelling Delivers an improved battery life and allows you to work longer Tip: Frequent use reduces battery life. Please adhere to the instructions on correct handling and charging that can be found in the manual to prevent capacity loss.