US Patent 8343654 Rechargeable battery pack

The invention relates to a rechargeable battery pack. Particularly, but not exclusively, the invention relates to a rechargeable battery pack for a battery powered appliance such as a hand held vacuum cleaner. The rechargeable battery pack includes at least one power interface for transferring power from the battery pack to an appliance during use and a single charger input terminal to which an output terminal of a battery charger is connectable during use for charging the battery pack, wherein the single charger input terminal is connectable to the output terminal of a battery charger when the battery pack is connected to an appliance and when the battery pack is not connected to an appliance.