A method for recharging a battery pack (40; 40′) includes attaching a portable charger (120) to a user, which portable charger comprises or is attached to a self-contained power supply (130, 140) and wherein a first charging port (132, 146) of the portable charger is disposed, e.g., on a belt (144) worn by the user, hanging the battery pack on the belt while the battery pack is physically engaged and in electrical communication with a power tool (10; 10′), and initiating a transfer of power from the charger to the battery pack when the first charging port is at least proximal to a second charging port (85, 148) that is in electrical communication with at least one battery cell (50) of the battery pack. A portable charging system capable of performing this method, as well as an adapter for use in performing this method, are also disclosed.