Abstract: A rechargeable power pack comprises a housing, an energy storage device received in the housing, and a set of contacts extending from the housing and electrically coupled to the energy storage device to provide an electrical input current to the energy storage device at a first time and an electrical output current from the energy storage device at a second time. The electrical contacts are preferably formed as a set of prongs sized and dimensioned to be received in a standard electrical outlet. The rechargeable power pack may contain a charging circuit, a discharging circuit, and a switch to selectively couple the charging circuit and the discharging circuit between the contacts and the energy storage device. Additional circuitry may be provided for decoupling the charging circuit when either a voltage, temperature, or time has exceeded some predefined value.