US Patent 7521138 Apparatus and method for hybrid power module systems

A hybrid power module suitable for use in an array of hybrid power modules comprises a fuel cell stack, an energy storage device, charger circuit operable to charge the energy storage device from the fuel cell stack and/or an external power source at approximately a defined voltage; a stack disconnect switch operable to provide and remove an electrical path between the fuel cell stack and a terminal of the power module, and a unidirectional current flow device electrically coupled to provide a unidirectional current path from the charger circuit to the terminal of the power module when forward biased.