US Patent 7932634 Fuel cell hybrid power supply

A hybrid power supply includes a switching type DC/DC boost type converter that receives energy from a fuel cell and is arranged to deliver the energy to a rechargeable cell, set to provide a fixed output voltage that is less than the full charge voltage of the rechargeable cell. The hybrid power supply includes a circuit including a fuel cell current control that senses fuel cell current, and controls in part operation of the converter to provide constant current discharge on the fuel cell side of the hybrid power supply.