Patent ID: 8361666

Claim:
A fuel cell apparatus comprising: a rechargeable power storage device, a fuel cell unit including a fuel cell having a catalyst, a controller programmed to make a power allocation between the fuel cell unit and the rechargeable power storage device in accordance with a required system power output, and programmed to control charging and discharging of the rechargeable power storage device and power generation of the fuel cell unit, wherein the controller is further programmed to limit variation of an amount of power to be produced by the fuel cell unit, by charging the rechargeable power storage device with an excess of power produced by the fuel cell unit, when a state in which an amount of power allocated to the fuel cell unit is higher than an oxidization-reduction power level of the catalyst and the amount of power to be produced by the fuel cell unit is higher than the oxidization-reduction power level of the catalyst would change to a state in which the amount of power allocated to the fuel cell unit is lower than the oxidization-reduction power level of the catalyst, thereby reducing a chance of an output voltage of the fuel cell unit crossing below an oxidization-reduction potential of the catalyst.