Patent ID: 7976997

Claim:
A method of bringing a fuel cell stack ( 151 ) from a particular temperature below the freezing temperature of water to 0° C., characterized by: (a) providing flow of hydrogen ( 179 , 180 ) to the anodes of the fuel cell stack well in excess of the stoichiometric amount for limiting stack current; (b) interconnecting ( 211 , 212 ) electrical output terminals ( 155 , 156 ) of the stack ( 151 ) with an auxiliary power source ( 208 ), thereby to provide additional current through the stack to increase the amount of heat generated in said stack; and (c) after said step (b), providing a flow of air ( 174 , 175 ) to the cathodes of said fuel cell stack, in an amount in excess of the stoichiometric amount for said limiting stack current, for a period of time.