US Patent 7678477 Method of operating a fuel cell stack

A method of operating a fuel cell stack including disconnecting the primary electrical device and purging gas in the cathode reactant gas flow field by flowing air into the cathode reactant gas flow field. Thereafter, the gas in the cathode reactant flow field is purged again by flowing hydrogen into the cathode reactant gas flow field. Gas in the anode reactant gas flow field is purged by flowing air into the anode reactant gas flow field. Thereafter, the anode reactant gas flow field is filled with hydrogen and both the anode and the cathode are stored with hydrogen.