Patent ID: 8492038

Claim:
A method of shutting down a fuel cell assembly having a fuel cell portion, comprising the steps of: (A) reducing an average temperature of the fuel cell portion from an operational temperature to a selected temperature that is lower than an average operating temperature when the fuel cell portion is coupled to an idle primary electrical load; (B) disconnecting the primary electrical load from the fuel cell portion once the selected temperature is reached; (C) terminating air flow to the cathode flow field; (D) connecting an auxiliary electrical load to the fuel cell portion while performing step (C) to thereby reduce a voltage of the fuel cell portion to less than 0.2 volts/cell; (E) providing a flow of a purge gas mixture through the cathode flow field; (F) terminating hydrogen rich fuel flow to the fuel cell portion; (G) providing a flow of a purge gas mixture to the anode flow field; (H) cooling the fuel cell portion to a selected storage temperature; and (I) periodically purging the cathode flow field and the anode flow field with a purge gas mixture while performing step (H) of the shutdown procedure.