METHOD FOR OPERATING A FUEL CELL DEVICE, THE FUEL CELL DEVICE, AND A MOTOR VEHICLE OUTFITTED WITH A FUEL CELL DEVICE

A method for operating a fuel cell device comprising a fuel cell stack having at least one fuel cell, involving the steps; a) drying of the fuel cell stack upon switching off the fuel cell device; b) determining the membrane residual water and the cathode residual water by means of electrochemical impedance spectroscopy when restarting the fuel cell device; c) using a cell voltage monitoring unit to identify the wettest cathode in one of the fuel cells; d) model-based determination of the water transport from the wettest cathode to the anode and thus the anode moisture in the fuel cell device; and; e) adjusting the electric current and the fuel volume flow in dependence on the anode moisture. A fuel cell device and a motor vehicle having a fuel cell device is also provided.