POST HUMIDIFIER FUEL CELL STACK HUMIDIFICATION SYSTEM

A method for controlling the humidity of a fuel cell stack air inlet, a fuel cell system in which the method may be exercised, and a fuel cell system controller adapted to execute the method in a fuel cell system. The method for controlling the humidity includes detecting the humidity of air entering a fuel cell stack air inlet downstream a humidifier, detecting the water level of a water reservoir, and using the detected values to control the humidity of air entering the fuel cell stack by controlling a supply of water from the water reservoir to a spray nozzle downstream the humidifier.