Power output device with fuel cell and method therefor

An output limitation warning lamp is turned on when a possible output Qf of the fuel cell is less than a predetermined value L2. The output limitation warning lamp is provided at a combination meter in an instrument panel. The output limitation warning lamp is also turned on when a possible output Qb of the secondary battery is less than a predetermined value L3. Furthermore, the output limitation warning lamp is also turned on when an allowable drive output Qh, which is the sum of the possible output Qf of the fuel cell and the possible output Qb of the secondary battery, has been less than a required output Ed* calculated at a step before carrying out output limitation to more than a certain extent for longer than a predetermined length of time.