A fuel cell power plant is provided for a mobile unit. The mobile unit is provided
with a drive device (29) driving the mobile unit when supplied with electrical
power. The power plant comprises a fuel cell (21) generating power when
supplied with fuel, a battery (27) charged with power generated by the fuel
cell, a power regulation device (31) selectively distributing power from
the fuel cell (21) and the battery (27) to the drive device (29),
and a controller (33) for controlling running operations. The controller
(33) estimates the energy required to activate the fuel cell (21),
and controls the power regulation device (31) when the energy required to
activate the fuel cell is greater than or equal to a determination value so that
the fuel cell is not activated and power from the battery (27) is supplied
to the drive device (29).