Patent ID: 8481220

Claim:
A fuel cell power supply, comprising: a fuel cell; a first DC-DC converter having first and second I/O sections, with the first I/O section connected to an electric load and the second I/O section connected to the fuel cell; a power storage means; and a bidirectional second DC-DC converter having first and second I/O sections, with the first I/O section connected to the electric load and the second I/O section connected to the power storage means, wherein the fuel cell power supply further comprises: a fuel cell voltage detection means which detects a terminal-to-terminal voltage of the fuel cell; a controller programmed to cause a first state by controlling an operation of the first DC-DC converter to stop an output current of the fuel cell and supplying electric power from the power storage means to the electric load via the second DC-DC converter, and to cause a second state by controlling the operation of the first DC-DC converter to adjust the output current of the fuel cell to a first predetermined current value and supplying the electric power from the power storage means to the electric load via the second DC-DC converter; an internal resistance calculator programmed to calculate an internal resistance value of the fuel cell on the basis of a detection voltage of the fuel cell voltage detection means in the first state, a detection voltage of the fuel cell voltage detection means in the second state, and the first predetermined current value; and a deterioration level determination element programmed to determine a deterioration level of the fuel cell on the basis of a change in the internal resistance value of the fuel cell calculated by the internal resistance calculator.