A stack current controller may be configured to determine a stack current request based on a state of charge of a battery, an error based on a difference between an actual coolant temperature and a coolant temperature setpoint, or both. A plurality of stack current levels may be implemented corresponding to different battery state-of-charge thresholds. The determined stack current magnitude may be the lowest current magnitude that provides sufficient heat to maintain a coolant temperature at the coolant temperature setpoint or within the coolant temperature threshold. The determined stack current magnitude may be the highest current magnitude that provides sufficient power while maintaining a coolant temperature at the coolant temperature setpoint or within the coolant temperature threshold.

A fuel cell vehicle is mounted with a fuel cell system including a fuel cell stack and a battery. The fuel cell vehicle controls operation of the fuel cell system with an ECU, to perform standby power generation from activation to when travel is allowed and to perform power generation during operation of the fuel cell vehicle after travel has been allowed. In an activation method, the power generation current is increased in accordance with a low-temperature efficiency rate during the power generation during operation, the battery is charged and the power generation current is increased in accordance with a standby current increase rate that is lower than the low-temperature efficiency rate during the standby power generation.

A non-aqueous lithium power storage element that includes a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte, the positive electrode having a positive electrode collector and a positive electrode active material layer that includes active carbon, and the non-aqueous lithium power storage element having configuration (1) and/or (2). (1) The negative electrode includes a negative electrode collector and a negative electrode active material layer (2) The non-aqueous electrolyte contains (A) LiPF.sub.6 and/or LiBF.sub.4, (B) an imide lithium salt, and (C) an oxalate-complex lithium salt, the ratio of the mass of component (C) to the total mass of components (A) and (B) being 1.0-10.0 mass %.

An exemplary fuel cell ship is a fuel cell ship for propelling a hull by using electric power supplied from a fuel cell that generates electric power through an electrochemical reaction of fuel, and includes a compartment including an emission source of the fuel and a first detector arranged in the compartment to detect the fuel. If the first detector detects that a concentration of the fuel in the compartment is equal to or greater than a first threshold value, a power supply to a non-explosion-proof device in the compartment is stopped.

An exemplary fuel cell ship is a fuel cell ship for propelling a hull by using electric power supplied by a fuel cell that generates electric power through an electrochemical reaction of fuel, and includes at least one compartment including an emission source of the fuel, and a vent pipe through which the fuel in the compartment is released to outside of the hull. A release port of the vent pipe is located at a position higher than a cabin or a bridge provided on the hull.

A fuel cell ship includes a storage battery compartment installed with a storage battery that supplies, to a propulsion device, electric power different from electric power by a fuel cell. The storage battery compartment is provided between a deck and a ship bottom portion of a hull.

An exemplary fuel cell ship is a fuel cell ship for propelling a hull by using electric power supplied from a fuel cell that generates electric power through an electrochemical reaction of fuel, and includes a tank compartment installed therein with a fuel tank that stores the fuel. The tank compartment is provided below a deck of the hull and provided separately from other compartments.

A fuel cell ship includes a propulsion device that generates propulsive force on a hull by electric power, an electric power supply unit that supplies the electric power to the propulsion device, and a degradation rate control unit that adjusts a degradation rate. The electric power supply unit includes a plurality of fuel cells that generate electric power by an electrochemical reaction of fuel and at least one storage battery.

A fuel cell system includes fuel cell, an electrical storage device that stores electric power generated by the fuel cell, and a control device that controls generation of power by the fuel cell, that acquires a charging rate of the electrical storage device, when the electric power in the electrical storage device is supplied to external devices, the control device performs first control which increases a charging rate of the electrical storage device and second control which restricts a power generation amount of the fuel cell to be smaller than in the first control and decreases a charging rate of the electrical storage device, and when a temperature detected by the temperature sensor is lower than a predetermined temperature, a power generation amount per hour of the fuel cell in the first control is reduced in comparison when the detected temperature is equal to or greater than the predetermined temperature.

The control device is provided with a power generation part configured to be able to selectively perform normal power generation and low efficiency power generation in which the power generation loss is greater compared with normal power generation when there is a request for warmup of the fuel cell. The power generation part temporarily stops the low efficiency power generation and performs normal power generation when during performance of the low efficiency power generation the target generated electric power of the fuel cell becomes equal to or greater than a predetermined first switching electric power.