How Do Fuel Cell Electric Vehicles Work Using Hydrogen?

Like all-electric vehicles, fuel cell electric vehicles (FCEVs) use electricity to power an electric motor. In contrast to other electric vehicles, FCEVs produce electricity using a fuel cell powered by hydrogen, rather than drawing electricity from a battery. During the vehicle design process, the vehicle manufacturer defines the power of the vehicle by determining the size of the fuel cell, and the amount of energy to be stored on board by the size of the fuel tank. This is different from an all-electric vehicle, where the amount of power and energy available are both closely related to the battery's size. Learn more about plug-in hybrid electric vehicles.

Key Components of a Hydrogen Fuel Cell Electric Car

Battery (auxiliary): In an electric drive vehicle, the auxiliary battery provides electricity to start the car before the traction battery is engaged and also powers vehicle accessories.
Battery pack: This battery stores energy generated from regenerative braking and provides supplemental power to the electric traction motor.
DC/DC converter: This device converts higher-voltage DC power from the traction battery pack to the lower-voltage DC power needed to run vehicle accessories and recharge the auxiliary battery.
Electric traction motor: Using power from the traction battery pack, this motor drives the vehicle's wheels. Some vehicles use motor generators that perform both the drive and regeneration functions.
Fuel cell stack: An assembly of individual membrane electrodes that use hydrogen and oxygen to produce electricity.
Fuel filler: A filler or "nozzle" used to add fuel to the tank.
Fuel tank (hydrogen): Stores hydrogen gas on board the vehicle until it's needed by the fuel cell.
Power electronics controller: This unit manages the flow of electrical energy delivered by the traction battery, controlling the speed of the electric traction motor and the torque it produces.
Thermal system (cooling): This system maintains a proper operating temperature range of the engine, electric motor, power electronics, and other components.
Transmission: The transmission transfers mechanical power from the engine and/or electric traction motor to drive the wheels.


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