A fuel cell electric vehicle (FCEV) is a vehicle that uses electric energy obtained from hydrogen as a power source, and is often called a hydrogen electric vehicle. Like the BEV, it is powered by an electric motor and emits only pure water instead of exhaust gas. The core component of FCEV is the fuel cell system. Fuel cells use an electrochemical reaction between oxygen and hydrogen to convert chemical energy into electrical energy. FCEVs have high convenience and are considered the ultimate eco-friendly vehicle because the charging time of hydrogen fuel is almost the same as the refueling time of general internal combustion engines.