An oxyhydrogen vehicle includes an oxyhydrogen generating unit for electrolytically converting an electrolyte into oxyhydrogen gas, a combustible fuel supply unit for storing combustible fuel, an engine unit coupled to the oxyhydrogen generating unit and the combustible fuel supply unit, and an electric power supply system electrically connected to the oxyhydrogen generating unit for providing electric power thereto. The electric power supply system includes: a storage battery; an alternator driven by the engine unit to generate an electrical output, and electrically connected to the storage battery; a current controller electrically connecting the storage battery and the alternator to the oxyhydrogen generating unit for controlling electric current flow to the oxyhydrogen generating unit; and an auxiliary electricity generating unit electrically connected to the storage battery, and driven by renewable energy resources so as to generate an electrical output for charging the storage battery.