To provide an electrical system which can regulate the temperature of an auxiliary battery which has not been regulated in the temperature heretofore without accompanying a large cost increase.
In an air duct 700, a cooling fan 406, an opening and closing valve (1) 702 and an opening and closing valve (2) 704 are provided. In the air duct 700, a converter (2) 402 and the auxiliary battery 404 are arranged. One of a state that air is supplied serially to the converter (2) 402 and the auxiliary battery 404, a state that air is supplied in parallel to the converter (2) 402 and the auxiliary 404, and a state that air is supplied to the converter (2) 402 and air supply to the auxiliary battery 404 is interrupted is selected in accordance with states of the opening and closing valve (1) 702 and the opening and closing valve (2) 704.
Toshio Morita
Takao Matsuyama
Tadashi Muto