DIRECT CURRENT POWER SUPPLY CIRCUIT MOUNTED IN WORKING VEHICLE

There is provided a direct current power supply circuit mounted in a working vehicle with increased safety as compared with related art by a configuration where a main power source is used after a battery management system (BMS) determines that the main power source can be used. A direct current power supply circuit includes a first power source, a switch, a second power source and a first relay, in which the first power source is connected to a battery management system through the first relay so as to supply direct current power, the battery management system is activated by supply of direct current power from the second power source when the switch is turned on, and the first relay is on-controlled when determined that the first power source can be used.