To secure electric power for starting an engine by appropriate battery management.
A vehicle state determining part 11 in a main control part 10 determines the state of a vehicle by acquiring information from an ignition sensor 3, an outside air temperature sensor 4, a camera 5, a navigation system 6, and the like. A threshold setting part 12 sets a notice threshold and a charge threshold based on the outside air temperature and the like. A determining part 14 stops the engine after the battery is charged so as to have at least the notice threshold at the stop of the engine, periodically monitors the residual capacity of the battery during the stop of the engine and charges the battery up to the charge threshold if the residual capacity is less than the notice threshold, and positively charges the battery by controlling the generating efficiency of an alternator 23 if the residual capacity of the battery is less than the notice threshold at the start of the engine.
YAMATO TOSHITAKA
TAKEUCHI HIROSHI
MAENO YOSHIHIKO
SAKIYAMA KAZUHIRO
NAKAMURA MOTOHIRO
TOYOTA MOTOR CORP
Next Patent: AUXILIARY INFORMATION PRESENTING DEVICE