Patent attributes
A battery temperature raising device is provided which raises, in a vehicle having an internal combustion engine and a motor using a chargeable battery as a power source, the temperature of the battery during charging in a state that the internal combustion engine is stopped. The battery temperature raising device includes a main circuit where cooling water circulates through the internal combustion engine; a first battery circuit connected in parallel to the main circuit; and a second flow rate control valve arranged in the first battery circuit. A first temperature raising control for raising the temperature of the battery is executed, when a battery temperature is equal to or below a predetermined temperature and an engine water temperature is higher than the battery temperature during charging the battery, by opening the second flow rate control valve and introducing the cooling water inside the main circuit into the first battery circuit.