Patent ID: 7413827

Claim:
A car power source apparatus comprising: a driving battery which powers an electric motor to drive a car; a plurality of heaters for heating the driving battery until a set temperature is reached; a control circuit for controlling power to the heaters; a temperature sensor for detecting battery temperature and issuing a detected temperature signal to the control circuit; a surrounding temperature sensor for detecting temperature surrounding the driving battery and issuing a detected temperature signal to the control circuit, a switching circuit for switching a power supply to the heaters from the driving battery and from a commercial power source; and a warming timer for maintaining the driving battery in a warmed-up condition by operation of the heaters when an ignition switch of the car is turned off; wherein the control circuit changes the set temperature corresponding to the surrounding temperature detected by the surrounding temperature sensor when the car is not being driven and the driving battery is heated via the heaters powered by the driving battery, wherein, when the heaters are powered by the driving battery, the control circuit controls power to the heaters until the warming timer times-out, and wherein, when an input of commercial power is detected and the heaters are powered by commercial power, the control circuit controls power to the heaters until the car is started.