Abstract: The car power source apparatus is provided with a car driving battery, a heater which heats the driving battery, a control circuit which controls power to the heater, and a temperature sensor to detect battery temperature and issue a detected temperature signal to the control circuit. The control circuit is provided with a timer which stores a warming-time to maintain the driving battery in a warmed-up condition via the heater after the car ignition switch has been turned off. During the warming-time, which is until the timer times-out with the ignition switch turned to the off state, the control circuit controls power to the heater to maintain the driving battery in a warmed-up condition.

Abstract: The car power source apparatus is provided with a car driving battery, a heater which heats the driving battery, a control circuit which controls power to the heater, and a temperature sensor to detect battery temperature and issue a detected temperature signal to the control circuit. The control circuit is provided with a timer which stores a warming-time to maintain the driving battery in a warmed-up condition via the heater after the car ignition switch has been turned off. During the warming-time, which is until the timer times-out with the ignition switch turned to the off state, the control circuit controls power to the heater to maintain the driving battery in a warmed-up condition.

Abstract: An erasable programmable ROM has a storage area which is divided into blocks having a predetermined block length, each assigned a block address and provided with information. With reference to block addresses and information, the CPU specifies the blocks to be used for storing and writes a file to the ROM in block units. The CPU writes the file first to a blank block having a writing start mark written the blank block when the blank block is present or to an optional blank block if otherwise and then successively to other blank blocks. On completion of writing, the CPU searches for a blank block downstream from the last block used for writing and writes a writing start mark to the blank block found.