Monitor for battery pack

摘要

For measuring a temperature with a thermistor, an electrical circuit including the thermistor and resistors for voltage division has to be maintained in the normally energized state and a variation in the voltage caused by resistance variation is detected. This requires a considerable amount of power consumption. On the other hand, thermal reed switches SW1 to SWn are mounted on the surfaces of the unit cells 1-1 to 1-n included in the battery pack 10. Each of the thermal reed switches is connected at one end to a common power source VDD and at the other end to a corresponding input terminal of a selector switch 20. The selector switch 20 is responsive to a switch signal from a determining unit 30a for passing selectively and periodically input signals of the input terminals to the determining unit 30a which in turn detects the temperature of a corresponding unit cell on the basis of the input signal selected by the switch signal.