Patent ID: 8299800

Claim:
A method of diagnosing a malfunction in an abnormal voltage detecting apparatus, which determines whether there is a malfunction in the abnormal voltage detecting apparatus which detects the voltage of a secondary battery and determines that the voltage of the secondary battery is abnormal when the detected voltage value is outside of a normal voltage range, comprising: breaking an electrical connection between the abnormal voltage detecting apparatus and the secondary battery; connecting the abnormal voltage detecting apparatus to a direct current voltage generating portion which is different than the secondary battery and is able to generate direct current voltage that has a predetermined voltage value that is outside of the normal voltage range; applying the direct current voltage that has the predetermined voltage value that is outside of the normal voltage range to the abnormal voltage detecting apparatus using the direct current voltage generating portion; and determining that there is a malfunction in the abnormal voltage detecting apparatus if it is not determined by the abnormal voltage detecting apparatus that the voltage is abnormal, wherein the direct current voltage generating portion is structured to be able to generate direct current voltage that has a constant voltage value that is outside of the normal voltage range, wherein the direct current voltage generating portion includes a converting apparatus capable of converting voltage from an external power supply that is different than the secondary battery into the direct current voltage that has a predetermined voltage value that is outside of the normal voltage range, the method further comprising: electrically connecting the converting apparatus and the abnormal voltage detecting apparatus to the external power supply; converting the voltage from the external power supply into the direct current voltage; and applying the converted direct current voltage to the abnormal voltage detecting apparatus.