FAULT DIAGNOSIS APPARATUS FOR SWITCHING DEVICES BATTERY PACK FAULT DIAGNOSIS PROGRAM FOR SWITCHING DEVICES AND METHOD OF FAULT DIAGNOSIS FOR SWITCHING DEVICES

摘要

An object of the present invention is to diagnose off-impossibility of a switch element while continuing charging or discharging. A battery protecting device (3) of the present invention comprises a charge blocking FET (31) provided in a current path through which a charging current and a discharging current of a secondary battery (2) flow, And an off command signal is given to the charge blocking FET 31 when the secondary battery 2 is judged to be in a discharged state and the detected charge blocking FET 31 ) Or a voltage according to the voltage between the input and output is smaller than the first reference value.