| 摘要 |
PROBLEM TO BE SOLVED: To provide a battery protective circuit having high reliability and a double constitution of overcharge prevention for preventing a battery breakage due to continuation of overcharging state. SOLUTION: This battery protective circuit doublly protects a secondary cell 3 against overcharging by an overcharging preventing function circuit A, having a main control means 1 for detecting overcharging, overdischarging or overdischarging current of the cell 3 to control a first FET 11 or a second FET 12 to a shut-off state, and a sub-protective circuit B having a sub-control means 2 for controlling a third FET 13 to a shut-off state, when an overcharge preventing function is not normally operated by the means 1. |
