PROTECTION CIRCUIT-EQUIPPED SECONDARY BATTERY

A heater 13 and a thermistor 14 are connected in parallel, and a main fuse 11 is connected in series with thus formed parallel circuit to form a protective circuit 6. In a secondary battery 5 of the present invention, a charging/discharging current passes through the protective circuit 6, so that current is limited by the operation of the thermistor 14 when the voltage applied during abnormal conditions is relatively low while the main fuse 11 blows when the voltage during abnormal conditions is high.