Abstract: A protection apparatus for storage battery for storing and feeding power comprises an anomaly detection unit for detecting an anomalous state in at least one of the voltage, a current flow, and the frequency in at least one of an input power and an output power of the storage battery, the temperature and the pressure in the storage battery, and an external force applied to the storage battery, and a short-circuit unit for shorting both electrodes of the storage battery when an anomaly is detected in at least one of the input power, the output power, and the storage battery.

Abstract: During the charging of a secondary battery, the charging current is maintained, but the value of the current is changed for a short time, and the internal resistance of the battery is calculated from the voltage and the current before and after the changing of the charging current. The charging voltage is determined by adding an extra voltage equivalent to the voltage drop caused by the internal resistance to a designated voltage. Thus, it takes only a short time for stabilizing the voltage when the current is changed, because the charging current is not switched off completely. Therefore, the charging time can be shortened.