Abstract: For charging a storage battery, e.g. a nickel-cadmium cell, recharging is conducted after the battery is forcibly discharged while the charge voltage stays in a specified range after a period of time from the start of the charging action. Accordingly, the generation of memory effect will be avoided. The charging will successfully be carried out without declining the storage capacity of the battery. In both charge and adaptor modes, output voltage and current are examined whether the battery is coupled correctly or not and if not, their delivery is canceled with producing an alarm display. As the result, the charging to the battery and the power supply to an external electric appliance will be implemented without error.