Patent attributes
An equipment and method for charging a secondary battery are provided to quickly and surely charge a secondary battery (secondary batteries) while preventing the secondary battery (batteries) from overcharging or insufficient charging. Special charging voltage Es is applied to a secondary battery for a predetermined time, and then the applied voltage is switched to equilibrium voltage Eeq for establishing equilibrium cell potential of the secondary battery in its fully charged condition, wherein the special charging value Es is larger than the equilibrium value Eeq. Electric current i is detected while application of the equilibrium voltage Eeq. If the detected electric current i is larger than standard electric current J for finishing charging, the above detection and charging are repeated; otherwise, charge of the secondary battery 1 is halted.
