US Patent 7619386 Battery pack, charging control method, and application device

A battery pack having a secondary battery and a circuit that controls charging and discharging of the secondary battery is provided. The battery pack has a computer and a charging control section. The computer communicates with another computer disposed in a charging device and authenticates the charging device. The charging control section, controlled by the computer, supplies a charging current to the secondary battery when the charging device has been successfully authenticated and shuts off the charging current when the charging device has not been successfully authenticated.