Battery pack and signal transmission system

Abstract

A battery pack BP having terminals T1, T2, and T3, a detecting circuit, a signal generating circuit, a temperature, voltage, and current detecting circuit, a switching circuit, and a secondary battery connected to the switching circuit. A first external signal generating unit may be connected to terminals T1 and T2 and a second external signal generating unit may be connected to terminals T2 and T3. The detecting circuit detects whether the first or second external signal generating units has been connected. In so doing, the detecting circuit may detect an impedance of the first external signal generating unit and may detect a terminal voltage of the second external signal generating unit. The on/off operations of the switching circuit SW may be controlled in accordance with the detection result.

Dependencies are inferred from the claim text.