Patent ID: 6445162
Filing Date: 2002-09-03
Classification: G01R,H01M,H02J,Y02E

Abstract:
A battery circuit capable of supplying an electric current to an external load outside the battery circuit and detecting a battery remaining capacity, comprisinga secondary battery, a storage capacitor, at least two switches, the first switch connecting the secondary battery to the storage capacitor and the second switch, and the second switch connecting the storage capacitor to the external load, and a storage capacity voltage monitor circuit coupled to terminals of the storage capacitor, wherein a remaining capacity of the secondary battery is measured by measuring a terminal voltage of the storage capacitor with the storage capacity voltage monitor circuit before the first switch is turned ON and a charge from the secondary battery flows to the storage capacitor, and measuring the terminal voltage of the storage capacitor with the storage capacity voltage monitor circuit after the first switch element is turned ON and then OFF.