Patent ID: 6127805
Filing Date: 2000-10-03
Classification: G01R

Abstract:
A battery charge level detecting device which detects the charge level of a battery having a first range where the charge level of the secondary battery corresponds to a voltage level of the secondary battery and a second range where the charge level does not correspond to the voltage level of the secondary battery, comprising:a charge level estimating means for estimating the charge level of said second range based on the currents of the charge and discharge of the secondary battery;a charge level calculating means for calculating the charge level of said first range based on a terminal voltage level of the secondary battery;a charge level calibrating means for calibrating said estimated charge level by said calculated charge level when the charge level is in said first range;a charge and discharge device which supplies the electric power to the secondary battery or consumes the electric power of the secondary battery; anda charge and discharge control means which judges the need of calibration of the charge level and controls said charge and discharge device so that the charge level of said secondary battery may be in said first range when a need arises.