Battery charging/discharging apparatus and battery charging/discharging method

Abstract

When a battery is in standby mode, a microcomputer switches to sleep mode if no charging/discharging current is supplied within a predetermined time, and controls a timer so as to start measuring the standby time of the battery. When a charging/discharging current is supplied, the microcomputer switches to wake-up mode, and controls the timer so as to stop measuring the standby time. Then, the microcomputer reads the measured standby time. Based on the read standby time, the microcomputer calculates the correction value to correct the currently stored remaining battery capacity value.

what is claimed is:  
     
         1 . A battery charging/discharging apparatus for determining the remaining capacity of a battery, comprising: 
 measuring means for measuring a standby time of the battery;    correction value calculating means for calculating a correction value for the remaining capacity of the battery based on the standby time measured by said measuring means; and    correcting means for correcting a current remaining capacity value of the battery based on the correction value calculated by said correction value calculating means.    
     
     
         2 . A battery charging/discharging apparatus according to  claim 1 , further comprising determining means for determining whether or not the standby time has reached a predetermined time, 
 wherein said correction value calculating means calculates the correction value for the remaining capacity of the battery at a predetermined time interval based on the result of said determining means.    
     
     
         3 . A battery charging/discharging method of a battery charging/discharging apparatus for determining the remaining capacity of a battery, said battery charging/discharging method comprising the steps of: 
 measuring a standby time of the battery;    calculating a correction value for the remaining capacity of the battery based on the standby time measured in the measuring step; and    correcting a current remaining capacity value of the battery based on the correction value calculated in the calculating step.    
     
     
         4 . A battery charging/discharging apparatus for determining the remaining capacity of a battery, comprising: 
 detecting means for detecting a cell voltage;    reading means for reading an appropriate remaining capacity value based on the cell voltage detected by said detecting means;    comparing means for comparing the appropriate remaining capacity value read by said reading means with a currently stored remaining capacity value; and    updating means for updating the currently stored remaining capacity value based on the result of said comparing means.    
     
     
         5 . A battery charging/discharging apparatus according to  claim 4 , further comprising setting means for setting the appropriate remaining capacity value that is suitable for the cell voltage.  
     
     
         6 . A battery charging/discharging method of a battery charging/discharging apparatus for determining the remaining capacity of a battery, said battery charging/discharging method comprising the steps of: 
 detecting a cell voltage;    reading an appropriate remaining capacity value based on the cell voltage detected in the detecting step;    comparing the appropriate remaining capacity value read in the reading step with a currently stored remaining capacity value; and    updating the currently stored remaining capacity value based on the result in the comparing step.