| 摘要 |
<p>PROBLEM TO BE SOLVED: To correctly detect the residual capacity of a battery of a lithium ion secondary cell by estimating the irreversible deterioration amount of the battery when left at a high potential. SOLUTION: When the detected voltage of a battery is left at a value exceeding a higher predetermined voltage (e.g. 3.9V when converted into a voltage of a lithium ion secondary cell) than a rated voltage of the battery (e.g. 3.6V of the same converted value), specifically when the battery is left after fully charged, a time at a high voltage state is counted, based on which a capacity deterioration amount Cd of the battery is calculated. A value obtained by subtracting the calculated capacity deterioration amount Cd from a reference capacity (capacity when the battery is fresh) Cr is set as a full charge capacity Cf afterwards. A value obtained by subtracting a discharge amount Cd is from the full charge capacity Cf is a residual capacity Cc. These values are displayed by bar graphs 61, 62, 63.</p> |
