| 摘要 |
PROBLEM TO BE SOLVED: To provide a state-of-charge detector and a state-of-charge detection method capable of dealing with a change in charging efficiency over time, and accurately calculating a state of charge of a battery in use even if the battery is used in an incompletely charged state.SOLUTION: A state-of-charge detector comprises: a charging-current integration unit 33 integrating a charging current of an active battery and generating a charging current integrated value; a discharging-current integration unit 32 integrating a discharging current of the battery and generating a discharging current integrated value; and a charging-efficiency computing unit 35 calculating charging efficiency obtained by dividing a magnitude of the discharging current integrated value by a magnitude of the charging current integrated value if at least either a condition (a) or (b) is satisfied, the condition (a) being a condition that an estimated open voltage of the battery changes and then falls within a predetermined range from an open voltage estimated at a time of starting integration, and the condition (b) being a condition that the charging current integrated value and the discharging current integrated value being greater than a predetermined value. |
