BATTERY CAPACITY CALCULATING METHOD, BATTERY CAPACITY CALCULATING APPARATUS, AND BATTERY CAPACITY CALCULATING PROGRAM

摘要

A battery capacity calculating method that can calculate, with an extremely high degree of precision, the remaining capacity of a secondary battery particularly in an ending stage of discharge independently of environmental conditions, such as temperature, degradation and the like. A battery capacity calculating apparatus (10) includes a voltage measuring circuit (11) for measuring the terminal voltage (Vmea) of a battery (1) during discharging thereof, a current measuring circuit (12) for measuring a current value (I) of the battery (1) during discharging thereof, and a control circuit (13) for calculating the remaining capacity and/or remaining power. A calculating part (15) in the control circuit (13) calculates, based on the terminal voltage (Vmea) and current value (I) measured by the voltage measuring circuit (11) and current measuring circuit (12), a discharge capacity (Qmea) and an apparent discharge capacity (Qocv), and then predicts, during discharge, based on a capacity gap (DeltaQ) that is a difference therebetween, a discharge curve (Cpre) that will appear in the future including an ending stage of discharge, and then calculates, based on the predicted discharge curve (Cpre), the remaining capacity and/or remaining power of the battery (1).