STATE ESTIMATION METHOD OF CHARGEABLE BATTERY AND DEVICE THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a state estimation method of a chargeable battery for accurately estimating a charging state.SOLUTION: A state estimation method of a chargeable battery determines, from current of the battery, that the battery is in a charging and discharging stop state from a charging and discharging state; measures secular change of voltage reduction at the time t from the charging and discharging stop state; expresses alleviation behavior of the measured voltage as an approximate curve with an alleviation function Fv(t); and estimates the charging state amount of the battery from the alleviation function Fv(t). The alleviation function Fv(t) is expressed by the sum of exponential functions having a plurality of different time constants related to different events respectively generated in the battery.