Patent ID: 9714982
Date: 2017-07-25
CPC Classifications: G01R,H01M,H02J,Y02E

Claim:
1. A method for estimating a remaining capacity of a battery, the method comprising: generating a transient characteristic that represents a correlation between a remaining capacity and a closed circuit voltage, the correlation transitioning from one of a charging-side SOC-CCV characteristic and a discharging-side SOC-CCV characteristic to the other when charging and discharging of the battery have been switched, on the basis of map data of a charging-side SOC -CCV characteristic that represents a correlation between a remaining capacity (SOC) of the battery and a Closed Circuit Voltage (CCV) of the battery when charging has only been conducted from a fully-discharged state to a fully-charged state and of a discharging-side SOC-CCV characteristic that represents a correlation between a remaining capacity of the battery and a closed circuit voltage of the battery when discharging has only been conducted from a fully-charged state to a fully-discharged state; and estimating the remaining capacity of the battery from the closed circuit voltage by using the transient characteristic until polarization of the battery enters a saturated state when charging and discharging of the battery have been switched, wherein the generating comprises generating a transient characteristic that contacts, at a third point, which is a point that has moved from a first point of a remaining capacity and a closed circuit voltage immediately before switching on one of the charging-side SOC-CCV characteristic and the discharging-side SOC-CCV characteristic, and passes near a second point, which is a point of the same remaining capacity on the other of the SOC-CCV characteristics, by an amount of change in remaining capacity required for polarization to reverse and enter a saturated state from the second point, the other of the SOC-CCV characteristics, when charging and discharging of the battery have been switched in the generating of the transient characteristic, wherein the transient characteristic is directed, at the third point, in a direction of a vector which is directed from the second point to the third point.