Patent ID: 6700383
Filing Date: 2004-03-02
Classification: B60L,G01R,Y02T

Abstract:
A method for detecting a memory effect comprising the steps of:detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery; performing an operation on a variation in a residual battery capacity for a predetermined time period according to at least current integration by multiplying the detected current by a predetermined charge efficiency; detecting a temperature of the secondary battery; calculating a variation in a no-load voltage for the predetermined time period, based on the detected current and an internal resistance corresponding to the detected temperature and the residual battery capacity obtained by the operation; calculating a ratio of the variation in the no-load voltage to the variation in the residual battery capacity; and if the ratio of the variation in the no-load voltage to the variation in the residual battery capacity is not less than a predetermined threshold value, judging as a memory effect occurring in the secondary battery.