Patent ID: 7557584
Filing Date: 2009-07-07
Classification: G01R

Abstract:
1. A method for estimating a charge/discharge electricity amount of a secondary battery comprising: a step of measuring a pair of data consisting of a current flowing through the secondary battery and a terminal voltage of the secondary battery corresponding to the current, thus obtaining a plurality of pairs of data, a step of, when specific selection conditions are satisfied, the specific selection conditions including (i) the current in charging and discharging the secondary battery is within a first predetermined range, (ii) a number of the plurality of pairs of data is greater than or equal to a predetermined number, and (iii) a charge/discharge electricity amount during collection of the plurality of pairs of data is within a second predetermined range, calculating a no-load voltage as a voltage intercept at a current of zero in a straight-line approximation obtained by statistical processing with respect to the plurality of pairs of data, a step of, when the specific selection conditions are not satisfied and one of specific current conditions and voltage conditions continue to be met for a certain amount of time, calculating an open circuit voltage from the terminal voltage of the secondary battery, the component resistance of the secondary battery and an average current, a step of calculating a change (ΔV a step of calculating an estimated charge/discharge electricity amount (ΔQ