Patent ID: 7202632

Claim:
A battery management apparatus for grasping a change in impedance of a battery to reflect the battery management, the apparatus comprising: impedance calculating means for calculating the impedance of the battery using a terminal voltage of the battery, an open circuit voltage thereof, and a current thereof as parameters when variations in the current of the battery and a temperature thereof are respectively within predetermined ranges; and impedance correction value calculating means for comparing the impedance obtained by the impedance calculating means with an initial impedance previously obtained from the initial state of the battery to calculate a correction value depending on the degree of deterioration of the battery, and wherein the impedance calculating means further calculates the impedance at the present moment, and said impedance correction value calculating means calculates a correction value at the present moment by comparing the impedance at the present moment and said initial impedance, and a weighted average is set that is calculated by weighting and averaging the correction value at the present moment and a learned value that is representative of a previous correction value, and wherein the weighted average is set as an updated learned value, and the undated learned value is used as an updated correction value by said battery management apparatus.