Patent ID: 8046181

Claim:
An apparatus for estimating SOH (State Of Health) of a battery based on a battery voltage variation pattern, comprising: a data storing unit for obtaining and storing battery voltage, current and temperature data from a voltage sensing unit, a current sensing unit and a temperature sensing unit, which are coupled to a battery, whenever SOH is estimated; a first SOC (State Of Charge) estimating unit for estimating a first SOC by an Ampere counting manner using the stored battery current data; a second SOC estimating unit for estimating an open-circuit voltage from a battery voltage behavior defined by variation patterns of battery voltages measured and stored at the present and in the past, and calculating and storing a second SOC corresponding to the estimated open-circuit voltage and the battery temperature using predetermined correlations allowing calculation of SOC from the open-circuit voltage and the battery temperature; a weighted mean convergence calculating unit for calculating and storing a convergence value for a weighted mean value of a ratio (or, a SOC variation ratio) of a variation of the second SOC to a variation of the first SOC; and a SOH estimating unit for estimating a battery capacity corresponding to the stored weighted mean convergence value by using a predetermined correlation allowing calculation of the battery capacity from the weighted mean convergence value, estimating a relative ratio of the estimated battery capacity to an initial battery capacity, and storing the relative ratio as SOH.