METHOD FOR ESTIMATING CHARGING RATE, DEVICE FOR ESTIMATING CHARGING RATE, BATTERY SYSTEM AND BATTERY SYSTEM FOR VEHICLE

摘要

PROBLEM TO BE SOLVED: To provide a method for estimating a charging rate or the like capable of correctly estimating the charging rate by precisely approximating an open circuit voltage of a secondary battery. SOLUTION: In the method for estimating the charging rate of the present invention, the initial setting of a parameter required for processing is performed so as to estimate the charging rate of the secondary battery for supplying power to a load (Step S11). The voltage of the secondary battery is then measured within a specified period of time after the completion of an electric charge and discharge, and a plurality of voltage measurement values are acquired on a time axis (Step S12). A successive calculation is performed by using the values (Steps S14 to S21). A coefficient of index attenuation function of quaternary or more approximating the time characteristic of the open circuit voltage of the secondary battery is determined. At least the convergence value of the open circuit voltage of the secondary battery is calculated based on the determined coefficient (Step S22). The charging rate is estimated based on the convergence value of the open circuit voltage (Step S24). COPYRIGHT: (C)2005,JPO&NCIPI