STATE SENSING DEVICE AND STATE DETECTION METHOD OF SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To detect a state of a secondary battery carried in a vehicle by estimating the degree of polarization correctly. SOLUTION: The monitoring method of a battery comprises steps of: detecting battery voltage V and current I (S102); computing the polarization index indicating the degree of the polarization based on the activation polarization and the concentration polarization of the secondary battery (S104); computing SOC corresponding to the battery voltage V (S200) when all the voltage V, the current I, and the polarization index satisfy data measurement conditions (in the case of YES at S110); computing capacity variationΔQ based on the integrated time of the charging and discharge currents I of a battery (S300); computing a estimated full charging capacity Q for judging whether the battery is carrying out cycle degradation (S500) when capacity estimation conditions are satisfied (in the case of YES at S400); and (S700) which turns on LED of the battery life alarm display arranged in a meter panel or the like when the estimated full charging capacity Q is smaller than a predetermined threshold in advance (in the case of YES at S600). COPYRIGHT: (C)2005,JPO&NCIPI