BATTERY FULL CHARGE CAPACITY ESTIMATION DEVICE

PROBLEM TO BE SOLVED: To improve an estimation accuracy of a full charge capacity of a battery which increases a polarization and requires a long time in order to dissolve the polarization.SOLUTION: At the estimation starting time of a full charge capacity when a point associated with a charge rate of a battery B and an open-circuit voltage exists on an SOC-OCV curve for electric discharge, the charge rate of the open-circuit voltage of the battery B before charging is defined as the charge rate of the battery B at a charge starting time with reference to the SOC-OCV curve for discharge. When the point associated with the charge rate of the current battery B and the open-circuit voltage exist on the SOC-OCV curve for charging, the charge rate associated with the open circuit voltage of the battery B before charging is defined as the charge rate of the battery B at the charge starting time with reference to the SOC-OCV curve for charging. A current integrated value which is an integrated value of the current flowing in the battery B during charging is divided by a charge rate difference value which is a result of subtracting the charge rate of the battery B at the charge starting time from the charge rate of the battery B at the charge end time.SELECTED DRAWING: Figure 1 【課題】分極が大きく、かつ、分極解消に長時間を要する電池の満充電容量の推定精度を向上させる。【解決手段】満充電容量の推定開始時、現在の電池Ｂの充電率と開回路電圧とが対応する点が放電用ＳＯＣ−ＯＣＶ曲線上に存在していると、放電用ＳＯＣ−ＯＣＶ曲線を参照し、充電前の電池Ｂの開回路電圧に対応する充電率を、充電開始時の電池Ｂの充電率とし、現在の電池Ｂの充電率と開回路電圧とが対応する点が充電用ＳＯＣ−ＯＣＶ曲線上に存在していると、充電用ＳＯＣ−ＯＣＶ曲線を参照し、充電前の電池Ｂの開回路電圧に対応する充電率を、充電開始時の電池Ｂの充電率とし、充電中の電池Ｂに流れる電流の積算値である電流積算値を、充電終了時の電池Ｂの充電率から充電開始時の電池Ｂの充電率を減算した結果である充電率差分値で除算した結果を電池Ｂの満充電容量として推定する。【選択図】図１