METHOD OF DETECTING DETERIORATION OF SECONDARY BATTERY AND BATTERY CHARGER PROVIDED WITH FUNCTION OF DETECTING DETERIORATION

摘要

PROBLEM TO BE SOLVED: To realize a method which has not been realized conventionally for accurately detecting a degree of deterioration of a secondary battery. SOLUTION: In a secondary battery charged by constant current/voltage charging, a charging capacity at constant current charging is obtained to estimate a degree of deterioration of the secondary battery from correlation between the charging capacity and a battery capacity, a drop amount of a current just after switching to the constant voltage charging after starting the charging is measured to estimate the degree of deterioration of the secondary battery from correlation between the drop amount of the current and the battery capacity, and the degree of deterioration of the secondary battery is estimated from a change rate of a current or a current value after switching to the constant voltage charging from the constant current charging after starting the charging.