METHOD AND APPARATUS OF ESTIMATING STATE OF HEALTH STATE OF BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a low-cost estimation method of estimating a state of health of a battery in which the estimation method is easy.SOLUTION: A method of estimating a state of health of a battery according to the present invention includes the steps of: measuring an internal resistance of the battery; calculating a voltage drop of the battery by the internal resistance by multiplying the measured internal resistance with a preliminarily set lower limit current; acquiring a lower limit open voltage value of a battery capacity on the basis of the calculated voltage drop; preparing a relationship table between an open voltage value and a state of charge of the battery to acquire a lower limit value SOC-1 on the basis of the relationship table between the open voltage value and the state of charge of the battery; and acquiring a state of health of the battery value by a relationship expression SOH=100%-SOC-1 between the state of health of the battery and the lower limit value SOC-1.