BATTERY STATE ESTIMATING METHOD AND BATTERY MANAGEMENT SYSTEM

A battery states estimation method comprises the steps of: measuring an electric current value of a battery B at the electric current value detection section 10 and a terminal voltage value of the battery B at the voltage detection section 12 at a time of charge/discharge of the battery; and calculating at least one of such states of the battery as a state of charge (SOC), a state of health (SOH) and a full charge capacity based on the electric current value and the terminal voltage value as measured, wherein when a change in the measured electric current value per second is at a predetermined value or higher, at least one of the SOC, the SOH and the full charge capacity of the battery is calculated not based on the electric current values and the terminal voltage values measured during a period from an occurrence of the change in the electric current value up to a lapse of a predetermined time, but based on the electric current values and the terminal voltage values measured during a battery charge/discharge period other than the lapsed period.