BATTERY STATE DETERMINATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a battery state determination device capable of accurately estimating the deterioration state of a storage battery which has two different deterioration modes.SOLUTION: The battery state determination device includes: a voltage measurement section that measures open voltage of a storage battery; a residual capacity estimation section that estimates residual capacity of the storage battery based on the measured open voltage; an internal resistance measurement section that measures internal resistance of the storage battery; a calculation section that calculates deterioration rate of the internal resistance based on the measured internal resistance; an estimation section that makes a first estimation on the deterioration state of the storage battery based on the estimated residual capacity and the calculated deterioration rate of the internal resistance.