Battery performance evaluation device, and battery performance evaluation method

摘要

A battery performance evaluation device executes an alternating current impedance acquiring process (S1), an OCV acquiring process (S2), and an SOC estimating process (S3). The alternating current impedance acquiring process involves acquiring a measurement result of an alternating current impedance of a target secondary battery, the alternating current impedance measured by applying an application signal to the target secondary battery within a specific frequency range. The OCV acquiring process involves acquiring an OCV of the target secondary battery. The SOC estimating process involves estimating an SOC of the target secondary battery to be 0%, if an imaginary component of the measurement result of the acquired alternating current impedance at a predetermined frequency within the specific frequency range is greater than or equal to a first threshold value and the acquired OCV value is less than or equal to a second threshold value.