A secondary battery has a progressively deteriorating SOC in which battery performance deteriorates when the secondary battery is stored, and is charged and discharged by a control device. An information processing device stores a preset first threshold smaller than the progressively deteriorating SOC of the secondary battery and a preset second threshold greater than the progressively deteriorating SOC, and separates the range from the minimum SOC to the maximum SOC of the secondary battery into, at least, two regions by setting the section from the first threshold to the second threshold as a boundary to thereby cause the control device to charge or discharge the secondary battery within any of the above regions.