Abstract: A state estimator estimates, based on at least one of a voltage, a current, and a temperature of a secondary battery, a state of the secondary battery including a state of charge (SOC) of the secondary battery. A discharge controller discharges, when a state of non-use of the secondary battery lasts for a predetermined period of time, the secondary battery such that an indicator indicating easiness of storage deterioration of the secondary battery to progress decreases in stages. The indicator includes a parameter that depends on an SOC of the secondary battery. A value of the indicator and a duration of stay in each stage are set such that a predetermined relationship holds between products in a plurality of stages, each of the products being derived from multiplying the value of the indicator and the duration of stay in each stage.

Abstract: According to the present invention, a state management unit measures or estimates the AC resistance value of a secondary cell at a plurality of time points, estimates a predicted transition of the AC resistance value of the secondary cell on the basis of the AC resistance value at the plurality of time points, and estimates a remaining use period until the AC resistance value of the secondary cell reaches a resistance threshold value corresponding to a time point at which usage of the secondary cell ends. When the remaining use period of the secondary cell becomes shorter than a prescribed period, an operation management unit changes the usage manner of the secondary cell method to a usage manner that has a smaller load on the secondary cell, or stops the usage of the secondary cell.

Abstract: A deterioration diagnosis unit 21a of an arithmetic unit 20 constituting a remaining performance evaluation system 3 diagnoses the deterioration degree of a secondary battery 5 that has already been used for primary use based on an actual measurement value. The deterioration speed update unit 21b updates the deterioration speed of the secondary battery 5 based on the diagnosis result of the secondary battery 5. The remaining performance estimation unit 21c estimates the remaining performance of the secondary battery 5 after the start of secondary use based on the updated deterioration speed and a usage method at the time of the secondary use of the secondary battery 5.

Abstract: According to the present invention, a state management unit measures or estimates the AC resistance value of a secondary cell at a plurality of time points, estimates a predicted transition of the AC resistance value of the secondary cell on the basis of the AC resistance value at the plurality of time points, and estimates a remaining use period until the AC resistance value of the secondary cell reaches a resistance threshold value corresponding to a time point at which usage of the secondary cell ends. When the remaining use period of the secondary cell becomes shorter than a prescribed period, an operation management unit changes the usage manner of the secondary cell method to a usage manner that has a smaller load on the secondary cell, or stops the usage of the secondary cell.

Abstract: A state estimator 141 estimates, based on at least one of a voltage, a current, and a temperature of a secondary battery 20, a state of the secondary battery 20 including a state of charge (SOC) of the secondary battery 20. A discharge controller 142 discharges, when a state of non-use of the secondary battery 20 lasts for a predetermined period of time, the secondary battery 20 such that an indicator indicating easiness of storage deterioration of the secondary battery 20 to progress decreases in stages. The indicator includes a parameter that depends on an SOC of the secondary battery 20. A value of the indicator and a duration of stay in each stage are set such that a predetermined relationship holds between products in a plurality of stages, each of the products being derived from multiplying the value of the indicator and the duration of stay in each stage.