Storage amount estimation device, energy storage module, storage amount estimation method, and computer program

A storage amount estimation method for estimating a storage amount of an energy storage device containing an active material in a positive electrode and/or a negative electrode, the active material generating a plurality of electrochemical reactions according to transition of charge-discharge, the active material exhibiting hysteresis between a first characteristic that is a storage amount-voltage charge characteristic and a second characteristic that is a storage amount-voltage discharge characteristic, the storage amount estimation method comprising:

• storing the first characteristic, the second characteristic, and voltage history of the charge-discharge in a storage unit;
• acquiring voltage at the energy storage device and setting voltage acquired after the acquired voltage is greater than a first threshold to a reference voltage;
• acquiring a third characteristic that is a storage amount-voltage charge characteristic and/or a fourth characteristic that is a storage amount-voltage discharge characteristic for reference, the third characteristic and the fourth characteristic being for reference in estimating the storage amount from the acquired voltage, at least one of the third characteristic or the fourth characteristics is acquired based on the reference voltage;
• and
• estimating the storage amount based on the voltage history of the charge-discharge, the third characteristic and/or the fourth characteristic, and the acquired voltage.

A non-transitory computer-readable medium storing a computer program causing a computer that estimates a storage amount of an energy storage device containing an active material in a positive electrode and/or a negative electrode to perform pieces of processing, the active material generating a plurality of electrochemical reactions according to transition of charge-discharge, the active material exhibiting hysteresis between a first characteristic that is a storage amount-voltage charge characteristic and a second characteristic that is a storage amount-voltage discharge characteristic, the pieces of processing comprising:

• acquiring voltage at the energy storage device and setting voltage acquired after the acquired voltage is greater than a first threshold to a reference voltage;
• acquiring a third characteristic that is a storage amount-voltage charge characteristic and/or a fourth characteristic that is a storage amount-voltage discharge characteristic for reference by referring to the first characteristic, the second characteristic, and voltage history of the charge-discharge, the third characteristic and the fourth characteristic being for references in estimating the storage amount from the acquired voltage, at least one of the third characteristic or the fourth characteristics is acquired based on the reference voltage;
• estimating the storage amount based on the voltage history of the charge-discharge, the third characteristic and/or the fourth characteristic, and the acquired voltage.