Battery control device, charge and discharge system, parking lot system, secondary battery reuse system, battery control method, and non-transitory strage medium

A battery control method comprising:

• acquiring information relating to a first secondary battery electrically connected to a charge and discharge circuit capable of charging and discharging an electrically connected secondary battery;
• determining whether or not a diagnosis implementation condition regarding the first secondary battery is satisfied based on the information regarding the first secondary battery;
• controlling the charge and discharge circuit to charge the first secondary battery only after discharging or charging the first secondary battery up to a charging start SOC if it is determined that the diagnosis implementation condition is satisfied;
• acquiring measurement data of a voltage and a current of the first secondary battery while the first secondary battery is charged from the charging-start SOC;
• estimating an internal state parameter of the first secondary battery based on the measurement data;
• and
• diagnosing a deterioration state of the first secondary battery based on an estimated value of the internal state parameter of the first secondary battery.

A non-transitory storage medium storing a battery control program causing a computer to:

• acquire information relating to a first secondary battery electrically connected to a charge and discharge circuit capable of charging and discharging an electrically connected secondary battery;
• determine whether or not a diagnosis implementation condition regarding the first secondary battery is satisfied based on the information regarding the first secondary battery;
• control the charge and discharge circuit to charge the first secondary battery only after discharging or charging the first secondary battery up to a charging-start SOC if it is determined that the diagnosis implementation condition is satisfied;
• acquire measurement data of a voltage and a current of the first secondary battery while the first secondary battery is being charged from the charging-start SOC;
• estimate an internal state parameter of the first secondary battery based on the measurement data;
• and
• diagnose a deterioration state of the first secondary battery based on an estimated value of the internal state parameter of the first secondary battery.