Battery safety evaluation apparatus, battery control apparatus, battery safety evaluation method, non-transitory computer readable medium, control circuit, and power storage system

A battery safety evaluation method comprising:

• estimating an estimation value of an inner state parameter of a first battery which is a secondary battery to be evaluated on the basis of data of voltage and current of the first battery measured in charging or discharging the first battery;
• calculating a battery swelling index regarding swelling of the first battery on the basis of first reference data which is reference data at least indicating relationship between a positive electrode capacity and a negative electrode capacity of a secondary battery and is set to correspond to the first battery on the basis of the estimation value;
• and
• evaluating, on the basis of the battery swelling index of the first battery, a battery swelling risk of the first battery to evaluate safety of the first battery or an assembled battery including the first battery.

A non-transitory computer readable medium having a program comprising:

• estimating an estimation value of an inner state parameter of a first battery which is a secondary battery to be evaluated on the basis of data of voltage and current of the first battery measured in charging or discharging the first battery;
• and
• calculating a battery swelling index regarding swelling of the first battery on the basis of first reference data which is reference data at least indicating relationship between a positive electrode capacity and a negative electrode capacity of a secondary battery and is set to correspond to the first battery on the basis of the estimation value;
• and
• evaluating, on the basis of the battery swelling index of the first battery, a battery swelling risk of the first battery to evaluate safety of the first battery or an assembled battery including the first battery.

A control circuit comprising:

• a battery characteristic estimator configured to estimate an estimation value of an inner state parameter of a first battery which is a secondary battery to be evaluated on the basis of data of voltage and current of the first battery measured in charging or discharging the first battery;
• a battery swelling index calculator configured to calculate a battery swelling index regarding swelling of the first battery on the basis of first reference data which is reference data at least indicating relationship between a positive electrode capacity and a negative electrode capacity of a secondary battery and is set to correspond to the first battery on the basis of the estimation value;
• and
• a battery safety evaluator configured to evaluate, on the basis of the battery swelling index of the first battery, a battery swelling risk of the first battery to evaluate safety of the first battery or an assembled battery including the first battery.