Battery Diagnosis Apparatus and Operating Method Thereof

A battery diagnosis method comprising:

• obtaining respective first voltage values of a plurality of respective battery units;
• identifying second voltage values in different idle periods from among the first voltage values;
• for each battery unit of the plurality of battery units:
• determining a voltage gradient indicating a change degree of the second voltage values of the battery unit over time;
• determining a Z-score of the voltage gradient for the battery unit based on an average and a standard deviation of the determined plurality of voltage gradients of the plurality of battery units;
• based on the Z-score outside of a first reference range and the voltage gradient outside of a second reference range, diagnosing the battery unit as an abnormal battery unit.

A non-transitory computer-readable storage medium having stored therein instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

• obtaining respective first voltage values of a plurality of respective battery units;
• identifying second voltage values in different idle periods from among the first voltage values;
• for each battery unit of the plurality of battery units:
• determining a voltage gradient indicating a change degree of the second voltage values of the battery unit over time;
• determining a Z-score of the voltage gradient for the battery unit based on an average and a standard deviation of the determined plurality of voltage gradients of the plurality of battery units;
• and
• based on the Z-score outside of a first reference range and the voltage gradient outside of a second reference range, diagnosing the battery unit as an abnormal battery unit.