Abnormal cell detection method, abnormal cell detection device, and battery pack

An abnormal cell detection device, comprising:

• a detection device configured to detect a voltage of each of a plurality of cells included in a battery module;
• and
• a battery management system configured to:
• obtain a first plurality of discharge rates for each cell during a first rest period in a cell balancing state,
• prohibit a cell balancing of the plurality of cells if a first cell having a first discharge rate greater than or equal to a first threshold value is detected,
• obtain a second discharge rate during a second rest period for each cell of the plurality of cells in a cell balancing prohibition state, and
• detect an abnormal cell having a second discharge rate greater than or equal to a second threshold value.

A battery pack including an abnormal cell detection device, the battery pack comprising:

• a detection device configured to detect a voltage of each of a plurality of cells included in a battery module;
• and
• a battery management system configured to:
• obtain a first plurality of discharge rates for each cell during a first rest period in a cell balancing state,
• prohibit a cell balancing of the plurality of cells if a first cell having a first discharge rate greater than or equal to a first threshold value is detected,
• obtain a second discharge rate during a second rest period for each cell of the plurality of cells in a cell balancing prohibition state, and
• detect an abnormal cell having a second discharge rate greater than or equal to a second threshold value.