The invention relates to a method for identifying abnormal battery cells in a
battery pack. The method comprises the following steps: step S1, acquiring accumulated
equalization time of each single
battery cell in the
battery pack in a preset time window; s2, for each single
cell, calculating a relative self-
discharge rate based on the accumulative
equalization time; s3, for each single
cell, judging whether the relative self-
discharge rate exceeds a preset threshold value or not; and S4, under the condition that the relative self-
discharge rate exceeds the preset threshold value, determining that the corresponding single
battery cell is an abnormal
battery cell. According to some embodiments of the invention, an
algorithm for online calculation of the relative self-
discharge rate of a single
cell based on the accumulative
equalization time is provided, so that a suspicious cell can be recognized online in real time, whether the suspicious cell is abnormal can be judged, early warning can be performed in combination with means such as
remote diagnosis, and the accuracy and the reliability of the
system are improved. Therefore, the abnormal condition of the battery cell is effectively prevented.