BATTERY DIAGNOSIS DEVICE AND OPERATION METHOD THEREOF

A battery diagnostic device according to an embodiment disclosed herein may include an interface configured to acquire a voltage value of one or more battery cells measured during a designated time interval and acquire an external temperature of the battery cells, and a controller configured to calculate a difference between voltage values at two points in time included in the designated time interval, select a discharge threshold corresponding to the external temperature and a target point in time of the two points in time, and diagnose a state of the battery cells by comparing the discharge threshold with the difference.