BATTERY DIAGNOSIS DEVICE, BATTERY DIAGNOSIS METHOD, BATTERY PACK AND ELECTRIC VEHICLE

A battery diagnosis apparatus according to the present disclosure includes a voltage sensor to generate a voltage signal indicating a battery voltage of a battery; a current sensor to generate a current signal indicating a battery current of the battery; and a control circuit. The control circuit determines a capacity curve indicating a relationship between the battery voltage and a charge capacity in a set voltage range based on the voltage signal and the current signal collected at each unit time for a constant current charging period. The control circuit determines a differential curve indicating a relationship between the battery voltage and a differential capacity in the set voltage range based on the capacity curve. The control circuit determines an approximate straight line of the differential curve using a linear approximation algorithm, and determines whether lithium deposition is present in the battery based on the approximate straight line.