Battery Diagnosing Apparatus and Method

A battery diagnosing apparatus according to an embodiment includes a measuring unit configured to measure an open circuit voltage (OCV) of a battery after charging of the battery is finished and measure a resistance of the battery while the battery is discharged for a predetermined time after the charging of the battery is finished; and a control unit configured to receive voltage information for the OCV and resistance information for the resistance from the measuring unit, calculate a voltage deviation between the OCV and a criterion voltage preset for the battery, calculate a resistance deviation between the resistance and a criterion resistance preset for the battery, and diagnose whether degradation of the battery is accelerated based on the voltage deviation and the resistance deviation.