Disclosed is a battery management apparatus, which includes: a pre-charging unit having a plurality of switches and connected to the first main relay in parallel, the pre-charging unit being connected between the second main relay and the second charging/discharging terminal; a control unit configured to control the plurality of switches so that an output voltage of the battery module is reduced to a reduced voltage and output between the first charging/discharging terminal and the second charging/discharging terminal; and a diagnosing unit configured to diagnose a connection state in the load based on a load current value of the current flowing in the load to which the reduced voltage is applied.