A battery management apparatus connectable to a power conversion system through a first terminal (P+) and a second terminal (P-) of the power conversion system, the battery management apparatus comprising: a first battery pack; a second battery pack; a first switch connected in series to the first battery pack between the first terminal and the second terminal; a second switch connected in series to the second battery pack between the first terminal and the second terminal; and a control unit operably coupled to the first switch and the second switch and comprising a first slave controller and a second slave controller, wherein the first slave controller is configured to measure a pack current of the first battery pack and the second slave controller is configured to measure a pack current of the second battery pack, characterised in that the control unit is configured to: stop, in response to a first notification signal received from the power conversion system, balancing steps for parallel connection between the first battery pack and the second battery pack, the first notification signal indicating that power supply from an electrical grid electrically connected to the power conversion system is interrupted, execute a shutdown preparation mode at a time point at which a preset preparation period has passed from a time point at which the first notification signal was received, the shutdown preparation mode is a mode in which the control unit measures the pack current of the first battery pack and the pack current of the second battery pack through the first and second slave controllers, respectively, and determines whether the measured pack current of the first battery pack and the measured pack current of the second battery pack are within a preset current range, and turn off the first switch and the second switch when the pack current of the first battery pack and the pack current of the second battery pack are determined to be within the preset current range indicating a state in which the first switch and the second switch are not damaged even though the first switch and the second switch are turned off. a first battery pack; a second battery pack; a first switch connected in series to the first battery pack between the first terminal and the second terminal; a second switch connected in series to the second battery pack between the first terminal and the second terminal; and a control unit operably coupled to the first switch and the second switch and comprising a first slave controller and a second slave controller, wherein the first slave controller is configured to measure a pack current of the first battery pack and the second slave controller is configured to measure a pack current of the second battery pack, characterised in that the control unit is configured to: stop, in response to a first notification signal received from the power conversion system, balancing steps for parallel connection between the first battery pack and the second battery pack, the first notification signal indicating that power supply from an electrical grid electrically connected to the power conversion system is interrupted, execute a shutdown preparation mode at a time point at which a preset preparation period has passed from a time point at which the first notification signal was received, the shutdown preparation mode is a mode in which the control unit measures the pack current of the first battery pack and the pack current of the second battery pack through the first and second slave controllers, respectively, and determines whether the measured pack current of the first battery pack and the measured pack current of the second battery pack are within a preset current range, and turn off the first switch and the second switch when the pack current of the first battery pack and the pack current of the second battery pack are determined to be within the preset current range indicating a state in which the first switch and the second switch are not damaged even though the first switch and the second switch are turned off. stop, in response to a first notification signal received from the power conversion system, balancing steps for parallel connection between the first battery pack and the second battery pack, the first notification signal indicating that power supply from an electrical grid electrically connected to the power conversion system is interrupted, execute a shutdown preparation mode at a time point at which a preset preparation period has passed from a time point at which the first notification signal was received, the shutdown preparation mode is a mode in which the control unit measures the pack current of the first battery pack and the pack current of the second battery pack through the first and second slave controllers, respectively, and determines whether the measured pack current of the first battery pack and the measured pack current of the second battery pack are within a preset current range, and turn off the first switch and the second switch when the pack current of the first battery pack and the pack current of the second battery pack are determined to be within the preset current range indicating a state in which the first switch and the second switch are not damaged even though the first switch and the second switch are turned off.