A battery management system, comprising: an energy storage battery, a power conversion system, PCS, a central monitoring unit, and a direct current converter, wherein the battery management system further comprises a monitoring module and a sampling module, an input terminal of the direct current converter is connected to the PCS, an output terminal of the direct current converter is connected to the energy storage battery, and the direct current converter, the sampling module, and the monitoring module are integrated on a same printed circuit board, PCB; the sampling module is configured to: perform sampling on an operating parameter of the direct current converter to obtain target sampling information, and send the target sampling information to the monitoring module; and the monitoring module is configured to: receive the target sampling information sent by the sampling module, and send the target sampling information to the central monitoring unit, so that the central monitoring unit determines, based on the target sampling information, target charge power for charging the energy storage battery by the PCS; and receive a first control instruction sent by the central monitoring unit, and control, according to the first control instruction, the direct current converter to adjust charge power for charging the energy storage battery by the PCS to the target charge power; characterized in that the battery management system further comprises a power obtaining module, wherein the power obtaining module is configured to: generate an induced current based on an actual current in the direct current converter, generate a power supply current by using the induced current, and supply power to the monitoring module; wherein the power obtaining module comprises a power obtaining transformer, configured to generate an induced current based on an actual current on the direct current converter. the sampling module is configured to: perform sampling on an operating parameter of the direct current converter to obtain target sampling information, and send the target sampling information to the monitoring module; and the monitoring module is configured to: receive the target sampling information sent by the sampling module, and send the target sampling information to the central monitoring unit, so that the central monitoring unit determines, based on the target sampling information, target charge power for charging the energy storage battery by the PCS; and receive a first control instruction sent by the central monitoring unit, and control, according to the first control instruction, the direct current converter to adjust charge power for charging the energy storage battery by the PCS to the target charge power; characterized in that the battery management system further comprises a power obtaining module, wherein the power obtaining module is configured to: generate an induced current based on an actual current in the direct current converter, generate a power supply current by using the induced current, and supply power to the monitoring module; wherein the power obtaining module comprises a power obtaining transformer, configured to generate an induced current based on an actual current on the direct current converter.