A regulating device for balancing battery sets, comprising: a common mode choke, comprising an input side and an output side, wherein the input side is configured to be coupled to a power-supply device, and the output side comprises a first terminal and a second terminal, a switching device, comprising a first input node, a second input node, a first output node, a second output node and a third output node; wherein the first input node is coupled to the first terminal of the common mode choke, and the second input node is coupled to the second terminal of the common mode choke; wherein the first output node is coupled to a first battery set, and the second output node is coupled to a second battery set, and the third output node is floated; and a first control unit, configured to compare a first terminal voltage of the first output node to a second terminal voltage of the second output node for controlling the first input node to be selectively connected to the first output node or the second output node and controlling the second input node to be selectively connected to the second output node or the third output node; wherein the first control unit is configured to control the first input node to connect to the second output node, when the first control unit determines that the first terminal voltage is higher than the second terminal voltage by an amount that is outside an error range, and the first control unit is configured to control the second input node to connect to the third output node, when the first control unit identifies that the second terminal voltage is higher than the first terminal voltage by an amount that is outside the error range. a common mode choke, comprising an input side and an output side, wherein the input side is configured to be coupled to a power-supply device, and the output side comprises a first terminal and a second terminal, a switching device, comprising a first input node, a second input node, a first output node, a second output node and a third output node; wherein the first input node is coupled to the first terminal of the common mode choke, and the second input node is coupled to the second terminal of the common mode choke; wherein the first output node is coupled to a first battery set, and the second output node is coupled to a second battery set, and the third output node is floated; and a first control unit, configured to compare a first terminal voltage of the first output node to a second terminal voltage of the second output node for controlling the first input node to be selectively connected to the first output node or the second output node and controlling the second input node to be selectively connected to the second output node or the third output node; wherein the first control unit is configured to control the first input node to connect to the second output node, when the first control unit determines that the first terminal voltage is higher than the second terminal voltage by an amount that is outside an error range, and the first control unit is configured to control the second input node to connect to the third output node, when the first control unit identifies that the second terminal voltage is higher than the first terminal voltage by an amount that is outside the error range.