A battery balancing apparatus, comprising: a detection unit configured to output a first voltage signal indicating voltage of each of a plurality of batteries (BA1~BAm) included in a first battery group; a first selection unit configured to selectively electrically connect each of the plurality of batteries included in the first battery group between a first node and a second node; a resistance adjustment unit configured to selectively electrically connect a first resistor, a second resistor, a series circuit of the first resistor and the second resistor or a parallel circuit of the first resistor and the second resistor between the first node and the second node; and a control unit operably coupled to the detection unit, the first selection unit and the resistance adjustment unit, wherein the control unit is configured to determine at least one of the plurality of batteries included in the first battery group as a first balancing target based on the first voltage signal, the first selection unit is configured to electrically connect the first balancing target between the first node and the second node, and the control unit is further configured to control the resistance adjustment unit based on a first voltage difference between a voltage of the first balancing target and a reference voltage; wherein one end of the first resistor is electrically connected to the first node, one end of the second resistor is electricaly connected to the second node, the resistance adjustment unit includes: a first switch connected between the other end of the first resistor and the second node; a second switch connected between the other end of the second resistor and the first node; and a third switch connected between the other end of the first resistor and the the other end of the second resistor. a detection unit configured to output a first voltage signal indicating voltage of each of a plurality of batteries (BA1~BAm) included in a first battery group; a first selection unit configured to selectively electrically connect each of the plurality of batteries included in the first battery group between a first node and a second node; a resistance adjustment unit configured to selectively electrically connect a first resistor, a second resistor, a series circuit of the first resistor and the second resistor or a parallel circuit of the first resistor and the second resistor between the first node and the second node; and a control unit operably coupled to the detection unit, the first selection unit and the resistance adjustment unit, wherein the control unit is configured to determine at least one of the plurality of batteries included in the first battery group as a first balancing target based on the first voltage signal, the first selection unit is configured to electrically connect the first balancing target between the first node and the second node, and the control unit is further configured to control the resistance adjustment unit based on a first voltage difference between a voltage of the first balancing target and a reference voltage; wherein one end of the first resistor is electrically connected to the first node, one end of the second resistor is electricaly connected to the second node, the resistance adjustment unit includes: a first switch connected between the other end of the first resistor and the second node; a second switch connected between the other end of the second resistor and the first node; and a third switch connected between the other end of the first resistor and the the other end of the second resistor. one end of the first resistor is electrically connected to the first node, one end of the second resistor is electricaly connected to the second node, the resistance adjustment unit includes: a first switch connected between the other end of the first resistor and the second node; a second switch connected between the other end of the second resistor and the first node; and a third switch connected between the other end of the first resistor and the the other end of the second resistor. a first switch connected between the other end of the first resistor and the second node; a second switch connected between the other end of the second resistor and the first node; and a third switch connected between the other end of the first resistor and the the other end of the second resistor.