A battery management system, comprising: a current detecting circuit including a shunt resistor configured to be installed on a high current path of a battery pack, and configured to detect a reference current representing a current flowing through the high current path; a bidirectional switch including a charging field effect transistor and a discharging FET connected in series, and configured to be installed on the high current path; and a control unit operably coupled to the current detecting circuit and the bidirectional switch, and configured to detect a first voltage across the charging FET and a second voltage across the discharging FET while a first high level voltage is applied to a gate of the charging FET and a second high level voltage is applied to a gate of the discharging FET, characterized in that the control unit is further configured to: acquire an on-state resistance associated with a drain current corresponding to the reference current as a first reference resistance from a first lookup table associated with the first high level voltage by using the reference current as an index in response to the first high level voltage being equal to the second high level voltage, wherein the first lookup table comprises data indicating a relationship between drain current and on-state resistance of the charging FET and the discharging FET when the first high level voltage is applied as a gate voltage, calculate a first current by dividing the first voltage by the first reference resistance, and determine a failure in the current detecting circuit based on a difference between the reference current and the first current. a current detecting circuit including a shunt resistor configured to be installed on a high current path of a battery pack, and configured to detect a reference current representing a current flowing through the high current path; a bidirectional switch including a charging field effect transistor and a discharging FET connected in series, and configured to be installed on the high current path; and a control unit operably coupled to the current detecting circuit and the bidirectional switch, and configured to detect a first voltage across the charging FET and a second voltage across the discharging FET while a first high level voltage is applied to a gate of the charging FET and a second high level voltage is applied to a gate of the discharging FET, characterized in that the control unit is further configured to: acquire an on-state resistance associated with a drain current corresponding to the reference current as a first reference resistance from a first lookup table associated with the first high level voltage by using the reference current as an index in response to the first high level voltage being equal to the second high level voltage, wherein the first lookup table comprises data indicating a relationship between drain current and on-state resistance of the charging FET and the discharging FET when the first high level voltage is applied as a gate voltage, calculate a first current by dividing the first voltage by the first reference resistance, and determine a failure in the current detecting circuit based on a difference between the reference current and the first current. acquire an on-state resistance associated with a drain current corresponding to the reference current as a first reference resistance from a first lookup table associated with the first high level voltage by using the reference current as an index in response to the first high level voltage being equal to the second high level voltage, wherein the first lookup table comprises data indicating a relationship between drain current and on-state resistance of the charging FET and the discharging FET when the first high level voltage is applied as a gate voltage, calculate a first current by dividing the first voltage by the first reference resistance, and determine a failure in the current detecting circuit based on a difference between the reference current and the first current.