A battery management system for multiple battery cells (CELL1,..., CELL40) of a vehicle, the system comprising: a sensing unit for sequentially detecting a voltage of each battery cell (CELL1,..., CELL40) according to an adjustable sampling rate; characterized in that there is a main control unit coupled to the sensing unit, the main control unit determining an operation state of the vehicle, the main control unit generating one of at least two sampling signals depending on the operation state of the vehicle, the main control unit transmitting the one of at least two sampling signals to the sensing unit, wherein the sampling signals include a first sampling signal and a second sampling signal, wherein a sampling time period of the first sampling signal is shorter than a sampling time period of the second sampling signal, wherein the first and second sampling signals comprise a first control signal, a second control signal, and a third control signal and wherein the main control unit generates the first sampling signal whenever the vehicle is in a running state, and generates the second sampling signal whenever the vehicle is in an idle state, and the sensing unit further comprises: multiple cell relays (111_1,..., 111_40) adapted to be coupled to the battery cells (CELL1,..., CELL40), the cell relays (111_1,..., 111_40) receiving the first control signal (S1_1,..., S1_40) from the main control unit; a first relay coupled to each of the cell relays (111_1,..., 1111_40), the first relay receiving the second control signal from the main control unit; a capacitor coupled to the first relay; a second relay coupled to the capacitor, the second relay receiving the third control signal from the main control unit; and a differential amplification terminal coupled to the second relay, the differential amplification terminal detecting the voltage of each battery cell (CELL1,..., CELL40) and amplifying the voltage of each battery cell (CELL1,..., CELL40). a sensing unit for sequentially detecting a voltage of each battery cell (CELL1,..., CELL40) according to an adjustable sampling rate; characterized in that there is a main control unit coupled to the sensing unit, the main control unit determining an operation state of the vehicle, the main control unit generating one of at least two sampling signals depending on the operation state of the vehicle, the main control unit transmitting the one of at least two sampling signals to the sensing unit, wherein the sampling signals include a first sampling signal and a second sampling signal, wherein a sampling time period of the first sampling signal is shorter than a sampling time period of the second sampling signal, wherein the first and second sampling signals comprise a first control signal, a second control signal, and a third control signal and multiple cell relays (111_1,..., 111_40) adapted to be coupled to the battery cells (CELL1,..., CELL40), the cell relays (111_1,..., 111_40) receiving the first control signal (S1_1,..., S1_40) from the main control unit; a first relay coupled to each of the cell relays (111_1,..., 1111_40), the first relay receiving the second control signal from the main control unit; a capacitor coupled to the first relay; a second relay coupled to the capacitor, the second relay receiving the third control signal from the main control unit; and a differential amplification terminal coupled to the second relay, the differential amplification terminal detecting the voltage of each battery cell (CELL1,..., CELL40) and amplifying the voltage of each battery cell (CELL1,..., CELL40).