Patent ID: 7830122

Claim:
A battery management system coupled to a battery formed with a pack having a plurality of battery cells including first and second battery cells, the battery management system comprising: a control signal generator outputting a first control signal, and second, third, and fourth control signals having a first level at different timing from the first control signal; first and second relays respectively transmitting cell voltages of the first and second battery cells by being turned on in response to the first level of the first and second control signals; a third relay transmitting the cell voltage transmitted through one of the first and second relays in response to the third control signal with the first level; a charging unit storing the cell voltage transmitted from the third relay; a fourth relay transmitting the stored cell voltage of the charging unit in response to the first level of the fourth control signal; and an A/D converter converting the cell voltage transmitted through the fourth relay into digital data, wherein the control signal generator makes the first and second control signals to be a second level excluding the first level when the fourth control signal is the first level and makes the third control signal to be the second level.