Battery management system and battery management method

A battery management method to balance cells of a battery that are connected in series, the method comprising:

• sequentially measuring the cell voltages of the cells;
• comparing the measured cell voltages to a reference voltage, to determine if the cells are unbalanced;
• balancing the unbalanced cells,
• wherein the measuring and the balancing are not simultaneously performed on any two of the cells that are directly adjacent to each other.

A battery management system, comprising:

• cells connected in series, which have cell voltages;
• a cell balancing unit that balances the cell voltages;
• a cell selecting unit that selectively establishes an electrical connection to a selected one of the cells, via to power lines that are shared by pairs of the cells;
• a micro-control unit (MCU) that measures the cell voltage of the cells, controls the operations of the cell balancing unit and the cell selecting unit,
• wherein when the cell selecting unit establishes an electrical connection to the selected cell, the MCU measures the voltage of the selected cell and prevents the cell balancing unit from balancing the selected cell and the cells that share the power lines through which the electrical connection is established, while the cell voltage of the selected cell is being measured.