The invention relates to chargers of lithium-ion batteries. The system contains a common control block and control blocks of each of the multitude of battery cells, where each cell of the multitude of cells is controlled by its own control block, which contains a micro-controller that has the capabilities to receive data about the condition of the cell, transfer the received information to the block of common control, and balance voltages of cells by high currents, where the balancing mode efficiently operates in any mode of the battery operation, where the multitude of cells of the accumulator batter are connected in series by direct current, and in parallel by alternating current through the system of DC/AC converter balancing, where the converters are synchronized by the common control signal from the common control block. The invention reduces the charging time and increases the discharging time of the battery.