Abstract: An active charge equilibrium system for lithium battery pack consists a lithium battery pack composed of connecting multiple cells in series, including a multiplex module, control module and multiple equilibrium control module, which each segment of the cells are connected to the multiplex module in sequence, a voltage signal is converted into a digital signal via the control module to compare the voltages of the cells and select the cell with lower voltage. Further, the control module enables the equilibrium control module corresponding to the cell with the lower voltage to work. A pulse width modulator adjusts the output pulse width according to output current and voltage signal from a signal feedback module for controlling current and voltage to charge the cell. As the voltage of the cell reaches a constant current first and a constant voltage second, the control module turns off said equilibrium control module.

Abstract: An active charge equilibrium system for lithium battery pack consists a lithium battery pack composed of connecting multiple cells in series, including a multiplex module, control module and multiple equilibrium control module, which each segment of the cells are connected to the multiplex module in sequence, a voltage signal is converted into a digital signal via the control module to compare the voltages of the cells and select the cell with lower voltage. Further, the control module enables the equilibrium control module corresponding to the cell with the lower voltage to work. A pulse width modulator adjusts the output pulse width according to output current and voltage signal from a signal feedback module for controlling current and voltage to charge the cell. As the voltage of the cell reaches a constant current first and a constant voltage second, the control module turns off said equilibrium control module.