Lithium ion secondary battery charging method and device

摘要

A method of reducing the deterioration of lithium ion or similar secondary batteries, caused by over-charging, uses a switching device which delivers the charge alternatively in load and rest periods. The charging system comprises a DC source (1), a switch (SW1) and a controller (2). The DC energy source (1) changes the mains alternating current of 100 Volts to a continuous current of the suitable voltage for charging the batteries (B). The control device (2) switches the switch (SW1) in and out to give the batteries alternating charge/rest periods. Within the battery array (3) are two batteries in series (B) an over-charge protection switch (4) containing a difference amplifier (5), a reference voltage (E), a constant current source (6) and an inverter (7). This operates the switch (SW1) if the voltage reaching the batteries (B) exceeds the reference (E).