This utility model discloses a protection circuit for two
lithium batteries, including a battery protection
chip SC5550ABBE. The positive and negative terminals B+ and B- of the two
lithium batteries are connected for charging via positive and negative charging terminals P+ and P-, respectively. A charge /
discharge MOSFET is connected in series on the negative charging line. The battery protection
chip SC5550ABBE is connected to collect the
voltage of two cells from the two
lithium batteries in each string and controls the on / off state of the charge /
discharge MOSFET. This utility model's two-string
lithium battery protection circuit uses the highly integrated lithium-
ion or
lithium polymer battery protection
chip SC5550ABBE. This chip provides
overcharge, over-
discharge,
overcurrent, open circuit, and overtemperature protection for the
battery pack, as well as
equalization functions, and supports cascading. By using this protection chip, the safety and reliability of lithium batteries can be effectively improved, and the battery life can be extended.