Features 【High Quality Material】: The lithium battery charger module is made of high-quality electronic components, which is durable, stable in performance and reliable in use. 【Multi Protection】: This li ion battery charging board provides protection functions such as overcurrent, overvoltage, short circuit, and overheating to protect the lithium battery from burning out during charging or discharging. 【Easy to Use】: The layout of the charger discharge module is reasonable, and the wiring is easy to use. Suitable for 3.7V or 4.2V lithium battery, with a discharge efficiency of up to 96%. 【Widely Application】: Our lithium battery protection board is widely used in mobile phone charging, alarm clocks, driving recorders, work lights and other fields. 【Service Guarantee】: We provide 24-hour after-sales service, if you have any questions about the charge protection board, please feel free to contact us, we will try our best to solve your problem. Specification: Charging voltage: DC 4.5V-5.5V (DC 5V recommended)  Charging current : 0-2.1A  Charging quiescent current : 100uA  Full voltage: 4.2V+-1%.  Discharge current: 0-2.4A;  Discharge quiescent current : 50uA  Discharge efficiency: up to 96%  Output voltage: 5V  Output current: 0-2.1A;  Ambient temperature: -20℃-85℃  Protect function: OCP, OVP, SCP, OTP Wiring: GND connect to battery negative VIN connect to battery positive VOUT Connect to the positive output+ GND Connect to the positive output- Package List: 1 * Lithium Battery Charger Module Package List