Specifications:

Charge your 2S 8.4V Li-ion battery from 5V USB.  

5V 2A in, 8.4V 1.2A out

The 2 series lithium battery boost charging board is a double link series lithium battery synchronous boost charging module with high integration and high reliability. 

The charging efficiency is 94% at the input voltage of 5V, bat voltage 8.4v and charging current of 1.2A. Charging integrates various protection functions: input overvoltage, input undervoltage, output overvoltage, output short circuit, chip over temperature, and maximum charging time of 24 hours.

Parameter function description
1. working range of input voltage: 4.6v-5.5v
2.5v/2a input synchronous boost charging
3. input adaptive charging
4. support two 4.2V batteries
5. Ed displays the charging status, and supports the display of two color lights
6. self contained trickle / constant current / constant voltage charging mode
7. 24 hour time out protection for charging
8. output over current, over voltage and short circuit protection
9. input over voltage and undervoltage protection
10. input voltage withstand voltage 13V
11. OTP over temperature protection
12. size: 28mm * 17mm