TP5100 Lithium 18650 Battery Protection Board Rechargeable Charger Buck Module [ElectricA]

Needless to say, the main part of the module is the TP5100 chip from Top Power ASIC. According to its datasheet, TP5100 is a step-down switching double 8.4V / 4.2V single lithium battery charge management chip with built-in input overcurrent protection, under-voltage protection, over-temperature protection, short circuit protection, battery temperature monitoring, and reverse battery protection. 

Dual-cell 8.4V/Single-cell 4.2V
Input voltage: 5V-15V DC
Switching frequency: 400kHz
Red LED: Charging indicator
Blue LED: Full charge/ No battery indicator
Both Red/Blue LED off: VIN very low/High-temperature shutdown
No need for external anti-backflow Schottky diode
Onboard solder jumper to set 1S/2S mode
Option for an external bicolor LED