2pcs Micro USB LiPo Battery Charger Board 5V 500mA with Battery Protection JST Socket with LED Indicator Charging Rate Adjustable Automatic Power-Down
Specification: Input volate:DC5v Size: 21.5mm  20.5mm (0.850.81in) Charging
rate: 500mA Thermal Regulation Temperature Range: -40°C to +85°C Applications
Lithium-Ion/Lithium-Polymer Battery Chargers Personal Data Assistants Cellular
Telephones Digital Cameras MP3 Players USB Chargers Robots and motor drivers
Package Includes: 2Micro usb lithium battery charging board (battery not
included) 2cable
 
Product Features
  

         
This is a lithium battery charger equipped with a battery charge controller IC MCP73831T-2ACI/OT, the input charging connector uses Micro USB.
         
Automatic Power-Down:There is an LED indicator on the charging board. When charging, the led indicator will be lit, and when the battery is fully charged, the led indicator will go out.
         
The default charging rate of the charger is 500mA. If the battery is charged with a current that exceeds the battery charging current specification, it will cause the life of the lithium battery to decrease. So you can add some resistors on R1 (this would require cutting a trace) or replacing the surface mount resistor with a higher resistance value.
         
It is for charging 3.7/4.2v single Lithium Ion/Lithium Polymer batteries
         
Plug the Micro USB cable into the USB port of the charging board, and insert the lithium battery into the JST port on the other end