The USB LiPo Charger is a basic charging circuit that allows you to charge 3.7V LiPo or Li-Ion single cells at a current of 500mA or 100mA. It is designed to charge single-cell Lithium-Ion or Lithium-Polymer batteries. Check the datasheet below to see if it will work with your battery.
The board incorporates a charging circuit utilizing a Microchip MCP73831T, status LED, selectable solder jumper for 500mA or 100mA charging current (in 500mA position by default), charging status LED, USB input, mounting holes, two pre-installed JST connectors for SYS OUT and BATT IN, and a barrel jack connector.
The SYS OUT allows you to connect the charging circuit directly to your project so that you won't need to disconnect the charger each time you want to use it.
Both SYS OUT and BATT IN are accessible also via through-hole pin pads as alternatives to the JST connectors.
The power input can come either from the USB or the power jack. If using USB, make sure your USB port can supply 500mA if using the board's default 500mA setting; this is the maximum possible current in the USB specification, so many USB ports may be set to a lower output. Input to the power jack should be between 4.75V and 6V. The jack has 5mm outer diameter with a 2.1mm center-positive pole.
Charging currents other than 100mA or 500mA (between 15mA and 500mA) are possible by cutting both jumper traces and installing a resistor of your desired rating into the PROG pads provided on board. Never set the charging current higher than the equivalent mAh capacity (1C) of your battery! In other words, with this board at the default 500mA setting, only connect batteries with a capacity of 500mAh or more.
Use the following equation if you want to set a custom current:
Thus, to set to 400mA, you would need to add a resistor value of 2.5kΩ to the PROG pins (in addition to making sure neither the 100mA or 500mA solder jumpers is connected).
The board has through-hole pads for you to install a larger LED for the charging indicator, if you prefer to have a 3mm or 5mm LED instead of the surface-mount LED that comes on the board.
USB Li-Poly Charger Resources
Optional Recommended Products for this Item
|USB 2.0 Cable, 6ft. A-Male / Mini-USB (5-pin) B-Male||+|| US$6.00|
|2-pin Female JST Connector, 2mm pitch, with 5-inch Wires||+|| US$0.95|
|Screw Terminal to Male DC Barrel Jack Adapter, 2.1x5.5mm||+|| US$2.95|
|Polymer Lithium Ion Battery, 850mAh, JST Connector||+|| US$9.95|
|Polymer Lithium Ion Battery, 2000mAh, JST Connector||+|| US$16.95|
|Polymer Lithium Ion Battery Pack, 6Ah, JST Connector||+|| US$29.95|