USB/DC LithiumPolymer charger

Charge your single-cell lithium ion/polymer battery any which way you like with this board. Have a USB connection? No problem, just plug into the miniUSB connector. Only have a wall adapter? Any standard 2.1mm DC adapter which puts out 5 to 12VDC will work fine. If both are plugged in, the charger will automatically choose whichever has the highest voltage.

Other nice things about this charger include multiple LEDs for power & charging status, including a charging LED which will blink when the battery is full. If the charger gets too hot from high-speed charging, it will slow down the charge rate automatically. You can easily adjust the charge rate up to 1.2A or down to 100mA.

• Use USB or DC power - 5 to 12V input
• Charges one single-cell 3.7/4.2v batteries (not for older 3.6/4.1v cells) with constant current/constant voltage
• Three indicator LEDs - green for Power, orange for charging and red for error
• Charging LED will blink when the battery is full
• You don’t have to worry about heat dissipation in the charger, even when plugging in a 12V DC power jack - thermal protection inside will slow down the charge rate to prevent damage
• 2 JST connections so you can keep the battery plugged in and powering your project
• Terminal block connections galore (if you don’t like JST connectors) just solder in 3.5mm terminal blocks
• Default charge rate is about 500mA, but you can easily change this by soldering in a through-hole resistor on. The chip can do 100-1200 mA charging
• Safety timer will stop charging after about 14 hours
• The chip supports a standard 10K thermistor, which we have stuffed as a standard resistor. You can solder in a thermistor easily
• Lots of information in the datasheet for the MCP73861
• Fully assembled, tested and comes with a free JST cable