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.For use with Adafruit Lipoly/LiIon batteries only! Other batteries may have different voltage, chemistry, polarity or pinout.