such as SparkFun Sunny Buddy, Adafruit Universal Solar Charger, and DFRobot Solar Lipo Charger, on your favorite maker site or on Amazon. For your third component, you need a battery. This is what ...

Luckily, [Paul] sent in a great tutorial on building a LiPo charger that works over USB. The board [Paul] came up with is incredibly small – just barely larger than the USB plug itself.