USB LiIon/LiPoly Charger - v1.2 is a Lithium Ion and Lithium Polymer battery charger based on the MCP73833. It uses a USB mini-B for connection to any computer or 'USB wall adapter'. Charging is performed in three stages: first a preconditioning charge, then a constant-current fast charge and finally a constant-voltage trickle charge to keep the battery topped-up. The fast-charge current is 500mA by default, but is easily adjustable from 100mA up to 1000mA by soldering a through-hole resistor on-board.
USB LiIon/LiPoly Charger - v1.2 is great for DIY projects because it has 3 indicator LEDs - one for power, one for charging status and a third that indicates when charging is complete. Keep the battery connected to the charger and pass power through the additional JST connector.
Note: USB LiIon/LiPoly Charger - v1.2 is for use with Adafruit Li-Poly batteries only. Other batteries may have different voltage, chemistry, polarity or pinout.
Adafruit Web Site: https://www.adafruit.com/products/259