Adafruit Micro Lipo w/MicroUSB Jack - USB LiIon/LiPoly charger - v1 [ADA1904]

This lipo charger is small and easy to use. Can be mounted easily into any project. Plug it in via any MicroUSB cable into a USB port and a 3.7V/4.2V lithium polymer or lithium ion rechargeable battery into the JST plug on the other end. You can purchase a Lithium Ion Battery - 3.7v 2000mAh here or a 1200mAh Lithium Ion Battery here.There are two LEDs - one red and one green. While charging, the red LED is lit. When the battery is fully charged and ready for use, the green LED turns on. 

The MINI Lipo w/Mini-B USB Jack - USB LiIon/LiPoly charger can be found here

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 charge current is 100mA by default, so it will work with any size battery and USB port. If you want you can easily change it over to 500mA mode by soldering closed the jumper on the front, for when you'll only be charging batteries with 500mAh size or larger.