The PowerCell board is a single cell LiPo boost converter (to 3.3V and 5V) and micro-USB charger in one.  The board comes with a JST connector for a single cell LiPo battery, a micro-USB connector for the 5V charge input, and selectable 3.3V and 5V ouput pins (labeled 'out'). There are also two charge pins broken out (labeled 'charge'), so you can use another 5V power source to charge the batteries, if you don't have a micro-USB cable . Project description, more information and ordering can be found at https://www.sparkfun.com/products/10300 Datasheet: http://www.sparkfun.com/datasheets/Prototyping/Batteries/MCP73831T.pdf Datasheet: http://www.sparkfun.com/datasheets/Prototyping/tps61200.pdf