Lithium-Ion Polymer (LiPo) batteries are a favorite of ours. Very light weight and some of the highest energy densities available.

In this project, we’ll create a wearable LED Crystal Crown using a simple circuit made of 7x Super Bright White LEDs wired in parallel and powered by two coin cell batteries wired in series.

The SparkFun Adjustable LiPo Charger is a single-cell lithium polymer (LiPo) and lithium ion battery charger.