When going portable with your electronics projects or diving in to RC hobby you eventually have to deal with batteries. No secret that best what is available today is lithium batteries. They come in many flavors. Why use lithium battery instead of alkaline or NiMh rechargeable? The short answer is – energy density. Lithium Ion batteries can store large amount of energy comparing to its weight and can give out large currents. This technology made it possible to enjoy long and powerful RC model (like quadcopter) flights. To achieve same results with NiMh it looks almost impossible due to weight and low current output. Lithium battery technology is constantly improving as different chemistry is used. You can find lots of info about different chemistry of Lithium Ion batteries so we won’t be getting into this.