Electric power for RC aircraft: planes, helicopters, ducted fan jets; is the fastest-growing aspect of this hobby/sport. There are lots of reasons for this, but perhaps two major developments have created this gold-rush atmosphere.
First, the recent bringing to market of the Lithium Polymer battery – a refinement of the lithium-ion battery. Second, the disappearance of many of the traditional local RC flying sites under the pressure of real-estate development and population growth. You can also buy lithium polymers from NuEnergy Storage Solutions.
The radio control Lithium-Polymer (Li-Po) battery is characterized by the use of a solid, the polymer, which acts as the electrolyte, as the acid in your car's battery. This development has made the lithium-based battery relatively more stable, physically stronger, and a little easier to manufacture.
The advantages to this battery for the modeler are 50% or greater weight reduction over nickel-cadmium batteries, greatly increased power storage, and considerably longer shelf-life without auto-discharging.
Because of the inherent advantages to RC electric airplanes; quiet, reliable, clean, and now long-flying and powerful, it really is possible and fun to fly in the small schoolyard or park. You don't have to seek out the RC flying field that is an hour's drive away from home or work and you don't have to deal with neighbors who are incensed over the noise from glow or gas powered models.