Scientists working on the possibility of electric powered manned flight at the Hamburg Geschellshafts Zentrum (HGZ) in Germany have developed a revolutionary new type of battery. The new cells are based on a substance called ‘colloidal selenium’. “Selcol” batteries, as they will be known, have a number of significant advantages. Their charge density is about 20 times higher than Lithium Polymer, offering the prospect of much reduced size with greatly enhanced charge capacity.

Edmeyer Elektronic GmbH, commercial partners of HGZ, have just launched the first Selcol battery on the market. Selcol cells operate at 25.2 volts and the new battery is approximately the same size as a conventional 3s Li-Po but with a staggering capacity of 40Ah and a discharge rating of 10C. That means that its power out is over 10kW!

Scientists at HGZ claim that this is only the beginning and that within 12 months batteries of similar size with 100Ah capacities and 25C rating could be available. Prof Wolfgang Kreitmeyer of HGZ, head of technical development for the Selcol project, happens to be the father of German ace R/C scale flyer Hans Kretmeyer. Hans is so enthused about the possibilities of the new technology, that he has already converted his quarter scale B-17 to be powered with just one of the new Selcol batteries! He says “It's just so convenient".

One battery powers all four motors operating in parallel through an ESC my father specially designed. Although the model weighs over 27Kg (approximately 60lb) we are getting flight durations of 25 to 30 minutes! Its incredible.”But the potential of Selcol technology doesn't end there. Prof Kreitmeyer says “Because of the particular quantum energy wells in ionic selenium its electrons can undertake energy level shifts under excitation from light in the wavelength range 500 to 550nm. This means that colloidal selenium is a photo-electric material like silicon. So it could be used to make extraordinarily efficient solar cells for example. We are working now at making Selcol panels that will effectively be batteries that recharge themselves in sunlight. Obviously this is very exciting.”So, could this be “goodbye to the Li-Po?" Prof Kreitmeyer thinks not until colloidal selenium can be commercially emulsified. “Once this happens we will be able to incorporate Selcol into paint, offering the prospect of a solar rechargeable high power flight battery that would be part of the aircraft’s covering”.

Its hard to see how glow engine manufacturers will be able to respond to this!