While concerns over price, availability and environmental impact have aviators worried about the future of fuel, one ultralight flyer in New Jersey has already solved that problem. Randall Fishman has been testing lithium-ion polymer battery packs to drive the prop on his ultralight trike, and he says they work great. They are powerful, smooth, sturdy, safe and quiet, Fishman claims. "The closest thing to a magic carpet ride ever," he says on his Web site. The quiet is not only enjoyable for the pilot, it improves relations with neighbors, he notes. The batteries will run for up to two hours and cost about 60 cents to charge via a standard electric outlet. However, the batteries are expensive -- $3,800 to $7,500, depending on size. The batteries are dependable and start with just the turn of a dial, Fishman says. Other advantages he cites: no handling of smelly gasoline and oil, no soot or dirt, no emissions, no vibration, no engine maintenance, no carburetor adjustments, no expensive major overhauls. Fishman flew the aircraft at EAA AirVenture in Oshkosh last week, and he has started a company, ElectraFlyer, to market the design.