All important green light should mean longer chargesThe US Department of Transportation (DOT) has ruled a new fuel cell can be taken on airplanes, partly clearing the way for commercial acceptance of this alternative to standard laptop batteries. Onboard use of fuel cells - which will let notebook computers run three to 10 times longer without a recharge - has been questioned because they contain methanol, a flammable liquid. But the DOT said a cell designed by start-up PolyFuel can ride in airplane cabins when it emerges commercially because it contains a relatively low concentration of methanol, according to Jim Balcom, PolyFuel's CEO. Fuel Cells are viewed as one of the likely 'big' changes that will alter notebook architecture in the next few years. The replaceable, or refillable, fuel cartridges initially will be able to power laptops two to three times longer than standard laptop batteries, which now peter out at between two and four hours. Eventually, fuel cells will provide a charge 10 times longer than batteries, according to various sources. Many analysts have viewed approval from transportation authorities as a necessary step to commercialisation. If fuel cell powered notebooks can't be taken on planes, few people will buy them. It also helps psychologically. "It is not surprising that people are hesitant, [but] once it gets approved, obviously it is viable," said Matt Sargent, notebook analyst at market research firm ARS. "There is a clear need for progress in the battery space. It has been one of the hard spots for the industry."