The days of rushing to get your work finished before your laptop runs out of power could soon be at an end.
Fuel cells could replace batteries
Japanese electronics giant NEC has unveiled a laptop computer that has a built-in fuel cell that can keep the machine running for far longer than battery-driven models.
Early versions of the fuel cell can keep a laptop going for five hours.
Within two years NEC said running times between fuel cell refills could be 40 hours or more.
The small fuel cell is powered by 300 cubic centimetres (half a pint) of methanol and uses a catalyst to break this down into oxygen and hydrogen and generates heat and power as by-products.
On its own, the fuel cell weighs 0.9 kilograms (1.98 pounds) but adds 2 kg (4.5 lb) to the weight of a laptop when built-in.
NEC said it expected the first laptops containing the fuel cell to go on sale in 2004. The company estimates that the lifetime between refills for these early versions will be about five hours.
By 2006 it expects the fuel cell to be much more efficient and run for almost 40 hours without needing a top-up.
Computer firms and laptop makers are working on ways to make the inner workings of mobile computers much more power efficient.
However, many feel that only fuel cells will be able to make a significant difference to the time they can work between recharges.
NEC is not alone in working on fuel cells for mobile devices. Motorola is known to be developing them to power mobile phones and Toshiba showed off a prototype device at the 2003 Cebit technology fair in Hanover, Germany.