The prototype direct methanol fuel cell (DMFC) is roughly thumb size, measuring 22 millimetres by 45 millimetres (0.88 inches by 1.80 inches) and weighs 8.5 grammes (0.29 ounces).

It is "small enough for integration into a wireless headset for mobile phones but still efficient enough to power an MP3 music player for as long as 20 hours on a single two-CCs charge of highly concentrated methanol," the firm said.

Toshiba expects to commercialize DMFC for handheld devices in 2005 at yet-to-be-set retail prices.

DMFCs, which generate water and carbon dioxide as by-products, could do away with the need for recharging batteries.

Fuel cells, using hydrogen or alternative fuels such as methanol, are widely expected to replace existing lithium-ion batteries for mobile devices.

SPACE.WIRE