How to power ever more juice-sapping portable devices is a problem currently perplexing hardware designers. One possible solution could be fuel cell batteries, which offer longer life and don't need recharging.

Until now many manufacturers have talked about fuel cells, but Toshiba is first off the blocks with a prototype DMFC (direct methanol fuel cell) for portable PCs.

This prototype combines the benefits of fuel cell with the small form factor required for use in a portable computer. It currently offers an average output of 12W and a maximum output of 20W, and provides a claimed five hours of battery life with 50cc of fuel.

In order to cut down the size of the fuel cell Toshiba had to reduce the amount of water required to dilute the methanol, which allowed it to make the fuel tank to one tenth of the size previously required. It also developed a new material that allowed it to create smaller cells.

The fuel cell is able to monitor the power required by the PC so it can deliver the optimum amount at any given time, and in idle times store excess energy for use at a later time.

Toshiba has used the same electrodes found in lithium-ion batteries so it can connect directly to a notebook in the same way as a traditional battery.

The company hopes to bring its fuel cell batteries to the market in 2004 and will be showing off the prototype at the CeBit expo in Germany later this month.