Hitachi has co-developed a prototype direct methanol fuel cell (DMFC) for use in mobile electronics products and plans to launch the product with a compatible PDA (personal digital assistant) in 2005.

The Tokyo company developed the fuel cell with Tokai, which is a major producer of disposable lighters and aerosol dispensers.

Direct methanol fuel cells mix methanol with air and water to produce electrical power.

Hitachi's prototype uses a methanol concentration of around 20 percent, although the company plans to raise this to around 30 percent by the time it becomes a commercial product, said Koichi Nemoto, a spokesman for the company's research and development laboratories in Hitachi City, Ibaraki prefecture.

The prototype fuel cell is a cartridge type around 1 centimeter in diameter and between 5 centimetres and 6 centimetres in length, said Nemoto. Hitachi considers this size, which is similar to that of a AA battery, as about the right size for commercial use and so won't be working on changing the dimensions by a large amount.

In making the announcement Hitachi becomes the third Japanese electronics company to disclose plans to commercially produce DMFCs.

NEC has demonstrated a prototype unit for use with notebook personal computers that it says will become a commercial product sometime in 2004. The prototype can deliver enough power for around five hours of use and the company's mid-term goal is to develop and sell a 40-hour unit by the end of 2005.

Toshiba has developed a DMFC that is intended to be used as a handheld charger for batteries for mobile electronics products. At present research has not progressed to the stage where a fuel cell small enough to fit into a portable device is within grasp so Toshiba hopes its charger, expected to be commercialised in 2005, will be the next best thing.