A new technology seems set to make batteries more efficient.

The fuel cell technology will offer a “quick fix” for dead or dying mobile phone batteries. It will debut in Japan in 2007, Japan's two biggest mobile communications carriers said at the Wireless Japan 2005 Expo.

DMFCs (Direct Methanol Fuel Cells), which typically work by mixing methanol with air and water to produce electrical power, have long been promoted as an alternative to the lithium ion batteries used in notebooks and other portable electronics gear. DMFCs are useful because power can be instantly provided by inserting a fuel cartridge recharger, developers say.

A number of Japan's biggest consumer electronics companies have been developing DMFCs, but prototypes shown to date have been too big and bulky or not capable of producing enough power to be commercialized.

Set for change

NTT DoCoMo and KDDI, Japan's number one and number two mobile communications carriers, plan to have fuel cell rechargers for mobile phones in shops in 2007.

Japan's mobile phone vendors have spent years trying to get the battery life of 3G (third-generation) mobile phones to match that of the country's 2G digital phones. Next year a new problem will hit vendors as they put power-hungry digital TV receivers into phones as the country's digital TV network goes nationwide. The antennas will knock usage time back down and that's where DMFCs will help, vendors and carriers say.

In DoCoMo's case, the company has a prototype charger on display at Wireless Japan. It is developing the charger with Fujitsu Laboratories and the device is near to completion, said Kazuhiko Takeno, a manager at the company's Technical Support Group.

The recharger, which is a cradle design, is slightly bulky at 15 centimetres by 5.6cms by 2.5cms, and weighs 190 grams. But it works, and carries enough power to recharge a mobile battery three times.

Multi-track development

Fuel-cell technology also appears viable for KDDI's customers, according to Youichi Iriuchijima, an assistant manager at the company's IT Development Division.

At last October's Ceatec Japan 2004 exhibition, Iriuchijima showed prototype rechargers from Hitachi and Toshiba, saying improved versions would be in the shops in 2006. That schedule has now slipped to January 2007.

The designs shown last October were only mock-ups and displayed under glass. This year's versions both actually produce electricity. To prove the point, he took a vial of diluted methanol and plugged it into the side of the Hitachi recharger, and the mobile phone it was supposed to power immediately sprang into electronic life.

The two working prototypes take a different approach to Fujitsu's models, however, being boxes that use cords to feed power to the mobile phones.

The Hitachi version offers two recharging options: A 2ml vial of fuel, which snaps into the side of the device, can power a mobile phone for about an hour, while a 15ml vial gives about five hours of power, Iriuchijima said.

The Toshiba version is bigger, but a 20ml vial of fuel is capable of delivering 20 hours of power, he said.

KDDI was also showing even smaller versions of DMFCs that are integrated into mobile phones. These, however, were mock-ups and they were not producing electricity.

Shrinking DMFCs into sizes that can be fitted into mobile phones and having them good enough to sell will take about three years, Iriuchijima said.

"Replacing lithium ion batteries with same-size fuel cells is very difficult technology," he said.

For DoCoMo, such fuel cells may not be available until the end of the decade, Takeno said.