NTT DoCoMo has developed with a Japanese venture company a fuel-cell recharger for cell phones and will work with the same company on a compact fuel cell for use in cell phones, it said Friday.The recharger was developed with Aquafairy, a start-up spun out of Nitto Denko, to work on fuel cell technology.The device is a quarter the size and twice as powerful as a fuel-cell recharger NTT DoCoMo unveiled in July last year that was developed with Fujitsu Laboratories. The new recharger has an output of 2 watts and measures 24 millimeters square, is 70 millimeters\u00a0long and weighs 45 grams.It\u2019s a polymer electrolyte fuel cell (PEFC) in which water is injected into a cartridge and converted to hydrogen by a catalyst. The hydrogen is sent to an anode where the ions and electrons are separated and the electrons flow to the cathode, thus creating electricity.Fuel cells small enough for use in cell phones are a goal of many wireless carriers. The added functions and features on modern handsets suck up available power quickly, meaning users are faced with recharging their phones more often. A fuel cell within a phone could be recharged almost instantaneously, eliminating the need for users to plug the phone into an electrical outlet for hours to charge a dead battery. However, engineers face a big challenge in getting fuel cells small enough to fit inside a cell phone.\u00a0Hence the initial focus on rechargers.The new device can recharge a cell phone in about the same amount of time as a conventional AC adapter, NTT DoCoMo said.Looking further ahead, the two companies have also agreed to work on development of a fuel cell for\u00a0third-generation cell phones.The prototype fuel-cell recharger will be displayed at the Wireless Japan show, which takes place in Tokyo next week from Wednesday to Friday.-Martyn Williams, IDG News Service (Tokyo Bureau)Check out our CIO News Alerts and Tech Informer pages for more updated news coverage.