Radioactive: Mobile phones - the battery conundrum

Are fuel cells the answer?

The latest mobile device developments burn through standard Li-Ion batteries like no tomorrow. So what's the solution? Futurity Media's Anthony Plewes looks at when - and if - fuels cells will arrive to save the day.

It's no surprise that longer battery life comes at the top of most users' wish lists for mobile phone features. For all the new developments in mobile applications, battery life has not kept pace. Video downloads, gaming, Wi-Fi, MMS and all the other multimedia tools are sapping battery life faster than it can be improved. In fact, if battery technology does not radically improve, 3G's future looks bleak.

One long-standing alternative to lithium ion batteries is fuel cells, which are being tested in applications as diverse as cars and laptops. Fuel cells are very attractive for mobile computing as they enable operating times of up to eight hours on a single 'fill'.

At this year's Ceatec gadget-fest in Japan, Hitachi and Toshiba were both exhibiting their latest developments in fuel cells for mobile devices, including phone chargers that used direct methanol fuel cells (DFMC) to recharge conventional batteries. Mobile operators in Japan are very interested in the technology, and both KDDI and NTT DoCoMo are said to be developing DFMC-based products.

Market research company Nanomarkets claims 2006 will be the year fuel cells take off and that the market will be worth $1.6bn by 2010. Nanomarkets asserts that the rise of fuel cells will not come at the expense of traditional batteries and that even by 2010, 80 per cent of fuel cells will be used in conjunction with traditional batteries.

Direct methanol fuel cells (DFMC) have established themselves as the market leading solution for mobile computing. They generate energy by breaking down methanol and oxygen from the air into carbon dioxide and water. DMFCs were originally developed in the early 1990s but initially found little favour because of their low efficiency and power density. However recent technological improvements have seen their power density grow dramatically and their efficiency improve to acceptable levels.

Toshiba has been pushing the same technology for MP3 players. It has developed two versions of DMFC fuel cells that can power flash and hard-disk players. The larger cell for the HDD-based player offers an operating life of up to 60 hours on a single refill. This compares very favourably with a maximum battery life around 20 hours for an Apple iPod Photo.

Fuel cells are also appearing in laptops. IBM and Sanyo Electric have been developing a prototype DFMC system for the ThinkPad notebook without the need for modification. The system will also include an auxiliary bay which will allow IBM's Ultraslim battery to be recharged.

But despite continuing enthusiasm from the fuel cell industry, many of these products are not new. Both Hitachi and Toshiba exhibited DFMC products at last year's Ceatec and the commercial launch of methanol-based fuel cell products seems to be as far off as ever. Support has even waned in some quarters; in March this year, Nokia announced that it was dropping its plans to develop a mobile phone with fuel cells. Nokia had been an enthusiastic backer of DFMC and during 2004 tested a headset powered by a fuel cell that had a 10-hour operational life on one refill of liquid methanol.

The main problem facing DFMC is that methanol is both toxic and flammable. To keep the liquid away from users, many DFMC developers use a cartridge system to dispense methanol to the system. But despite this safety measure, methanol is still banned from airplane cabins. This is a serious barrier for the technology, as business travellers are one of the biggest markets for extended battery life.

Some developers are attempting to circumvent the problems of methanol with alternative fuels. US company Medis, for example, has developed a fuel cell that uses an alkaline solution and alcohol to provide power. It has created a disposable power pack that can recharge a user's mobile phone five or six times or deliver around 20 hours of talk time. There is a fuel gauge on the pack to see how much juice is remaining. Once started the packs need to be used within six weeks and the prices are reasonable - between $10 and $20.

But DFMC remains the leading fuel cell technology for mobile computing and the majority of the industry is waiting for the ban on transporting methanol in aircraft cabins to be lifted. This should happen in 2007, after the UN passed a ruling in December 2004 on the safety of fuel cartridges. Methanol cartridges can already be transported in the hold.

Even when this key barrier is lifted, there are lingering doubts about whether fuel cell-powered mobile phones will be anything more than a niche product with novelty value. In fact many could see fuel cells as a retrograde step because they will have to buy new cartridges for each use. This will look like a return to disposable batteries rather than a new approach to recharging. Rechargeable batteries have been so popular because users can recharge them at any electrical socket - from their car, cruise ship or home.

There is no doubt that fuel cells will be very attractive in certain environments. The military, for example, is very interested in alternative forms of energy to power their increasing technology-reliant troops. Medis has already developed a refillable power pack for the US Department of Defense. It is designed to provide power to a rugged PDA that can support a 72-hour mission using only four or five cartridges. Currently military units need to carry up to 140 batteries to power a PDA for a mission of that length.

But the question still remains whether fuel cell technology will find wider application. It's all very well providing a solution for geologists to look for oil but selling a cartridge-based fuel cell system to ordinary consumers is a whole other proposition.

Anthony Plewes is a freelance journalist and director at Futurity Media.