Wireless chargers: no more cables?

The more gadgets we have, the crazier the tangle of chargers we collect. Rhodri Marsden asks why we're trapped in a tyranny of cables, and discovers wireless technology that could finally set us free

Picture the scene: you're heading out of the door for a business trip or weekend away. You've probably packed your mobile phone, laptop, MP3 player, digital camera and hand-held games console. But how will you power this electronic array? With a slew of bulky chargers that take up suitcase space and are almost impossible to tell apart – could you differentiate between a DS charger and a Scalextric power supply?

Every new technological breakthrough brings yet more battery-powered gadgets into our homes, along with their accompanying charging devices to add to an already overflowing box of disparate black blocks. Despite the undoubted convenience of portable MP3 players, satnavs, mobile phones, eReaders, netbooks and BlackBerries, their associated chargers (which, we're told, are inextricably linked to the device and absolutely not interchangeable with any other chargers on the market lest you invalidate your warranty) represent something of a blight upon our technological lives.

To save hunting around for them we invariably leave them plugged in; the amount of energy this wastes is hotly debated, but there's no denying that it all adds up. And when you see someone panicking at a hotel and beseeching the receptionist for a spare Motorola charger while watching the last vestiges of battery life seep away, you can only shake your head sadly and think, well, there but for the grace of God go I.

It's an infuriating state of affairs. In our minds, the recharging of a battery should be no more complicated than filling up a car with petrol; just top the thing up and replace what's been used. In practice, however, making the recharging process more convenient ranks very low on the list of problems tackled by consumer electronics companies on our behalf. The charger that's packed up with your product probably isn't designed to irritate you, and it isn't necessarily designed to be unique for money-spinning reasons – but simply to get the best out of the device itself.

Unusual-looking DC connectors might be bizarrely shaped in order to fit various other electronics around them. The batteries themselves have different chemistries to ensure optimum performance for the price – nickel-metal hydride, lithium ion, lithium polymer and so on – and as the process of charging is a chemical reaction, it has to take place under certain conditions so as not to damage the battery or the device. So the best way of stopping surprises and keeping those conditions fixed is to supply a proprietary charger. "There are little subtleties that the consumer doesn't necessarily know about," says Dave Baarman from the US technology firm Fulton Innovation. "There are operational parameters, limits, some chargers are voltage-controlled, some are current-controlled – and there are all kinds of global regulatory concerns that have to be met. It becomes very difficult to design a product and not only test it with your own power supply or charger, but also test it with everyone else's, too."

In recent months, more products are appearing on the market that can recharge from a USB port on your computer via a mini-USB connector, as the USB specification allows for a 5V power supply running across it. But this can still require you to carry around your computer, its associated power supply and a spare cable for those moments you need to recharge. (Sometimes it's not even that easy, and special drivers are required to be installed on the computer in order to charge particular devices.) More than a year ago, a forum including representatives from Nokia, Motorola and Samsung agreed to dismantle the anomalies between chargers and establish the micro-USB connector as the new standard, but this decision still hasn't filtered down to the marketplace – and even when it does, many products need more than a 5V power supply to be recharged. However, when the upcoming USB 3.0 specification is introduced later this year – for which the power output has been bumped up – a greater number of devices should be able to be charged this way.

But while some efforts are being focused on reducing the number of cables, the Wireless Power Consortium is focused on eliminating them altogether and establishing a charging solution that makes discussions about connectors completely redundant. Over the past five years there have been various prototypes and demonstrations of how wireless power might work, but its successful introduction relies on devices containing compatible circuitry to receive power and deliver it to the batteries – so, again, there's the issue of establishing an agreed standard. The WPC has recently launched such an initiative, and Fulton Innovation (one of the eight companies in the consortium) sees this as an important moment: after many years of innovation, wireless power units can now be made small, relatively inexpensively, and with the ability to cope with different kinds of battery. "That's why we call our solution 'intelligent wireless power'," says Baarman. "The unit communicates with the device; the device tells us what its limits are, how it wants to run, how it wants to be charged, and it dynamically adjusts." With Baarman's "eCoupling" prototype, which was demonstrated at last week's International Consumer Electronics Show in Las Vegas, you can charge a bluetooth headset, a 3G iPhone and a toy helicopter – all of which have different power requirements – by placing them on its surface. "When you drop your device on it," he says, "there's a magnet that pulls it to the correct place, and a light underneath turns on to show you that it's charging, and charging properly."

Baarman reels off a list of benefits of the technology. "Toys for children under a certain age have battery covers that are screwed in place so that the child can't get small parts out; charging or replacing those batteries means getting a screwdriver out. With wireless power you just pop it on top of the unit. And we've done work with remote controls; instead of containing a battery we've given them a super-capacitor. And our units can charge those in 10 seconds, which subsequently gives four days of charge – it's incredibly convenient."

With chargers bundled with every device, there's no doubt that companies have an associated income stream that will be dented heavily by the introduction of wireless power. But Baarman believes that the benefits to the public will cancel out resistance from the industry. "There's a significant consumer outcry about this – people asking why they need all these chargers," he says. "And our device is being received in such a positive and powerful way that its introduction has to be good for the industry as a whole."

Pull the plug: New ways to boost your batteries

Walking

American scientists devised a proof-of-concept charger last year (in other words, they demonstrated that it could work in principle) when they produced a knee brace that worked in a similar way to regenerative brakes in battery-driven cars, outputting an average of 5W during a slow stroll. That's sufficient power to charge up 10 mobile phones. A knee brace isn't a particularly sexy idea, granted, but it's a great example of passive charging that doesn't require any extra effort on our part.

Dancing

Mindful of the problems faced by mobile phone users when they're stuck in a field in the middle of Somerset, mobile network Orange commissioned research into a portable kinetic energy-driven charger that would allow us to replenish the dwindling reserves of a battery by jiggling arhythmically to the sound of Franz Ferdinand. A device called Dance Charge was the result – 180g, the same size a pack of cards, and attached to your bicep by means of Velcro. Prototypes were built for testing at Glastonbury; it hasn't reached the market as yet.

Wind

The same company behind Dance Charge was also given four weeks to design a working prototype for a wind-charged device; the result – Recharge Pod – could be mounted on a tent and had the capability of charging 100 phones per hour, although one assumes that this figure depends on there being rather more than a gentle breeze blowing. Again, the company – gotwind.org – is still looking for partners to get its design into the shops. It demonstrated the Recharge Pod Mk2 at the Consumer Electronics Show in Las Vegas.

Cycling

Motorola announced its plans to release a mobile phone charger that was pedal powered back in 2007. The idea behind the device was to aid potential customers in developing countries. "For people living in emerging markets, energy is a scarcity," Motorola chief executive Ed Zander said. "In south-east Asia, rural China and Latin America, we can actually put this in, hook it up and charge this device while we are riding a bike." Another designer, Oscar Lhermitte, has developed a similar device too – see www.oscarlhermitte.com for details.