There are now 110 consumer electronics products that are authorised by the Wireless Power Consortium (WPC) to carry the Qi logo. One of the latest is Nokia's flagship Lumia 920, due to be released later this month.
As the Qi product ecosystem approaches 10million global units, could the technology be nearing a tipping point? WPC chairman Menno Treffers claimed the technology has already tipped in Japan and its forthcoming integration in phones in the US and Europe looks set to make it available to consumers on a wider scale. "It's become a standard feature of phones in Japan and that has triggered the adoption of Qi in restaurants and coffee shops – places where people sit down for a while," he said. The benefit of wireless charging for mobile phones in these locations is that users can put their device down on their table to charge and pick it up again when they leave. "It's a significant step in convenience," said Treffers. "When we get this in the hands of consumers, there's no turning back – consumers will want it." As anyone who has charged an electric toothbrush will understand, wireless charging through magnetic induction is not new. "It's a very old technology," said Treffers. "It's basically a transformer – high school stuff – with two coils." An alternating current in the transmitter coil generates a magnetic field, which induces a voltage in the receiver coil when they're close enough to each other and charges the battery. "The difficulty is in making sure you control the power levels," Treffers added. The receiver has to be in control of the power coming in or it will damage the battery. In order for this communication between the receiver and transmitter to take place safely and reliably, there has to be a standard. The Qi interface is designed to provide interoperability, design freedom, product differentiation as well as access to essential patents. "Without an interface standard, the market will never take off," observed Treffers. He believes that if the chargers for each phone brand are different, consumers will not be willing to pay more for them. Plus, companies that work with infrastructure products – such as automotive – will not install the chargers if there isn't a unifying standard. "They will choose a standard and they will stick to it," said Treffers. "They will choose the standard that has the highest market traction." Of course, the Qi standard doesn't just apply to mobile phones. Treffers claims it could help make it possible to design television and video game remote controls without batteries. Cameras are another example. "With wireless charging, you can seal cameras so they become watertight, dustproof – there's no connector anymore." Power can be transferred wirelessly and so can data via WiFi or Bluetooth. This could apply to any device subjected to harsh environments. "Or for medical equipment, where it's necessary to clean and disinfect products," he suggested. Treffers said transfer efficiency for the technology is around 70%, but that companies can invest in more sophisticated components and coils to reach about 80%. "Efficiency is only a small part of the total picture," he noted. "It's more important to look at total energy consumption of the solution." Standby power is a large part of the equation – many conventional chargers are often constantly powered on. As wireless chargers can detect whether something is actually on them, standby power is very low. Treffers proposes that if one wireless charger replaced several different power supplies, the user would break even in terms of efficiency. It's also worth considering that users might not choose a single core, more efficient phone with lower functionality rather than their quad core smartphone. Treffers believes this is where the real power consumption issues lie, not in transfer efficiency, so this issue won't impede the progress of wireless charging. More power is the first objective for the future. Existing Qi chargers achieve 5V, but Treffers is looking at between 10 and 15V for increased convenience. Outside of the standard, he sees the ecosystem of companies that make products for the interface starting to develop new solutions. For example, devices that optimise size, positioning and are capable of charging multiple products simultaneously. "There is a lot of innovation in products around the standard," he said. "So you'll see a lot more choice for consumers." New products could combine charging with other functionality, such as audio docks with no connectors. "The market for these accessories and docks is enabled only by standards," said Treffers, citing how Nokia, Samsung, HTC and Motorola are all making Qi products. Once power is achievable without connectors, devices can be completely wireless – essentially this standard could be the gateway to enabling many new wireless solutions in electronic devices. If the technology has been around for a while, why is it only coming into play now? Treffers said many companies experimented with it and found they could make it work, but consumers weren't willing to pay for it. "That's why the companies that tried it came together in the WPC," he said. "The only way to make this work is to make it into a standard – that's the way to get it to market." Treffers also believes battery technology hasn't kept up with mobile phones, so the convenience of wireless charging pads will allow consumers to use the full features of their devices without worrying about draining the battery. "The time is right for this," he concluded.