Qi wireless charging standard emerges victorious; adoption rapidly increasing
The history of technology is littered with the remains of abandoned standards. Betamax, Mini Discs and HD DVDs, among others, are examples of standards that have been left by the wayside after a protracted battle when a competing technology gained majority market share (VHS, MP3s and Bluray respectively were the winners here).
Consumer adoption of these technologies is often hampered by these format wars until one remains victorious. Wireless charging has arguably failed to gain widespread recognition, despite being on the market for several years now, as a direct result of confusion about which format would ultimately win out.
In recent years, the war has effectively been whittled down to two standards: Rezence, which is backed by mobile chipmaker Qualcomm, and Qi which was created by the Wireless Power Consortium (WPC), a loose alliance of technology companies large and small.
While Rezence has some technical advantages (it can work through metal and devices do not have to be placed as precisely to draw a charge), the 6.78 MHz frequency at which it operates is more prone to causing electromagnetic interference with other devices than Qi and is less power efficient.
Qi was also backed by some of the most prominent smartphone makers, probably the most important device for mass adoption of the standard.
Nowadays there’s not a single Rezence-compliant smartphone on the market, while interest in Qi is growing rapidly. Even Apple joined the alliance recently, sparking rumours that wireless charging will be included in the next iPhone.
“At this moment, there’s not much of a battle,” said Menno Treffers, chair of the WPC. “The battle between standards is fought through market share of technology. There’s no adoption of 6.78 MHz in any mobile phone, not in any vehicle, not in any home charger.
“I think the perception of a battle [between standards] may continue for a while because it’s not up to us to declare it over. But it is not something that plays a big role for us anymore.”
Treffers believes Qi has now reached the mass market volume sufficient to see the platform thrive. About 160 million smartphones per year are now sold with the technology along with 50 to 80 million chargers.
These figures are currently growing by about 40-60 per cent a year and with Mobile World Congress just around the corner, a further batch of compliant devices is anticipated to arrive in the next few weeks.
When asked about whether the iPhone 8 would have Qi, Treffers was coy about making any predictions.
“They don’t tell us and the members don’t tell each other about what their product plans are,” he said. “What’s important for us now is that all the major mobile phone companies, the ones with the highest volume, are talking together about making their products compatible. What this actually means for products and when, we don’t know.”
Apple has already used components in Qi-compliant products like the Apple Watch, but the specification has been altered slightly to make it proprietary so that it will only work with an official Apple cradle.
Some of the first Qi-enabled devices came out in 2012 including Google’s flagship Android phone at the time, the Nexus 4, yet the technology has yet to reach ubiquity even after five years.
“If you introduce something like wireless charging, the components are expensive, consumers don’t know much about it so they don’t value it very much, and that means that you can only in practice put it into products that are high end,” Treffers said.
“When you get a little bit of volume the components become a lot cheaper and it becomes more affordable. You get more exposure, companies start to advertise it. At the WPC we don’t have a budget that we can do consumer advertising with. It has to come from companies that are advertising their product and using the feature to explain it.
“That only happens when there are a sufficient number of people to understand the feature. Last year you could see that transition happening, some companies began advertising it as a feature and car manufacturers even featured it on TV adverts.
“So although for people working on it, adoption appears slow, it is the normal pattern. Now that we have this mass market volume, adoption becomes more automatic. I expect in the coming year to see many new phones come out supporting it.”
But even with this success, Qi is not standing still and is working on improving the specification. When it was first created in 2010, chargers would output only around 2.5W. This was quickly followed by 5W, which is the standard for mainstream chargers, and last year Qi was given a 15W extension.
The user experience is also being worked on. Wireless power transmitters are set to be released that use a coil array so devices don’t have to be positioned as precisely.
“That’s the kind of innovation that is happening,” Treffers said. “Manufacturers have a range of options, they can go for low-cost charging pads with a single coil or a make it a little bit more expensive with better user experience and more charging coils.”
But it’s not just device manufacturers that are getting on board, Qi’s increasing success can be measured by the number of companies that aren’t traditionally technologically orientated that are embracing the standard.
Ikea for example started releasing tables and lamps with charging built in as far back as 2015. While McDonald's is bringing Qi to its restaurants, with future revamps set to include charging capability in its tables, coffee shops like Starbucks are also jumping on the bandwagon and all of the major car manufacturers are including Qi in the dashboards of at least one or more of their models.
At the WPC’s recent showcase in London, prototype laptops were shown being powered by a Qi-enabled table, technology that is expected to be made available to consumers in the next year or two according to a representative.
When asked about the holy grail of wireless charging, with a device drawing power from the environment around it without needing to be placed on a specific charging matt, Treffers said that this was not really possible as exposure to such high levels of transmitted power would not be safe for humans or allowed within regulatory boundaries.
But while smartphones require several watts to charge at a reasonable speed, some devices only need milliwatts to operate, a power level that could be safely transmitted over the air.
“The real market for this kind of application is Internet-of-Things sensors,” he said. “Where you don’t want to have to replace the batteries.”