Apple has become a member of the Wireless Power Consortium (WPC), the same group that has developed the “Qi” wireless charging standard for the past nine years. Apple’s membership and a potential future iPhone that supports the Qi standard may once and for all establish Qi as the winner in the battle for supremacy of the wireless charging standards.
Competing Wireless Charging Standards
The Qi standard was one of the first wireless charging standards to be adopted in mobile devices. However, at the same time, the PMA standard was being promoted by Powermat and other big companies. This created some confusion in the market and mostly froze many smartphone makers’ plans to adopt a standard until the wireless charging choices became more clear.
The introduction of the “next-generation” Rezence standard by the Alliance for Wireless Power (A4WP) further complicated things. The Qi and PMA standards used “inductive” charging, which basically required the power transmitter and the power receiver of the phone to be on top of each other.
Rezence worked via “magnetic resonance,” which meant the device receiving the wireless power didn’t have to sit exactly on top of the transmitter--it could be in the general area. However, the closer the transmitter and the receiver would be to each other, the more efficient the power transfer would be, and the faster the device would charge.
Powermat and the A4WP eventually decided to join together and create the “Airfuel Alliance.” The new alliance has had mostly the same members as the the WPC, with one notable addition: Intel.
However, wireless charging isn’t necessarily something everyone wants for their notebook or PC, and Intel isn’t a major player in the mobile market. Therefore, Intel’s membership may not count as much in terms of convincing others to go with Airfuel’s wireless charging standard.
Apple Backs Qi Wireless Charging
With Apple now part of the WPC and backing Qi wireless charging, we’ll probably see many more smartphone manufacturers adopt Qi wireless charging for their devices, because they know the standard will have a much higher chance of becoming mainstream than it did before.
Apple was rumored to have partnered with Energous, the company developing the long-range “WattUp” wireless charging technology that uses radio waves in the 5.7GHz spectrum to transmit power. The technology can charge a device up to 15 feet away from the transmitter, but the power will be reduced to 4W compared to a claimed 16W when the device is less than five feet away.
Apple may still one day decide to use this technology for its devices, but until then, it probably made more sense to go with the Qi standard that many companies have already adopted. It’s also possible that Qi inductive wireless charging is still the most efficient way to charge a device in the real world, among all the existing wireless charging technologies, because of how the power receiver is required to be close to the transmitter.
However, even Qi charging isn’t as fast and efficient as charging by cable, which has minimal power loss. The comparison is even more drastic when you consider the recent advances in “quick charging” technology and the fact that USB Type-C ports now allow for significantly more charging power (up to 100W). This is one of the main reasons why Google decided to drop wireless charging in favor of the fast charging of USB Type-C chargers in the Nexus 6p and Nexus 5X.
Apple is also rumored to sell its wireless chargers as an option for future iPhones, which seems to make sense considering most people may still prefer to charge their devices as fast as possible. Only some people, at least initially, may prefer the convenience of wireless charging over the fast charging of their regular chargers.
Even with Qi charging, you still have to put your charger on top of the transmitter or very close to it (as it now supports resonant charging as well). Therefore, the Qi wireless charging may not be that much more convenient than using a regular charger.
One day we may all have all of our devices and electric vehicles continuously charge from transmitters all around us (in a safe way) using technologies such as Energous’ WattUp and Ossia’s Cota, but we may have to wait several more years for that to happen.
