A4WP Delivers Spec for Charging Multiple Devices Up to 50 Watts

The Alliance for Wireless Power (A4WP) announced at Computex 2014 in Taipei Wednesday that its Rezence technology is the first wireless charging standard to deliver a specification for multi-device charging up to 50 watts. That expands the wireless charging capability beyond smartphones to include tablets, laptops and other consumer electronics, a direction the group of wireless charging companies outlined at the International Wireless Power Summit late last year (CED Dec 9 p1).

To support upcoming “rapid product launches,” publication and upgrades to the existing Baseline System Specification and Rezence certification program are expected by the end of the year, A4WP said. Dell, which showed a prototype laptop behind closed doors at a private A4WP meeting room at CES, officially joined A4WP in February (CED Feb. 24 p) in an announcement that coincided with A4WP’s introduction of its higher power “initiative.” The A4WP can’t comment on product availability, but it expects member companies to make announcements for products incorporating Rezence technology “in the near term,” an A4WP spokesman told Consumer Electronics Daily.

The A4WP spokesman said the 50-watt charging system will work with any laptop using a Rezence wireless power receiver, and it’s “up to the specific OEM to design the receiver into their device.” In addition to laptops, the 50-watt charging standard can apply to other electronics that require up to 50 watts of power to charge, or to power, including home appliances and power tools, he said. “If the device can use a battery, even if it is over 50 watts, then A4WP may be able to offer a solution for that device,” the spokesman said.

In addition, A4WP said Fujitsu, Hon Hoi (Foxconn), Lenovo, Logitech and Panasonic have joined the alliance, which now has more than 100 member companies. Having a universal wireless charging solution “that’s flexible and scalable is important as consumers buy more devices that require charging,” said Marcel Stolk, A4WP senior vice president, in a prepared statement. Logitech products that are likely to take advantage of Rezence charging include computer and mobile accessories, gaming and music products, he said.

Peter Hortensius, Lenovo’s chief technology officer, said in a prepared statement that in Lenovo’s evaluation of the different wireless charging technologies, the company determined that the A4WP system, operating at 6.78 MHz, best meets customers’ needs “because it delivers the power and convenience necessary to easily charge all your devices.”

A4WP claims that wireless charging technologies operating at frequencies lower than 6.78 MHz are subject to technical limitations that make the extension to higher power charging difficult to implement in a manner that consumers will accept. A4WP’s claim appeared to be targeting the Wireless Power Consortium’s Qi standard, whose charging capacity currently maxes out at 15 watts, A4WP said. Questions to WPC weren’t immediately answered, but the organization has said in the past that it, too, is on an upgrade path to higher wattage charging capability.

The third wireless charging standards group, Power Matters Alliance (PMA), also has higher power charging in its sights, said President Ron Resnick. “All the powers to be are working to get higher power” for wireless charging,” Resnick told us, with PMA on track to have 15-20-watt power cycles by the end of Q4 and 50-watt charging some time after that. “It’s pretty much a logical extension of all the work done by any of the standards orgs to be able to handle support for computers, Ultrabooks, notebooks and tablets,” he said. To get to the higher charging levels, coils and chips going into charging devices have to be able to transfer more watts, Resnick said, and it takes “a little more capability to do this in an efficient way.”

Resnick noted the memo of understanding signed between A4WP and PMA earlier this year (CED Feb 12, p1) in which A4WP has agreed to adopt PMA’s inductive charging spec as a reference, and PMA has in turn adopted A4WP’s resonance spec. “It boils down to use cases,” Resnick said. “Where you need to suit the use case, it’s up to the customer to decide whether they want resonant or inductive technology,” he said.

PMA has been behind a push to install inductive charging stations in public venues including Starbucks, but the PMA solution requires precise contact between the charging elements and contacts on a cellphone case. Rezence products promise to free the user from physical connectivity, enabling people to charge multiple devices simultaneously in the vertical plane as well as on a charging mat. A transmitter could be placed underneath a counter, for instance.

Resnick said PMA made its protocols “completely open” so PMA “is not partial to any industry org” with a goal of having one common network versus three separate wireless charging efforts. He called PMA’s relationship with A4WP “very synergistic” and predicted a rise in multi-mode receivers that will be able charge devices with both technologies. “We think it makes sense for members to consider dual-mode,” Resnick said, saying supplemental costs of doing so would be “negligible” for a manufacturer to make a device capable of being charged using resonance or induction. A device with a resonant and inductive solution “can use the same coil,” he said.

A4WP members including Broadcom, iCirround, Intel, MediaTek and Powerwow are demonstrating different types of Rezence-based products at Computex this week, A4WP said.