Wireless Power Consortium Achieves Key Technology Milestones

February 11, 2015 by Jeff Shepard

The Wireless Power Consortium (WPC) today made two draft specifications available to its members that extend the capabilities of the Qi wireless power standard. The first extension of the Qi specification, called "Volume II: Medium Power," enables fast charging of smartphones with up to 15 Watts delivered into the battery.

"An increasing number of smartphones require higher power levels and support fast charging at more than 5 Watts," said Matt Ronning, chairman of the WPC's Medium Power Work Group and Director of Engineering at Sony. "The Medium Power extension of the Qi specification increases the transferred power to 15 Watts and lays the ground work for a stepwise increase to higher power levels for smartphones, tablets and notebook computers."

The second extension of the Qi specification, called "Volume III: Shared Mode," enables multi-device charging with a single inverter, a resonant technology that reduces the cost of manufacturing multi-device chargers while providing large freedom of spatial positioning.

"Relentlessly driving down the cost of wireless chargers is necessary for mass adoption of wireless power," said Tony Francesca, chairman of the WPC's Resonance Task Force and VP of Business Development, Consumer Technologies at PowerbyProxi. "The 'Shared Mode' extension of the Qi specification makes wireless chargers that power multiple smartphones and tablets simultaneously much more affordable while delivering a better user experience with improved spatial freedom in horizontal and vertical positioning."

The availability of these draft specifications makes it possible for WPC members to begin developing products and components. The feedback from the product developers will be used to finalize these extensions and release them publicly as part of the Qi Wireless Power Specification.

Extensions to the Qi specifications are always compatible with existing Qi chargers and Qi devices. The WPC's standards development process makes it easy to add new features, such as increasing the X, Y and Z transmission range, transmitting higher power, and enhancing the communications capability of wireless chargers while making sure that new Qi products work seamlessly with existing Qi products.

"These extensions provide WPC members and their customers with a seamless combination of inductive and resonant technologies," said Menno Treffers, WPC's Chairman. "Customers can choose between inductive and resonant Qi chargers and be sure that the chargers work seamlessly with all Qi devices."