Starbucks first implemented wireless charging back in 2015, but not all wireless charging methods were created equal. Powermat installed thousands of charging pads in Starbucks stores that use the Power Matters Alliance (PMA) standard. Now with the majority of phones supporting Qi wireless charging backed by the Wireless Power Consortium, an upgrade is needed.
Fortunately for Starbucks and its customers, a full replacement of hardware is not needed. Wireless charging works by creating an electric field using a coil of wire and then a second coil of wire receives the energy and converts it from a field back to usable electricity to charge a battery. The standards of wireless charging regulate how this process is performed and at what power levels. As a result, firmware updates for the existing Powermat systems in place can be issued to support Qi, or almost any other wireless charging standard that comes along in the future.
The commercial Powermat units that Starbucks uses will deliver 7.5W of power to all three new iPhone variants. This is still significantly slower than using a wired solution which can provide an estimated 18W of power over a USB-C to lightning cable.
There is currently no official schedule for implementation of Qi at Starbucks locations, but it is expected that firmware updates will be rolled out as soon as possible in an attempt to beat the launch of the iPhone 8/8+ and iPhone X.
https://www.techspot.com/news/71001-starbucks-implementing-qi-wireless-charging.html
