Silicon Valley Starbucks serve up wireless charging but you’ll need a special phone case

After trialing wireless charging stations in Boston, Starbucks(s sbux) is expanding the program to select locations in Silicon Valley. Before you get too excited by the prospect of free device juice with your morning latte, make sure you check which wireless charging standard your phone or tablet uses.
Starbucks is using wireless technology based on the PMA, or Power Matters Alliance, standard. That makes sense when you read this brief bit from the PMA “About Us” page:

“The PMA’s agenda is spearheaded by like-minded leaders of industry and government, including representatives from Procter & Gamble, Google, Starbucks, AT&T, Powermat Technologies and the US Department of Energy.”

Here’s the rub: Most of the recent devices that support wireless charging don’t use the PMA standard. Instead, they support Qi, an older standard. Need some examples of Qi-supported devices? The new Nexus 7 tablet, HTC Droid DNA, Samsung’s Galaxy S 4, Nokia’s(s nok) Lumia 928, and Google’s Nexus 4 smartphone all support Qi, meaning you can’t recharge them wirelessly at participating Starbucks locations.

Apple’s(s aapl) iPhone doesn’t natively support any kind of wireless charging, but Duracell Powermat, a key member of the PMA, does sell cases that add the charging capability. The company also sells a similar add-on for the Galaxy S 3. But when it comes to devices that natively support wireless charging, I can’t think of one that works with the PMA standard yet.
Earlier this year, AT&T said it would be backing the PMA and that devices it sells will use the standard. If that happens, it could help push the PMA standard to the forefront; especially if Starbucks continues to expand the wireless charging service at more locations. On a related note, AT&T’s biggest competitor, Verizon (s vz)(s vod) is a member of the Wireless Power Consortium, which backs the Qi standard.
For now, you can expect Starbucks to make your coffee just the way it works for you, even if your smartphone doesn’t yet work on a Starbucks charging pad.