Starbucks is always looking for ways to bring customers through its doors, and it's found great success in appealing to today's tech-savvy customers with options like free Wi-Fi and app-based payments. Its latest initiative sounds good on paper, but it may leave many customers out of luck.

The coffee chain is rolling out wireless recharging stations to its 8,000+ stores across the United States. A handful of these charging stations have already been tested in Starbucks stores in Boston and San Francisco, but now the technology is going big. The Duracell Powermat will be available to charge smartphones and other handheld gadgets via flat, disc-shaped charging mats that will presumably be situated on (or perhaps under) Starbucks' dining tables. Most stores are expected to receive 10 or more Powermats, which should total out to at least 100,000 nationwide.

"We were pleased with the customer response to the pilot tests," says Adam Brotman, Starbucks' chief digital officer, "and we're now expanding this offering nationally to provide our customers a quality and reliable experience as they use our stores as their respite, their office away from home or as a gathering place with their friends and family."

Duracell's Powermats are built using the Power Matters Alliance or PMA standard for wireless charging. Very few consumer devices that come with built-in wireless technology use the PMA standard; almost all of them use a competing standard called Qi ("chee"). This means that most Starbucks customers who enter their local store and find wireless charging mats will be disappointed to realize that it doesn't work with their phone.

Granted, the number of devices capable of wireless charging out-of-the-box are a small fraction of the total handheld devices owned by consumers nationwide. Most of those were Google Nexus or Nokia Lumia devices. Scuttlebutt suggests that Apple's iPhone 6, expected Fall 2014, will incorporate wireless charging technology, but it's unknown which of the two standards Apple will embrace. (Given Apple's successful cross-promotions with Starbucks in the past, it's not hard to imagine the two titans partnering on this standards issue.)

Customers who want to make their device compatible with Starbucks' wireless charging mats will have to buy a special case that costs $30 or a small "ring" accessory that's more affordable at $10. Starbucks says that other major markets can expect to get Powermats by 2015, with more stores to follow. You can search for Powermat-friendly Starbucks locations here, as well as sign up to be alerted when wireless charging comes to your nearest store.