The battery inside your phone is its greatest weakness. It can render even the fanciest little Uber-calling, Snapchat-sending pocket machine a several-hundred-dollar paperweight. That’s mostly because battery technology hasn’t changed that much in a decade , and it’s why the Googles and Apples of the world are investing time and resources into figuring out how to make batteries last longer.

But what if you didn’t need a more powerful battery? What if there were a way to charge your phone, no matter where you were, without having to plug it in? And what if this bountiful energy source were as ubiquitous as, say, Wi-Fi?

uBeam this week announced it has a fully functional prototype that will eventually become a consumer product to do just that. With uBeam, you can pace around a room holding your phone, and the wireless charging system supplies it with power without you ever noticing.

The wireless charging system supplies power to your phone without you ever noticing.

This is accomplished using ultrasound. A charging station converts usable electricity into ultrasound waves, which the system transmits throughout the room. A small receiver is attached to the phone’s case, which catches the ultrasound waves and converts them into battery power, no power cords or energy mat required.

The company was founded by 25-year-old Meredith Perry (one of Fast Company‘s Most Creative People in Business), who developed the technology while she was still a student at the University of Pennsylvania. It’s incredibly promising, too. The company is currently closing a Series A round of financing, and previous backers include Marissa Mayer and Andreessen Horowitz. It does, however, have its limitations: uBeam can’t pass through walls like Wi-Fi can, meaning you’ll need several transmitters sprinkled throughout your household.

Imagine the possibilities, though: Coffee shops that charge your laptops and gadgets as you work, no need to fight over outlets. A stroll through the mall or subway station means your battery life never dips below 90%. Although uBeam didn’t say when the device is coming out, Perry did mention to Engadget that it will be available for both consumers and businesses to purchase. Sometimes the best technology is the kind you can forget about.

[h/t: New York Times]