Phone battery anxiety is a problem we've all faced at some point, staring at that 5 percent warning wondering if it will survive the trip home. Power banks can be a lifesaver, but it's a pain to carry around what basically amounts to a second phone hanging off the bottom. Bezalel has now unveiled a power bank that sticks to the back of your phone and charges it up wirelessly.

Named Prelude, Bezalel's new wireless battery pack sports a capacity of 5,000 mAh and can blast power out at a speedy 15 W. Designed to be as unintrusive as possible, it measures just 4.5 x 2.7 x 0.67 in (11.4 x 6.9 x 1.7 cm) and weighs 5.3 oz (150 g). It's said to work with most phones that support wireless charging, including iPhones newer than the 8, Samsung Galaxy S6 and up, as well as phones from LG, Sony, and BlackBerry.

But its main selling point is that it can stick to the back of a phone, so you can charge up on the go without plugging anything in. Other similar systems do so magnetically, but that often involves sticking a magnetic patch on the back of the phone. The Prelude, on the other hand, uses tiny suction cups, which apparently provide just as strong an attachment without damaging the phone itself.

Although it's relatively small as far as power banks go, the Prelude does look like it adds a bit of bulk to a phone. That said, it seems like a decent middle-ground between a wired power bank and a battery pack case that beefs up a phone even more.

The Prelude wireless charger has a 5,000-mAh battery that can output at 15 W, and works with recent iPhones, Samsung Galaxies and other phones from LG, Sony and BlackBerry Bezalel

The Prelude also looks more useful than a regular stay-at-home wireless charger. In its current state, we're not so sure wireless charging for phones is that useful a technology. Sure, it's fine when you're leaving your phone on the pad to charge overnight, but you can't really use the phone while it's charging. These stick-on wireless power banks seem like they could go a long way towards fixing that – at least until room-wide wireless charging comes along.

The Prelude is currently seeking funding on Kickstarter, where it's already raised more than twice it's US$20,000 target with 22 days remaining. Super early bird pledges start at $45 for the power bank, while you can add desktop charging pads and magnetic iPhone cases for higher amounts. If all goes to plan, the charger is expected to start shipping in December.

Check out the campaign video below.

Source: Kickstarter