When wireless charging systems for smartphones and other gadgets first came on the scene a couple of years ago, they were cool in concept but rather clumsy in practice. The idea was that instead of plugging your phone into a charger, you could simply toss the phone onto a mat from the likes of Powermat or Pure Energy Solutions to charge it.
But in order to get the charge from the mat to the phone, you had to have a receiver on your phone -- and that meant putting on a bulky case or battery door that added significantly to the phone's heft. And if there wasn't a case or battery door available for your particular phone, you had to plug the phone into a universal receiver, which certainly isn't "wireless charging" in my book.
These limitations remain, but Powermat is fighting the bulk problem with a slimmed-down line of receiver cases and doors for half a dozen smartphones, including the iPhone 4, the BlackBerry Bold 9700 and the Android-based HTC Evo 4G.
I tested the new Powermat Wireless Charging System for iPhone 4, which includes a thin new receiver case and a charging pad that's just big enough for a single iPhone.
A less chunky case
Once you've wrestled it out of its packaging, the hard plastic iPhone 4 case slides onto the phone easily and snaps snugly into place, leaving appropriately placed holes for the camera lens, audio in/out jack, power button, mute switch, volume buttons and speakers. (Like other iPhone 4 cases, Powermat's receiver case fixes the phone's antenna problem.) Because the case plugs into and covers the iPhone's dock connector, it has a micro USB port for syncing the phone with a computer (a micro-USB-to-USB cable is included).
The receiver case measures 14mm at its thickest point, only about 2mm thicker than a typical iPhone 4 sleeve case. That's a significant improvement over Powermat's 18mm-thick receiver case for the iPhone 3G/3GS, but of course the iPhone 4 itself is more slender than the iPhone 3G. The earlier case also had an unsightly bulge at the back, while the new case has a flat back.
The new receiver case does, however, add about 4 oz. to the phone's weight and tacks on about 6mm to its height (when you're holding it in portrait orientation). Worse, the case's black plastic has a cheap look and feel to it that ruins the iPhone's high-class aesthetic. That seems like a silly quibble, but part of the appeal of a wireless charging system is that it looks cool; the case should too.
Nevertheless, the system works as advertised, and it helps neaten up your workspace if, like me, you habitually charge your phone by plugging it into one of your computer's USB ports. The iPhone-size 1Xi charging pad takes up minimal desk space and plugs into an AC socket; I found it easy to keep that wire out of sight behind my desk on its way to the power outlet.
Unlike Powermat's other charging mats, which are flat on top and a bit larger than the devices they're meant to charge, the 1Xi pad is fitted exactly to the shape of the iPhone 4 receiver case, with a tall lip at each end. This means you can't just toss your iPhone onto it any which way as you can with other charging mats; it also means that smartphones other than the iPhone 4 won't fit right on the pad. But you can just set the encased iPhone 4 down, properly aligned, to begin charging.
A caveat: It's easy to place the phone the wrong way around on the charging pad -- the top of the phone has to be at the top of the charger (where its power cord connects) or else it won't charge. However, when you place the phone on the pad properly, it makes a distinctive sound to let you know a connection has been made and the device is charging. (A similar sound plays when you pick up the phone.) I quickly got used to listening for the sound to make sure I had placed the phone correctly.
In my tests, charging the phone from the 1Xi pad wasn't appreciably faster or slower than charging from the iPhone's outlet charger or from my computer via USB. When the phone's battery is fully charged, the pad automatically stops sending power to it.
The complete wireless charging system for the iPhone 4 costs $59.99. You can also buy just the iPhone 4 receiver case, which works with any Powermat charger, for $39.99.
To my way of thinking, $60 is a lot to pay just to save yourself the trouble of plugging in your phone. But it is undeniably convenient to just drop the phone onto the pad to charge. If you want to speed up your charging routine ever so slightly -- or you just can't bear the clutter of wires trailing across your desk or tabletop -- Powermat's kit will serve admirably. I just wish the case were more polished-looking.
Truly effortless wireless charging will come only when universal chargers are everywhere and receivers are built right into mobile devices. Until that day, charging mats and receiver cases are the next best thing, and Powermat's slim new iPhone 4 case is a step in the right direction.
Valerie Potter is a features editor at Computerworld.