Wireless Charging Powers Forward for Mobile Devices

Gadgets are increasingly becoming more mobile and wireless, and we're breaking free of cords and wires--or so we wish. Even wireless devices have to be plugged in every so often to recharge their batteries. Wireless charging technology could change that, though, and enable us to live in a truly cord-free world.

What if you could travel with just one charging option for all your digital devices, instead of lugging around a tangle of charging cables? Wouldn't it be nice if you could set down your smartphone on a special charging table or car dashboard to power it up without any cords?

Major growth is coming soon for the wireless charging market, according to market research firm iSuppli. The company predicts a 65-fold increase in the overall market in the next few years, and estimates that more than 230 million electronic devices with wireless charging functionality will ship in 2014.

In this article, I'll discuss the pros and cons of inductive and conductive wireless charging technology, and I'll describe how three wireless charging products worked for me.

Why Wireless Charging?

Plugging your device into an electricity source with a cord is a tedious pain--especially when you consider the diverse array of connector types and power cords involved. Traditional charging relies on electricity conducted directly between a device and a connecting physical wire or through contact with batteries. On the other hand, inductive charging uses magnetic and electromagnetic energy to induce a transfer of power wirelessly. Many electric toothbrushes charge this way.

Most smartphones rely on old-fashioned conductive charging, requiring you to plug in the handset. However, you can charge the Palm Pre by placing it on the HP Touchstone wireless charging base, because inductive charging technology is built into the Pre's case. Both HTC and LG announced smartphones at the 2011 Consumer Electronics Show that include wireless charging capabilities built into their batteries.

Other wireless charging options include the Energizer Qi, the Powermat, and the Duracell MyGrid, all of which enable users to wirelessly charge a variety of gadgets and devices.

It's awesome to be able to charge a mobile gadget without the hassle of untangling cords and plugging it in; you just set the device down on a charging pad and walk away. A single charging system can work with devices from different manufacturers, and in some cases it can even charge multiple devices simultaneously.

The technology still has some kinks to work out, though. For each of your devices, you need some sort of charging sleeve or a connector to a charging module; unlike the Palm Pre, other gadgets don't have inductive charging technology built in.

Another drawback is that you must have access to the charging mat. The convenience of not having to worry about cords is lost when you must ensure that you have both the right proprietary inductive charging sleeve and the appropriate charging mat.

In Video: Wireless Power Charges Ahead

Wireless Charging Standard

Imagine if hotel rooms came standard with universal charging mats. Instead of having to carry the bulky chargers for your laptop, mobile phone, tablet, e-reader, and music player--and being out of luck when you forget one at home--you could simply set your gadgets on the charging mat.

That's the goal, more or less, of the Wireless Power Consortium. The organization--consisting of more than 70 companies--is developing the Open Inductive Charging Standard, more commonly known as Qi. Named for the Chinese word for "life force," the Qi standard enables devices from different vendors to charge interchangeably as long as they are Qi-compliant. Only a handful of Qi-compatible products are available currently, and the standard has existed for just a few months, but so far it's showing impressive momentum.

The key to the long-term success of wireless charging is standardization. As long as charging systems such as the Powermat work only with their own proprietary hardware, the concept will continue to be a niche novelty. But if many vendors agree to standardize devices and to make charging systems interchangeable, as is the case with the Energizer Qi, the possibilities are nearly limitless.

Next page: A look at three wireless charging mats

Hands On With Wireless Chargers

I spent several weeks using three different wireless charging platforms, from Energizer, Powermat, and Duracell. The charging mats and the necessary charging sleeves enabled me to experience a life without wires--almost.

The total cost of any of these three wireless charging products can vary by $25 or more, depending on the number and types of devices you wish to charge as well as on whether you take advantage of components such as rechargeable, portable batteries. In general you can expect a basic setup, including the charging mat and the appropriate charging sleeve for your smartphone, to run just under $100.

Energizer Qi ($90): The Energizer Qi is compliant with the Wireless Power Consortium standard. That's a plus for the Energizer system--assuming that other Qi-enabled devices or charging mats soon become available to take advantage of it. As long as my Energizer Qi mat and my Energizer Qi iPhone 4 sleeve ($35) are all that I can work with, it's really no different from the proprietary Powermat system.

I really like the look and feel of the Energizer Qi iPhone 4 sleeve, which is smooth, solid, and a nice fit on the phone. It does add some heft, though: The sleeve weighs about twice as much as the Powermat's iPhone 4 sleeve, adding just over an ounce to the total weight of the smartphone.

I had two big issues with the Energizer Qi system. First, the charging mat itself is big (it's fairly flat, but it takes up about as much space as a sheet of paper) and not aesthetically pleasing. It isn't the sort of thing I want visible in my home as a permanent fixture. The second, much larger problem is that you have no way to sync the iPhone 4 with iTunes or your PC while it is in the Energizer Qi iPhone 4 sleeve. For other smartphones that can sync wirelessly--which in all fairness the iPhone should be able to do--this obviously would not be an issue.

Powermat 2x Mat with Powercube ($70): The Powermat charging system, on the other hand, has a Micro-USB connector in the bottom of the iPhone 4 charging sleeve. It comes equipped with a USB-to-Micro-USB cord so that you can still connect the iPhone 4 to your PC and sync its data without having to remove the phone from the charging sleeve. Of course, the irony of needing a wire to maintain the functionality of my smartphone while using it with my "wireless" charging system is not lost on me.

The Powermat charging system is much more versatile than the Energizer Qi. Sleeves for a variety of smartphones are available, ranging in price from $20 to $40; the assortment covers iPhones as well as Android and BlackBerry handsets. Plus, you can find charging sleeves for the Nintendo DS and DS Lite, an inductive charging dock for the iPod and iPhone, and a universal charging module for devices that aren't equipped with sleeves. Powermat also offers a portable rechargeable battery that you can charge wirelessly and then carry as an emergency backup for your mobile device.

As with the Energizer system, I have two complaints about the Powermat. The first problem is with the flip-down top of the iPhone 4 sleeve, where the device slides in; it clips on too snugly, and getting the iPhone 4 in and out of the charging sleeve is a pain. The flip-down part seems unnecessary. The other issue is that Powermat's technology is proprietary--although I like the Powermat system more than the Energizer Qi system today, I would rather invest in a standardized platform that doesn't lock me in to one vendor.

Duracell MyGrid Cell Phone Starter Kit ($57): Falling somewhere between the Qi and the Powermat is the Duracell MyGrid charging system. The MyGrid cell phone starter kit comes with a MyGrid power clip and the necessary adapters to connect with a variety of BlackBerry, Motorola, and Nokia handsets. Similar to Powermat, Duracell also offers a rechargeable portable battery capable of providing up to 35 hours of additional power.

Unlike the other two wireless charging systems, the Duracell MyGrid uses conductive, rather than inductive, technology. Power transfers from metal strips on the MyGrid charging mat to metal contacts on the charging sleeve or clip, but the MyGrid mat is engineered so that it's safe to touch and not a shock hazard.

The charging sleeve for the iPhone 4 is a lightweight, flexible rubber case. It's my favorite of the three; like the Energizer Qi sleeve, however, it does not provide any way of syncing the iPhone 4 while the handset is in the case.

Duracell's charging mat is less sleek and attractive than Powermat's system, but it has the advantage of being able to charge up to four devices simultaneously. And it's less picky about where or how devices should rest on it in order for them to connect and charge.

The MyGrid seemed to charge a little faster than the other two products did. Recharge times on the Duracell were more like plugging my iPhone 4 into the wall, while the Powermat and Energizer models were somewhat slower--more like charging the iPhone 4 with a USB cable connected to my PC.

Going Sleeveless

Wireless charging for mobile devices is cool and has potential, but currently it doesn't really make life more efficient or convenient. Instead of having to connect your smartphone to a charging cord, you have to make sure you have the right charging sleeve. Instead of needing the right adapter and connector to juice up your gadget, you require the appropriate charging mat. These are the same drawbacks as with wired charging, but with different items to remember.

For my iPhone 4, in fact, cord-free charging actually adds complexity. Instead of connecting the phone to my PC via USB cable and then charging, syncing, and backing it up simultaneously while I sleep, I now have to charge the phone wirelessly, and then connect it to the PC to sync and backup. That might even require removing the charging sleeve, depending on the wireless charging platform.

"It is about time some sort of standard emerges for charging devices," says Al Hilwa, an analyst for research firm IDC, adding that vendors have had little financial incentive to adapt a shared standard.

However, the Qi standard has major backing--including from Duracell, Energizer, Motorola, Nokia, and Samsung--so the future looks bright.

If Qi gains momentum, then smartphone, tablet, and laptop vendors will simply build Qi-compatible inductive charging functionality into the cases of their devices, eliminating the need for external charging sleeves.

The Wireless Power Consortium envisions incorporating Qi into a wide range of settings, including homes, hotels, airports, convenience stores, and restaurant chains. Imagine if automobile manufacturers built Qi-compatible charging into vehicles.

Wireless charging everywhere could be great--but today it remains a cool, niche novelty.

In Video: Powermat Eliminates Charging Cables

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