Roundup: Wireless charging options for Apple's iPhone

Duracell Powermat

The Duracell Powermat system is the most popular standalone implementation of Powermat's inductive charging technology, which is quickly gaining popularity. Heavily-trafficked places like Chicago's O'Hare airport and New York City's Madison Square Garden have added Powermat support, and General Motors will integrate the technology —  first introduced in Chevrolet's Volt —  into more members of its fleet in 2014.

Duracell's system consists of two parts: the AccessCase iPhone case with an inductive coil that sits just below the device's Lightning port and the Powermat itself, which comes in three sizes to accommodate charging one, two, or three devices at once. The cases, created by famed designer Yves Behar, add approximately 0.5 inches to the height of an iPhone 5 or 5s, though they weigh just 1.05 ounces, and a two-part design allows access to the Lightning port even with the case on.

After ensconcing your iPhone in the AccessCase, Duracell says that their system will charge "at speeds comparable to wired charging." All Powermat-based systems are interoperable with one another, so Duracell's case will also allow you to wirelessly top up your battery if you find yourself waiting for a delayed flight in the departures lounge at Chicago O'Hare or attending a Knicks game.

Duracell's AccessCase is available in black or white for $49.99 and a single-device Powermat is priced at $39.99. Duracell also sells external batteries and battery cases, similar to Mophie's popular Powerstation and Juicepack lines, that work with Powermat.

iQi Mobile

Powermat's main competition for wireless charging ubiquity is the Qi standard, backed by a diverse array of companies from semiconductor giant Qualcomm to mobile device makers like Sony and Nokia. Like Powermat, Qi stations are beginning to crop up at major airports, like New York's John F. Kennedy International, while national coffee chain The Coffee Bean and Tea Leaf is adding Qi charging hotspots in stores. Qi is also the technology used by Google and Samsung for the wireless charging functionality in their flagship handsets.

The iQi Mobile charger is a thin Qi receiver designed to be small enough to slip underneath a soft iPhone or iPod touch case. A flexible ribbon cable runs from the iQi to a Lightning connector, allowing the receiver to remain plugged in when folded behind the device.

At its thickest point —  the Lightning connector —  the iQi is just 1.4 millimeters thick, with the bulk of the receiver coming in at less than 1 millimeter. The iQi's backers say that users who already shroud their device in a soft case will note a barely perceptible difference.

One issue with the iQi is lack of access to the Lightning port once the device is installed —  though we haven't yet been able to test the iQi, unplugging it without removing the receiver from the case appears to be a daunting task that could potentially damage the iQi thanks to the ribbon cable's thin design.

The iQi is a Qi receiver only, meaning that a transceiver — the base station half of an inductive charging duo — must be purchased separately. Like Powermat, Qi devices are interoperable, so any Qi transceiver will work with the iQi.

The iQi team is funding manufacturing through a campaign on crowdfunding site Indiegogo which runs until Dec. 30. An iQi Mobile receiver and case package sits at the $25 reward level, and backers can add a transceiver to the set for $65. Larger packages with additional receivers and transceivers are also available.

Mix-and-match

Because the Wireless Power Consortium, the standards body in charge of certifying Qi devices, has done well in ensuring device interoperability, purchasing receivers and transceivers from different brands is a low-risk proposition for consumers who wish to do so for cost, location, or aesthetic reasons.

Nokia's DT-900 wireless charging plate is a well-reviewed Qi transceiver wrapped in an attractive package that matches the company's Lumia series of devices, though its good looks come at a premium —  the device's $54.99 price tag is much more expensive than competing offerings from the likes of Lerway and

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Qi-enabled cases hover around the $20 mark, with Evotouch and Choetech providing some of the most popular units.

Consumers who prefer the Powermat standard have essentially one choice —  Duracell's products —  for home use. Powermat's status as a commercial technology, as opposed to Qi's standing as an international standard, has restricted the third-party market.