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Most of us who lug portable devices around with us are used to wrestling with a tangle of cables. Wireless charging pads can take at least one cable out of the mix: You place your phone on the pad’s surface, and charging occurs through a technology called inductive coupling.

This technology isn't brand new. But increasingly, new phones have built-in wireless charging capability, so there's no need to purchase a case, sleeve, or back (which are sold separately) to charge. But many current phones still need charging cases—including iPhones.

What we tested
The two main wireless-charging formats found in products today are Powermat by Duracell and Qi, pronounced "chee." (There is also a third wireless-charging standard from the Alliance for Wireless Power or A4WP that has backing from Samsung and Qualcomm.)

Of the four charging pads we tested, one is a Duracell Powermat and charges up to three iPhones. Duracell also makes Powermats that charge one or two phones and models that charge the Samsung Galaxy S3 phone, but we didn't test those versions.

The other three pads use Qi, which is incompatible with iPhones but can charge other types of phones. Any phone without built-in Qi compatibility will require a wireless case or back. The Qi pads are the Energizer IC2B, Panasonic QE-TM101-K ChargePad, and LG Nexus 4 Wireless Charging Orb WCP-400.

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How we tested
We first measured how long phones took to charge using an AC adapter and connecting cable, and then how long they took to charge using the pads.

We also checked the pads for water resistance: Each was sprayed with the same amount of water to simulate use on a kitchen counter, placed in a normal usage position with the pad’s AC cord connected to a wall outlet (but no phones on the pads). Any impairment to the functionality of the pad would be considered a failure—and a possible safety issue.

What we found
Of the tested pads, the Duracell Powermat was the faster charger overall. The average charging times using AC adapters for Powermat- and Qi-compatible phones are comparable: 2 hours 15 minutes and 2 hours 18 minutes, respectively. But while wireless charge time for Powermat phones was again 2 hours 15 minutes, the Qi's wireless method took quite a bit longer than AC charging: 3 hours 21 minutes.

Some pads can charge more than one phone at a time, so we tried that out too. When we charged two phones on the Energizer pad, it took 30 minutes longer than charging two phones on the Powermat. The Powermat is the only one that can charge three phones wirelessly; charging three phones on that pad took just 15 minutes longer than charging two.

As for water resistance, all four pads passed our water safety test with no problems or damage.

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Our take
Wireless charging pads can be handy devices and save you a good bit of plugging in and unplugging—just don't misplace your cables, because you'll need them when you're traveling without the charging pad. Also, the pads are really easiest to use with newer phones that have wireless-charging technology built in, so you don't need to purchase separate charging cases for them.

For iPhone households, we recommend the Duracell Powermat, because it has the fastest charging time performance of all pads tested and is able to charge up to three iPhones at a time. The downside, of course, is that it charges only iPhones.

Of the three Qi-compatible pads we tested, we recommend the Energizer Inductive charger, because it has the fastest charging time. It can charge up to three devices at a time with two on the pad wirelessly and one via a cable connected to the USB port on the back that can charge a non-Qi-compatible phone such as an iPhone. It's compact, lightweight, and relatively easy to use.

Here are specific results for each pad we tested.

Highs
This pad is compact, lightweight, and relatively easy to use. The Powermat’s wireless charge times are just as fast as its AC adapter charge times, and it can charge up to three devices at a time.

The Powermat has a few ways of letting you know that your device is in the right position to charge. When you place a device on a Powermat, you feel a slight magnetic attraction when the device gets close to a “power access point.” The pull guides the device into the perfect position for optimal charging.

The Powermat also plays audible indicators when the phone is properly positioned and charging begins, and when the device is removed from the power-access point. And in case that’s not enough feedback, each power access point has a light indicator that illuminates when the device is properly positioned and charging begins. The light turns off when the device is fully charged or removed from the power access point.

Lows
The Powermat we tested works only with iPhones, and a wireless-charging case, which is sold separately, is needed to charge the phone. The case for the iPhone 5 ($50) is heavy, bulky, and ruins the aesthetic appearance of the phone, so you'll probably want to remove it when going mobile; the iPhone 4/4S case ($26) is nicer looking, not bulky, and adds little to the weight. And the iPhone must be placed precisely on the power access point to charge properly.

Highs
The Energizer pad can charge up to three phones at a time, two wirelessly on the pad and one wired via the rear USB port, using a cable; the latter can be any kind of phone. This versatile pad can charge many Qi-compatible phones across many brands. And it’s compact, lightweight, and relatively easy to use.

Lows
Any phone that doesn’t have Qi compatibility built in requires a wireless-charging case, which is sold separately. If the phone isn’t placed squarely on the access point, it can stop charging. And wireless charge times are around an hour longer than charges using the AC adapter’s wired connection.

Highs
This pad is very compact, taking up very little space.

Lows
The Nexus 4 pad can charge only one phone at a time. And because it has a very restricted access point, it is easy to lose coupling and end charging if you touch the phone while it’s charging; it must be placed very precisely. Wireless charging takes around an hour longer than charging with the supplied AC adapter.

Highs
You can place the phone anywhere on the pad, and an automatic motorized moving coil will move to locate and inductively couple to charge the phone. A circle of blue LEDs shows you where the coil is moving.

You can place two phones on the pad: After one is fully charged, the pad finds and charges the second phone. And the pad is compact, lightweight, and very easy to use.

Lows
Wireless charge times take around an hour longer than using the AC adapter’s wired connection, and the pad can charge only one phone at a time. Being a Qi charger, any phone without built-in Qi will require a wireless case to charge. Oh, and the manual and all instructions in the sample we bought were in Japanese.

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