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How Does Wireless Charging Work?

From sleek-looking stands and barely-there mats, to chargers you can take along for the ride, we’ll take a deep dive into wireless charging, plus our top picks and future trends.
A wireless charger on a nightstand, charging a smartphone and smartwatch.

Gone are the days of messy wires and the need to actually plug your charger into a device. The advent of wireless charging has allowed us to finally cut the cord, while staying comfortably powered up and connected. But how does it all work? Are some products better than others? We’ll take a closer look into the technology behind it, our favorite products, and a glimpse into the future of wireless charging.

How does wireless charging work?

Plugging a device into a charger means that the device is relying on conductive charging to move electricity from the power source to the device. Wireless charging, also known as inductive charging, is a method of charging electronic devices without the need for a physical connection between the device and the charger. Instead, the charging happens via electromagnetic fields.

Wireless charging usually requires two components: a charging pad or mat and the device in need of a charger. To conduct electricity, both the electric device and the charging pad contains a coil of wire. The connection between the charging pad and the power source (usually a wall outlet) generates an electromagnetic field. This electromagnetic field induces an electrical current inside the device, and that current charges the battery.

In order to induce the current, the charging pad and the device must be close to each other. The strength of the electromagnetic field depends on the distance between coils. The closer the coils, the faster the charge. There is one big drawback to wireless charging: It’s generally not as fast as wiring your device directly to the power source.

Advantages of wireless charging

While wireless may be a little slower, the advantages are unmistakable. Besides, magnetic fast-charging technology (which we’ll cover later) is changing that. But here are some of the other perks:

  • It’s convenient. Cords can be messy and easy to misplace, as anyone who has ever fumbled in the tiny space between the nightstand and the wall to find an elusive charging cord can attest. Wireless chargers, which consist of a simple, sleek pad or stand, stay put and make it much easier to, say, place a laptop on top and continue your work.
  • It’s versatile. Wired charging means constantly toting a slew of different bespoke chargers around to ensure each device can connect to a power source. Wireless chargers are generally one-size-fits all, so you can charge multiple devices on the same charging pad. One caveat: A couple of popular devices, like the Apple watch, don’t support the Qi standard, which can be frustrating. We’ll take a closer look at that below.
Phone sitting on a wireless charger with a larger charging graphic on the phone

Different wireless charging technology

Many of the devices we use on a day-to-day basis support wireless charging—smartphones, smartwatches, earbuds, etc. But, as noted above, devices can use two different types of wireless charging technology (or standards) depending on type and brand: Qi and Powermat. While Qi is the most commonly used wireless charging standard, Powermat is used in public charging stations and is commonly used for things like medical equipment. Here’s a guide to the different types of wireless charging and the devices each type supports.

  • Qi wireless charging. Pronounced “Chee”, it is the most common wireless charging standard. With the notable exception of the Apple Watch, it supports most modern smartphones and accessories. Qi wireless charging works by using a charging pad or mat that generates an electromagnetic field, which induces a current in the coil inside the device that needs to be charged. The Qi standard specifies a frequency range of 110-205kHz and a maximum charging distance of 4cm.

One of the best things about the Qi standard is the fact that it can be used to charge both wired and wirelessly, so if you need the faster charge of the wired connection, you won’t have to go searching for another charger. Additionally, there are different wattages Qi charging--5W, 7.5W, 10W, and 15W. A higher wattage means faster charging speeds, though charging speed also depends on the device being charged and its battery capacity.

  • PMA (Powermat) wireless charging. Powermat is another charging standard that launched to quite a bit of fanfare, with brands like Starbucks and McDonalds adopting Powermat at their public charging stations. Powermat also uses inductive charging to charge devices wirelessly, and the technology was later acquired by AirFuel alliance (more on that below).

Basically, PMA works similarly to the Qi standard, but specifies a different frequency range of 277-357kHz and a maximum charging distance of 5cm. However, one problem with PMA was the fact that it uses a different charging protocol than Qi, meaning that devices supporting PMA weren’t compatible with Qi charging pads, and vice versa. Since Qi became the more widely adopted standard, PMA began to disappear as Qi won the wireless charging wars. However, the company has since shifted its focus to industrial efforts.

  • AirFuel wireless charging. In 2015, the two main wireless charging standards, Qi and PMA, merged into a single standard called the AirFuel Alliance. And in 2017, Apple announced that its devices would use Qi for iPhone wireless technology, meaning the battle was pretty much settled in Qi’s favor. The good news is that many wireless charging pads now support both Qi and PMA in order to support backwards compatibility. The alliance makes it much easier for consumers just looking to charge their devices to stay out of the wireless wars.
  • Magnetic fast charging. Wireless magnetic fast charging works in exactly the same way inductive charging works: by transmitting electromagnetic fields wirelessly between coils. It simply aims to solve the speed issues endemic to charging wirelessly versus connected. Wireless fast charging uses a higher charging voltage and/or amperage to increase charging speed. However, not all devices support wireless fast charging, which is generally limited to newer devices. And not all charging pads are capable of wireless fast charging. These pads may also use different standards, such as Quick Charge, USB Power Delivery, or proprietary technologies.

To identify a charging pad that supports wireless fast charging, check the wattage rating. The numbers 10W, 15W, or 20W indicate the maximum power output of the charging pad, and these outputs are considered wireless fast charging range.

Wireless charging accessories and how to use them

Let’s take a closer look at wireless pads and other types of wireless charging devices and how to use them.

  • Wireless pad. A wireless charging pad is a flat surface that charges your device wirelessly. It is typically designed to be compact and portable, making it convenient to use at home, in the office, or while traveling. They must, however, be connected to a power source like a wall outlet. Once plugged in, simply place your device on top of the pad and wait until the charging indicator appears.
  • Wireless stand. A wireless charging stand functions just like a pad, but holds a device at an angle while charging it wirelessly. This allows hands-free use while charging, making stands ideal for video calls, watching videos, or other activities that require the device to be propped-up. Wireless charging stands may offer different charging speeds and may support different wireless charging standards.
  • Wireless car mount. This is basically just a wireless charging stand that is designed for your vehicle, so it stays put. Just plug it into your vehicle’s power outlet, attach it to the dash or windshield, and it secures your phone as it charges.
  • Power bank/juice pack. Not near an outlet? That’s where a power bank or “juice pack” will come in handy. It is an excellent wireless source of power when there are no plugs in sight, making it easy to charge your device on-the-go.
  • Power station. You’ll find these in public spaces such as airports and coffee shops, where multiple people may need to charge their devices at the same time. A wireless charging power station includes multiple charging pads or coils in order to power multiple devices at a time, along with USB ports and other connectors that allow devices to charge more quickly.

Top wireless charging devices

Whether you’re looking for wireless charging at home or on-the-go and want the fastest charge available, there are plenty of options to keep you powered up without the clutter of cables. Here are some of our favorites:

Best Stand: Mophie 15W Wireless Stand

Sometimes you need a battery boost but don’t want to interrupt the action on your device. This handy stand keeps your device upright while providing 15w of power.

  • Pros: Can continue to use device while charging.
  • Cons: Pricier than more basic pads and other stands.

Best Windshield Mount: iOttie Wireless Dash and Windshield Mount

Keep your focus in the car without worrying about charging with a 10w windshield mount that supports save driving and can keep your device powered even while you’re using navigation or music streaming apps.

  • Pros: Great for safely using navigation while driving.
  • Cons: Only works for smartphones.

Best power bank: Mophie Universal Battery Powerstation Wireless P XL 10K

Get a full charge without an outlet! Just place your Qi-enabled smartphone on the charging surface to charge wirelessly with just the push of a button. For an even faster, wired charge to your devices, use the superfast 18W USB-C PD or USB-A port, so you never have to worry about running out of power.

  • Pros: Can charge devices without an outlet
  • Cons: Only charges one device wirelessly at a time.

Best Budget: GoTo™ 10W Wireless Pad

This sleek device is a great charging pad for those who want to ditch the cables. At just $29.99 it’s less expensive than other wireless charging devices, though it packs a little less power.

  • Pros: Affordable
  • Cons: Less power than other device

Future of wireless charging

As we continue to adopt a wide range of devices into our everyday lives, from phones, to tablets, to watches, and more—the demand for faster, more effective wireless charging has only grown. That means advances like faster charging speeds are likely on the horizon, along with developments like longer-range (contactless) charging. In addition, more and more smart devices will likely come standard with wireless charging capabilities.

Until then, adopting a wireless charging pad, stand, mount, or power bank could simplify your life and cut down on clutter as you move one step closer to cutting the cord for good!

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