An illustration of a wireless charger with the Qi logo.
Andrey Suslov/Shutterstock, WPA/Qi

If you’ve taken the time to shop for a wireless charger, then you’ve probably bumped into the term “Qi-Certified.” But what the heck is Qi, and why should you use a Qi-Certified wireless charger?

Qi Is Just a Wireless Charging Standard

Qi (pronounced “chee”) is a standard for wireless energy transmission. It’s a format that’s maintained by the Wireless Power Consortium (WPC), and it aims to standardize wireless charging across all devices in the same way that the USB or Bluetooth standards have standardized data transmission across all devices.

But why does wireless charging need to be standardized?

Well, without a standard like Qi, wireless charging would be a serious pain in the ass. Imagine if every smartphone used its own unique cable instead of Micro-USB, USB-C, or Lightning. Without the Qi standard, that’s the nonsense that you’d have to deal with.

We say “basically” because, technically speaking, it’s possible for unstandardized wireless chargers to work with unstandardized phones. But co-mingling power standards with unsupported devices is both ineffective and dangerous.

The Qi Standard Keeps Things Safe and Easy

Wireless chargers rely on magnetic induction or magnetic resonance to transmit energy (Qi uses both). It’s sort of like the magnetic field that surrounds the Earth. Your phone contains a coil that converts this magnetic energy into electrical energy, which then charges the battery. Simple, right?

A girl freaking out while holding an exploding phone. Clearly, she didn't use a Qi-Certified wireless charger.

That’s why it’s technically possible for unstandardized wireless chargers to work unstandardized receivers in phones. But let’s imagine a world without wireless charging standards. You’d run into three big problems:

  • Overloading Phones: Smartphones have built-in voltage limiters that prevent wired overcharging. But wireless charging relies on a coil, like a coil on an electric stovetop. Without a wireless charging standard, a high powered wireless charger (say, 25 watts) could damage a low-powered wireless phone’s coil (which may have a limited range of 0-5 watts) along with its battery and other internals.
  • Overheating: This is already a common problem for high-voltage (or cheap) wireless chargers. Without proper power management or ventilation, heat will build up and damage your phone. Enough heat can cause a battery to deteriorate, which can also lead to fires.
  • Heat Transfer to Nearby Objects: Without built-in Foreign Object Detection (FOD), a wireless charger may be inclined to push magnetic energy at things that aren’t phones, like pieces of metal or nearby objects. This can cause overheating, fires, or burns.

The Qi wireless charging standard effectively ensures that we’ll never run into these problems. When a phone or charger is Qi-Certified, it’s tested by the Wireless Power Consortium for safety, effectiveness, and compatibility. Qi-Certified devices must operate from 0-30 watts (the Qi standard can go up to 1 kilowatt, but not for phones), pass temperature tests, and comply with Qi FOD standards. They also need to be compatible with all other Qi-Certified devices (phones or chargers), the same way that all Micro-SD cards work with all Micro-SD ports.

RELATED: How Does Wireless Charging Work?

Other Wireless Charging Standards Exist, and They’re Dead

The Powermat (PMA) from 2009. It operates on the PMA charging standard, which has been superseded by Qi.
The 2009 Powermat. It operates on the PMA charging standard, not Qi. Powermat

We’re talking about Qi as if it’s the only standard for wireless charging. That’s because, while there are other wireless charging standards, they aren’t really relevant anymore.

Honestly, we’re okay with that. Different wireless charging standards don’t play nice together, so it’s better (at a consumer level) for all phones and wireless chargers to support a single format. But for the sake of knowledge and tech history, what are some of the other wireless charging standards?

Well, there’s Powermat (PMA), which uses magnetic induction to charge devices. Remember those funky charging mats from 2008 or 2009? Those were PMA wireless chargers. Samsung Galaxy phones (the S8, S9, and S10) still support the PMA standard (alongside Qi), but people complain that the S10 doesn’t work with all PMA chargers.

The other notable wireless charging standard is called AirFuel (formerly Rezence) which relies on magnetic resonance to charge devices. It’s supported by a handful of outdated devices that nobody cares about, including an iPhone 5s case.

Should these alternative wireless charging standards get another shot at life? That’s like asking if it’s okay for another USB standard to come out. It might drive competition a little bit, but it would also make everything more complicated than it needs to be.

The Future of the Qi Standard

Wireless charging is a hot topic right now, and it’s hard to tell where things are going. The technology is still in its early stages, and while charging a phone on a plastic stand is nice and all, wireless charging has a lot of potential for future applications.

Just don’t expect a wirelessly charged car anytime soon.  As of right now, the WPC seems to be laser focused on… kitchen appliances and power tools. Hey, don’t judge, we all have to start somewhere, right?

A phone charging on a Qi-Certified wireless charging pad.
Daniel Jedzura/Shutterstock

The name of the game here is efficiency and convenience. There’s no point in selling a wireless charger if it wastes power, charges significantly slower than wired solutions, or is too inconvenient for regular use. Right now, the Qi standard can support up to 1 kilowatt of power transfer. By focusing on kitchen appliances and power tools, the WPC will hopefully find a way to perfect wireless kilowatt power transfer, while also figuring out how to build integrated wireless chargers (in counter tops, under carpeting, etc.).

Don’t Buy Un-Certified Wireless Chargers

If a wireless charger isn’t Qi-Certified, then you should avoid buying it or using it. Qi-Certified chargers from Anker, CHOETECH, and Yootech are already incredibly cheap, and they come with the guarantee that your phone won’t overheat or become damaged while wirelessly charging.

If you want to buy an older PMA or AirFuel charger (for whatever reason) make sure that your device complies to their charging standards first. Or, you could just drop $12 on a Qi-Certified charger from CHOETECH.

Sources: Wireless Power Consortium, MakeZens, Wikipedia

Profile Photo for Andrew Heinzman Andrew Heinzman
Andrew Heinzman writes for How-To Geek and Review Geek. Like a jack-of-all-trades, he handles the writing and image editing for a mess of tech news articles, daily deals, product reviews, and complicated explainers.
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