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    The Evolution of Wireless Charging Standards and Their Limitations

    • 4 min read

    The Evolution of Wireless Charging Standards and Their Limitations



    The emergence of wireless charging technologies took a lot of people by surprise, most of whom had almost no idea of how insanely practical this type of charging can actually be. Seen as a fad at first, wireless charging has reached impressive standards in just a few years and it shows no signs of stopping any time soon.

    The journey from where it was to where it is wasn’t a short one, nor was it easy given how reliant people are on traditional chargers. If anything, some believed that once the novelty wears off, people would eventually go back to standard chargers. This hasn’t happened as some of you might have already noticed, and the technology continues to grow at an amazing pace.

    Part of the reason why wireless chargers were able to grip the public’s attention so quickly was the form factor. Compact and easy to install,you can set up a no show wireless charger almost anywhere without making any major changes to your home or office setup; nor are you required to make any alterations to your furniture.

    Another important aspect is the multifunctional, accommodating nature of wireless chargers. Built for versatility, many if not most wireless chargers can accommodate a variety of Qi-ready devices. That said, know that this wasn’t always the case and that it took a while for manufacturers to settle on a set of international standards.

    Wireless Charging Standards

    We spoke about the arduous journey that wireless chargers took to reach the current standards. One of the problems was that there wasn’t a single type of wireless charging straight from the get-go. Instead, there were (and still are) three different wireless charging standards, each employing a different type of transmission.

    •        Qi charging –This is by far the most easily recognizable and widespread wireless charging standard out there. It is so widespread, in fact, that 70-80% of all new smartphones that incorporate wireless charging capabilities use it. This standard was created by the Wireless Power Consortium (WPC) and it supports wireless power transfer of up to 10-20 W or more depending on certain parameters.
    •        PMA charging –Established by the Power Matters Alliance (PMA), this type of charging operates on a frequency range of 100-200 kHz and delivers a 5 W charge over short distances. Although similar to the Qi standard in many ways, they employ different communication methods between the wireless power receiver and the transmitter.
    •        Airfuel –This is the latest in wireless charging standards and the most confusing of them all. Even though it doesn’t present any technical limitations per se, it uses a slightly different principle called “MR” which refers to magnetic resonance. At this point in time, Airfuel delivers about 3.5 to 6.5 W, but the technology showcases a big potential for improvement going forward.

    A fair bit of history

    When wireless charging started gaining traction close to two decades ago, the jury was still out on the ‘proper way of building inductive charging stations. In a relatively short amount of time, it became rather clear that Qi and PMA showcase the highest potential for maintenance and improvement.

    This led to manufacturers adopting them both for first-generation smartphones and tables with inductive charging capabilities. Among the two, Qi charging appeared to gain the most traction, mostly because of how simplistic the design was. In fact,your average no show wireless charger is likely to be a Qi charger on account of how small and compact these chargers usually are.

    Not to say that PMA doesn’t have its own strengths and practical applications, although the methods PMA uses for communicating between receivers and transmitters are a bit prone to malfunctions. Seeing how the goal was to create a reliable and easy-to-maintain interoperational standard, it quickly became clear that Qi was the way to go.

    We can’t talk about Qi (pronounced ‘chee’) charging without referring to its Chinese background, in which Qi basically means ‘natural energy’, ‘life force’, or ‘energy flow’ depending on the context. This provided marketing teams with the perfect opportunity to come up with creative and appealing strategies to popularize the technology worldwide.

    Soon enough, the Qi logo found itself on a wide variety of chargers and smart devices, signifying their Qi-ready capabilities. So when taking a look at what the market has to offer, you will surely see many wireless chargers that operate a Qi standard, which means that these devices incorporate a Qi receiver chip with multi-standard interoperability support.

    Future challenges and prospects

    It’s always been the case that with the advent of new technologies, existing technologies and systems have no choice but to keep up. This is precisely what’s going to happen with wireless charging as we are already seeing major improvements made to Qi chargers by major manufacturers through their proprietary chargers.

    It appears that both speed and reliability need to be improved going forward along with a much longer range. If certain reports are to be believed, we could assume thatyour average no show wireless charger will soon be able to charge smart devices from distances of up to half a meter or more.

    The main problem here is that no matter how much engineers increase the Watt per hour rates, the frequency range is still prone to interference. As such, even a powerful Qi charger with a 40 W delivery could theoretically lose half its charge if there are other devices in the room that interfere with the inductive process.

    One such device is your average wireless router. Not many people know this, for instance, but some chargers operate on similar frequencies to Wi-fi routers, and the stronger they get the more likely it is that they will interfere with one another. For example, a powerful Wi-fi router operates a 2.4 – 5 GHz frequency, which is more or less what high-end wireless chargers use.

    All things considered, these issues will have to be ironed out over time if there’s any chance of getting one day to the point where you could recharge your smart devices from across the room. At the moment, even good ‘wireless’ chargers require that your phone either make contact with the charging pad or at least be positioned a few millimeters away for good measure.