ho loves wires? No, there is no -philia word for wires, we checked. Unless you’ve got a particular obsession with ductility, it is unlikely that you are a big fan of things connected to each other with physical cords. One of the biggest culprits is charging cables. Almost everyone in the industry has tried their hand at innovating the same MagSafe, Micro-USB and even type-C until the actual solution was finally upon us – wireless charging. Even that is hardly popular right now with few consumer devices actually supporting it. Why is that the case? Is there something wrong with how it has come to be? Let’s find out.
For a long time, people wouldn’t really need to think about wireless charging. Why? Because most of the electronic devices we owned were not intended to be portable. They were firmly rooted in our homes and offices, comfortably plugged into a power supply. Now, almost everything an average person operates in their day to day life comes with a battery-powered alternative. However, carrying around a charging cable for every device (even with popular standards such as Micro-USB and now type-C, device manufacturers don’t play well with each other) can be cumbersome. Hence, the world needs wireless charging right now. But a long time back, we were still trying our best to make wireless charging happen due to sheer curiosity.
If you go looking for the one person who invented wireless electricity or charging, you’ll have a tough job. There are no prizes for guessing who is the most popular name in the lot. After most of the 19th century was spent in establishing the existence and true nature of electromagnetic waves, Nikola Tesla started experimenting with wireless electricity transmission using inductive and capacitive coupling in his experiments. The devices he used to do so were essentially electrical resonant transformer circuits, now popularly known as Tesla coils.
He even improved upon his initial achievements like using a receiving LC circuit tuned to resonance with the transmitter’s LC circuit using a resonant inductive coupling to increase distance. Even after successful public demonstrations over a comparatively limited range, Tesla failed to make his advancements a commercial success – although today quite a few of his ideas power a number of modern devices. That didn’t stop the geek idol from dreaming even bigger.
He envisioned a plan to transmit electricity around the world wirelessly using the ionosphere as a conductor. His grand vision, the ‘World Wireless System’ to transmit power and information was unveiled in 1900, and was followed by the construction of the Wardenclyffe tower in New York as one of many such towers to be built around the world. Eventually, investment dried up in 1904 and the project had to be abandoned.
Fast forward to the very beginning of the 21st century, Samsung was taking a lead in developing wireless charging technology for its consumers by actually setting up a dedicated team to work on it. The same team realised soon enough that for the process they intended to follow (inductive charging) the parts required were either too big, too expensive or both, to be viable for end users. It took almost a decade for that technology to reach approachable standards.
Towards the end of that decade, the Wireless Power Consortium was set up by a bunch of companies to promote the Qi standard (pronounced Chi) – based on the inductive resonant coupling. This standard still wasn’t truly wireless, since, in addition to it requiring a charging base to be wired into a socket, it also required the device to be within 5 mm of the charging base. Although, that limit was overcome soon and the specification was extended to the medium power supply level (up to 120 W). While it is widely believed that in 2011, Samsung became the first company to bring out a wireless charging pad for the Droid Charge (SCH-i510), it was actually the Palm Pre in 2009. Armed with a wireless charging compatible back and an inductive charger dubbed Touchstone, it would be the first commercially available wireless charging solution.
Although LG and Nokia had beaten Samsung to inbuilt wireless charging support with the LG Optimus LTE2 on one side and the Lumia 820 and 920 on another, it wasn’t to stay that way for long. Samsung eventually took the lead with the Galaxy range of devices, with the Galaxy S6 onwards supporting inbuilt wireless charging. Additionally, Samsung also refined the ergonomics of the wireless charging setup by supporting a vertical charging arrangement, something that would significantly improve the usability.
While one part of the tech industry might be busy patting itself on the back for bringing wireless charging via inductive charging, another part has been busy bringing about true wireless charging – something that can power devices across a room, or even farther.
If you’ve been keeping track of CES extensively over the last few years, you might have noticed a company named Energous touting true wireless charging technology for quite a while. Founded in 2013, the company has been demoing WattUp, radio frequency (RF) based charging solution that delivers power via radio bands, similar to a Wi-Fi router. The idea of using radio frequencies for transmitting power isn’t new. In fact, some of the earliest public demonstrations of wireless power transfer using radio waves date as far back as 1964.
What Energous did claim to do was increase the efficiency. While they have claimed that they aim to bring out successful wireless charging solutions the work even at a distance of 15 feet, their current offerings work at a few inches. They have explained that their focus was redirected towards miniaturisation – which they have achieved, with Sticker-like receivers the size of a paper clip. While medium range power transfer is supposed to be released soon, the actual 15-feet long range transfer should release early next year according to the company.
As mentioned earlier, what we refer to as ‘wireless charging’ today isn’t true wireless. That doesn’t mean it is going away anytime soon. Inductive charging provides a level of efficiency and reliability that other solutions, including RF-based ideas, haven’t been able to demonstrate yet. For critical applications such as household appliances or electric vehicles, inductive charging will remain the way to go.
Using radio frequencies for power transfer is gaining traction and is most likely to be realised in home environments. Much like the connected homes of today, technologies like WattUp from Energous are going to make your home a wire-free zone from a power point of view as well – but they’re unlikely to make much difference anywhere else in our day to day lives anytime soon.