Simplified: How does wireless charging work?

With each successive generation of smartphones comes more power, more pixels, and more everything. Year after year we're treated to what sometimes feels like a preset 'upgrade' curve, where the processors, cameras, screens and just about everything else gets a bit better with each new model. But wholly new, exciting features emerge every now and then, mostly on the software side, but sometimes we even get something kind of exciting in terms of hardware, too. One such trend-setter is inductive charging, most commonly referred to as wireless charging, and today is going to be all about this new tech that has proved intriguing, tenacious and forward-looking -- or the Holy Grail of qualities that every up and comer in this industry seems to exhibit at a particular point.

So what is this tech wizardry that charges your smartphone's battery as if from thin air? Actually, it's nothing really fancy, and by saying that we're in no way trying to detract from the achievement that it is. That said, it's worth noting that many credit the bizarre and eccentric scientist from Serbian descent, Nikola Tesla, with laying the groundwork for wireless charging all the way back at the turn of the 20th century. Tesla actually filed a patent that described a device that he believed could transmit electricity from one conductor to another with no wiring whatsoever, and though his work never actually bore practical fruits, his idea evidently stuck. Fast-forward to today, and we have a number of 'alliances' rallying up behind different wireless charging standards, the most popular of which is the Qi standard. Despite the hardware incompatibility between those, they all rely on what is basically the same thing: inductive charging using an electromagnetic field to transfer electrical power between a 'charging station' (a pad, if you will) and a compatible smartphone (or an accessory, like a case). More specifically, once the 'station' is connected to the grid, a little coil within it (the transmitter) passes on an alternating current onto a coil in your smartphone (a receiver), generating a magnetic field. This induces voltage into the receiver coil, which, in turn, charges up your phone's battery. This is what is called 'inductive coupling'.

Unfortunately, there are some limitations of note with the technology, at least at this time. We mentioned the existence of several incompatible standards, of course, but you need to also consider a few other things. For starters, the 'wireless' part is not technically true, as the charging pad still needs to be connected to the grid with a wire. Moreover, the argument over whether wireless charging can be as efficient (and fast) as wired charging does not seem to be completely settled just yet, though the folks behind the Qi standard seem to think that, under what are likely advantageous circumstances, wireless charging could be just as fast and efficient.

On the positive side, the Qi team claims that it has developed a system that will consume just 0.0001 Watts in standby (when nothing is being charged, but its being plugged to the grid), while the typical wall charger is said to consume about as much power when in standby, as when in use. Apart from the 'green' appeal of the tech, wireless charging is inherently compelling for those of us lucky enough to own a smartphone, since battery life is often less than satisfying. More out-of-the-box (read: radical) ideas picture a world where our entire desks, even entire building floors, have millions of those inductive coils transmitting energy throughout the entire surface, allowing you to basically charge your device wherever it is. If the technology does get cheap enough, it's not entirely out of the realm of possibility that a time might come, when our devices will be continuously charged throughout the day, pretty much wherever we are.



1. _Bone_

Posts: 2155; Member since: Oct 29, 2012

I'm hoping for a major global breakthrough not cause I charge my Nexus 4 wirelessly (I don't plan to buy such a charger), but cause if pads make into caf├ęs restaurants and such, it'll be awesome to give your phone a 20% charge when you're stopping by at such a place.

2. Chris.P

Posts: 567; Member since: Jun 27, 2013

Starbucks has actually been doing exactly that, though I don't believe pads have made it in that many locations just yet. :)

3. apple4never

Posts: 1064; Member since: May 08, 2013

i heard its possible to use wireless charging via nfc. is that in fact possible?

12. nak1017

Posts: 328; Member since: Jan 08, 2010

No, different circuit and coil design

4. CaptYolo

Posts: 25; Member since: Jan 30, 2014

If i cant move my phone easily while charging it ''wirelessly'' whats the point??

6. pwnarena

Posts: 1129; Member since: Feb 15, 2013

there's still the advantage of not needing specific wires and plugs to charge. that means restaurants or cafes can have pillows or charging plates you can use while having a meal or sipping some coffee. of course in most cases wired charging is still better.

11. av911 unregistered

For my instance, if my USB port is being used and I'm low on battery, I can charge wirelessly. (Doing this in my car).

16. apple4never

Posts: 1064; Member since: May 08, 2013

your also not supposed to use it while it charges

19. vincelongman

Posts: 5755; Member since: Feb 10, 2013

Depends on the wireless charger. If you have a external battery with wireless charging then you can move while charging and using your phone, but then you have to hold two things. (I mean something like the Nokia DC-50 or Mugen Mugenizer N11)

5. marbovo

Posts: 658; Member since: May 16, 2013


7. Slammer

Posts: 1515; Member since: Jun 03, 2010

I've written posts on this before. Wireless charging is not a preferred way to charge a battery. Because of the incompatibilities of materials used to create induction, heat is created during charges. The greatest enemy of batteries, is heat. We need to remember this as most insurance companies do not recognize batteries as a covered component. Everyone is trying to make bandaid fixes for charging devices whether it be larger batteries, wireless charging or portable battery packs. What the industry needs is the battery technology to move ahead as swiftly as the devices they power. Unfortunately, the manufacturers make profits on consistant sales. Why would they want to make them better? John B.

13. IliyaBeshkov

Posts: 261; Member since: Jul 09, 2012

Nanowire technology is the answer my friend, but it's not 100% ready for mass production. :)

8. IliyaBeshkov

Posts: 261; Member since: Jul 09, 2012

I'm more looking forward to resonant wireless charging, because it's more advanced..

9. Lboogey6

Posts: 281; Member since: Jan 31, 2012

Honestly it's a pointless tech to delve into and waste time, majority of people are on their phone texting, social media, and what not you've picked it up no more charging

14. 14545

Posts: 1835; Member since: Nov 22, 2011

Pointless to whom? You maybe, but I myself find wireless charging at night very convenient. No fumbling around with wires in the dark, just drop and charge. Wires are great in some instances, but in many they suck, and are just a nuisance.

10. Amir1 unregistered

what about the radiation coming from the wireless charging? why not mention that?

15. kozza3

Posts: 778; Member since: Oct 17, 2012

A lot of negative reactions here, I personally use wireless charging with my Nexus 5 and love it.

17. GoBears

Posts: 456; Member since: Apr 27, 2012

Same here bro. I use wireless charging on my S4 and my Lumia 928. Super convenient and zero wear and tear on the port. Matter of fact, I won't get a phone that doesn't support or have the ability to add wireless charging.

18. TBomb

Posts: 1668; Member since: Dec 28, 2012

a cool idea would make it kinda like a self-winding watch where movement in your wrist/arm wind it up... put that technology into your pocket

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