What Is Wireless Charging & How Exactly Does It Work? [MakeUseOf Explains]
We live in a wireless world. Except we don’t. Sure, we can send huge amounts of information across the airwaves, but the devices capable of sending and receiving it are tied down to power cords. Batteries allow some freedom but, eventually, we all have to come back around to the familiar face of the power outlet.
What if we didn’t? What if we could charge anywhere, at any time? This is the promise of wireless charging, a concept that seems ripped from sci-fi. But it’s not – it’s real, and it’s available today. Let’s look at the reality and see what this technology can and can’t accomplish.
How Wireless Charging Works
The term “wireless charging” usually refers to inductive charging. This technology uses a charging station that creates an alternating magnetic field. A device with the proper induction coil will receive energy from that field when it is placed nearby, making it receive power without a physical connection.
Cordless toothbrushes and other bathroom devices have used inductive charging for a long time. The technology has traditionally had problems with low efficiency and slow charging, but these were not considered a disadvantage for bathroom appliances that might be used for only a few minutes every day. Using inductive charging is safer, as well, because the conducting material is not exposed. Touch it with a wet hand? No problem.
Inductive charging is not magic. It needs specific hardware to function, and that hardware must be built into a device. Most devices do not have inductive charging coils built in to them, so a sleeve or adapter must be attached to enable inductive charging.
The Disadvantages Of Inductive Charging
Inductive charging relies on magnetic fields. These can be strong but often have a short range of effect unless an incredible source of magnetism is available (the Earth has a magnetic field only because it also has a huge molten metal core). Small inductive charging stations are no different.
Let’s use a wireless toothbrush as an example. You place it on the stand and it charges. The contact between your toothbrush and the stand is not responsible for charging, however. It just seems that way because the field used to charge the toothbrush is so weak that its range is best measured in millimeters.
Charge speed and efficiency remain problems, as well. Attempting to charge a device using induction charging just isn’t as efficient as a direct, physical connection.
And then there’s the inductive coil. Though small and becoming smaller, it’s still a sizable piece of kit relative to the space available in a modern smartphone, tablet or ultrabook. This is a problem that will diminish with time but is relevant to today’s devices.
Wireless Charging Comes To The Mass Market
The lack of a common standard is another reason why wireless charging never gained much traction in consumer electronics. It wasn’t so long ago that most devices still relied on Ethernet cords for data and mobile broadband was restricted to ridiculously slow speeds. Wireless charging did not seem important before wireless communications.
That has changed thanks to the Wireless Power Consortium and its Qi (pronounced “chee”) standard. The WPC is an industry organization sponsored by various companies all seeking a standard for wireless charging. Its members include every big name in the mobile market besides Apple.
I talked about Qi Wireless after attending CES 2012. I was able to see a number of working prototypes as well as existing products that used wireless charging. These prototypes and niche solutions are now becoming a reality is mass market products. Nokia, for example, recently announced is new Lumia 920 will have wireless charging built in. The less expensive Lumia 820 will have an optional shell that enables the technology.
It’s clear that there is a future for wireless charging. There’s a lot of industry support behind WPC and a desire to bring the feature to market. We’ll likely see a number of additional devices with wireless charging announced this year and next.
The Future Of Wireless Charging
Current inductive charging can be convenient, but the lack of range is a problem. It diminishes the technology to a convenience rather than a revolution.
Will this change? Maybe. There’s been plenty of research into the potential of long range wireless power and many different technologies have been used to achieve it. Lasers, microwaves and more powerful variants of inductive charging have been able to achieve longer transmission distances. Disadvantages have hampered wide-spread adoption. Tripping over a laser used for wireless power transfer, for example, could result in a vaporized foot.
It’s hard to say where a breakthrough in this field will come from. Apple is one candidate because the company has patented a device that can allegedly power devices at ranges up to one meter. The Wireless Power Consortium is also continually looking into better options. And then there’s Intel, who recently announced that it is working with Integrated Device Technology on a magnetic device that would be placed in a laptop and deliver power to nearby smartphones and peripherals.
Or a breakthrough could come from a small engineering company that’s barely known. This is a tough technical problem that will require both creative thinking and significant engineering know-how to solve. A major corporation may not be the first to find a solution.
Wireless charging has huge potential. This is why people have been working on it for well over a century. If we could move power without wires we’d be able to re-think not just consumer electronics but the infrastructure used by the entire human race.
Alas, we’re not there yet, but the renewed interest in this field brought by consumer electronics is appreciated. Perhaps the eternal quest of endless convenience can finally crack this technology wide open.