US Edition Wireless charging is set to be a major theme at this year's Mobile World Congress (MWC) in Barcelona, with many of the big smartphone manufacturers including Samsung, LG, Motorola, Nokia and Apple investing in the technology. But what is it and how does it work?
Wireless charging (also known as inductive charging) uses an electromagnetic field to transfer energy between two objects. Inventor Nikola Tesla was the first to demonstrate wireless power transmission in 1891, when he succeeded in lighting electric lamps without wires.
It took over a century for the technology to find its way into the mainstream, but over the past few years wireless charging has finally emerged onto the consumer electronics market.
Some smartphones and smartphone accessories now have wireless charging capabilities built-in, and the technology is being integrated into all sorts of devices, appliances, public spaces and even vehicles, as companies look to make power cords obsolete.
For example, wireless charging pads can already be seen at around 50 McDonald’s locations in the UK, thanks to a deal between the fast food chain and Aircharge, and Starbucks also offers free wireless charging stations in 10 cafes in the UK.
Most of these commercial products use the magnetic-inductive method of charging, which involves coupling a device to a physical dock. If you have ever used an electric toothbrush or shaver, for example, then you may be familiar with this type of inductive charging.
The technology requires two coils: a transmitter and a receiver. An alternating current is passed through the transmitter, generating a magnetic field. This in turn induces a voltage in the receiver, which can be used to power a mobile device or charge a battery.
Apart from the obvious benefit of removing the need for power cords, wireless charging has the advantage of being more durable (there is significantly less wear and tear) and more eco-friendly (there is no electronic waste, and energy transfer is non-radiative).
However, there are also some disadvantages to wireless charging. For example, it can be slower, less efficient and more expensive than traditional wired charging – although newer approaches reduce transfer losses and improve speed through the use of ultra thin coils and higher frequencies.
One of the goals of the consumer electronics industry is to provide consumers with the ability to use one wireless charging dock that is compatible with all the devices they already own, as well as all the devices they buy in the future.
To this end, the industry has set up three organisations that are working to standardise wireless charging technologies: the Wireless Power Consortium (WPC) and its Qi standard, the Power Matters Alliance (PMA) and the Alliance for Wireless Power (A4WP).
As well as consumer electronics companies, brands from a wide range of industries – such as semiconductors, mobile services, automotive, furniture, software and others – have joined the effort and are working closely together.
Standardisation would allow the ecosystem for wireless charging to grow and mature rapidly. People would be able to charge all of their devices wirelessly in restaurants, airports, public spaces, cars and living spaces, freeing them from the burden of carrying their power cords.
It is expected that 2015 will be a landmark year for the growth of wireless charging, as the technology begins to appear in more and more public places. As MWC kicks off in Barcelona tomorrow, watch out for many more announcements in this space.