To a generation raised on electrical appliances that needed a plug attaching before they could be used, wireless charging might seem like a remarkable advance.
Yet this method of energy transmission has been with us since 1901, when Nikola Tesla built a wireless transmission station in New York.
This isn’t new technology, but its incorporation into smartphones is being marketed as a key reason for consumers to upgrade – freeing us from the tyranny of cables.
And anyone who’s ever tried to remove an Apple charging plug from a wall socket will be glad the iPhone 8 and X incorporate wireless charging as standard.
But how does it work, and should your next handset include it?
A brief history lesson
After the Tesla Tower was decommissioned, experiments into wireless charging languished.
For much of the 20th century, electrical appliances didn’t need such sophistication.
Even so, the principle of using electromagnetism to transfer energy from an inductive coupling to an electrical device has long been touted as ‘one for the future’.
As technology caused devices to shrink in size, and new manufacturing techniques enabled the use of low-resistance materials like glass, wireless charging finally became relevant.
The Wireless Power Consortium celebrates its tenth anniversary this year, and in 2010 they established the Qi open interface standard that still covers many wireless devices.
Toothbrushes have used inductive charging for decades, but the first smartphone to deploy this technology was 2009’s Palm Pre.
Other manufacturers followed Palm’s lead, and a cursory scroll through any mobile phone brochure will reveal handsets offering cable-free charging.
Since smartphones and tablets tend to drain their batteries within 24 hours, the benefits of wireless recharging are especially pertinent:
- There’s no need to link the device to a wall socket with a cable – which is harder than it sounds with non-reversible micro USB cables
- No wear to sockets or the handset body – scratches and damage may arise if plugs are constantly being inserted and removed
- Aesthetics – a charging plate makes a stylish addition to any desk or bedside unit
- Multiple devices can be charged at once if the mat is big enough
- It works on the road – car manufacturers are adding wireless plates into vehicle interiors, so you won’t run out of battery during a day trip.
So do I need wireless charging?
Of course not.
It might be practical in the car (and more convenient around the home), but it’s hardly as important as 4G or a scratchproof screen.
Power transfers slowly if your phone isn’t centrally positioned over the charging mat, and it’ll only be 80 per cent as efficient as a cable even at peak transfer.
Wireless mats are far more expensive than basic cables, while different devices might not charge from the same mat.
You can’t move the handset or hold it while it’s recharging, and some aftermarket cases may interfere with this process.
Even so, wireless charging is a nice feature to have – and you don’t have to use it…
Image: Aaron Yoo