Wireless charging or 'inductive charging' refers to the transfer of energy from one object to another through an electromagnetic field.

Put simply, wireless charging requires two coils of wire, a device (to charge) and a charger to induce current, with one coil of wire in the device and another in the charger.

© iStock/Frenky362
© iStock/Frenky362

An alternating current reaches and passes through the coil in the charger which is then transferred to the coil in the device.

This current develops fluctuations within the electromagnetic field, which results in the device charging.

The closeness of these two coils creates a transformer (an electrical device that transfers energy) and thus, wireless charging is born.

Who is using wireless charging?

Qi is the leading global wireless charging standard that most smartphones comply with. Others include the Wireless Power Consortium, the Power Matters Alliance and the Alliance for Wireless Power.

Using the method of induction, smartphones can charge by being placed on wireless charging pads with no cables from the phone to the pad in sight.

Most new (ish) smartphones will have wireless charging capabilities built in but if not there are some cases that house wireless functionality. But the wireless charging potential doesn't end there.

Cafes, restaurants and cars are all making moves towards wireless charging.

Starbucks has integrated wireless charging throughout many of its US stores and started to introduce that over in the UK, while McDonald's has also rolled out wireless charging in some of its UK restaurants as part of their new ‘experience of the future’ restaurants.

And wireless charging can even be seen in large retailers such as IKEA that offer a whole range of furniture with wireless charging capabilities built in.

Advantages and disadvantages of wireless charging

From a user perspective, wireless charging is extremely easy to use, charging your phone by placing it on a table probably couldn't get much easier. 

What's more, wireless charging is safe as the internal coils are protected and sealed, making use in damp environments such as the bathroom and wireless electric toothbrush charging possible.

In fact, you're more likely to suffer an electric shock via a traditional phone charger than a wireless pad because there are no exposed conductors.

However, for devices that run on lower frequency, charging will be slow. To add to that, the output of heat is higher than traditional charging so if using a wireless pad, it's wise to place it on a heat resistant surface.

What's more, wireless chargers cost more than traditional ones in both manufacturing and customer sales and they must be in full contact with the charger at all times, making it more restrictive than a wired charger.

So is it really wireless?

Sort of. While we can't see any external wires connecting the device or smartphone to a charger, there are wires connecting the wireless charging pad to a power supply. But for some, this is not true wireless charging.

What's the future of wireless charging?

There is true wireless charging coming, it's just not certain when. 

Energous is a licencing company behind WattUp™ which transmits energy (charge) to devices like Wi-Fi to WattUp-enabled devices. A device can be up to 15 feet away from a receiver (wireless charger) to receive enough energy to start the charging process. 

So, while the future of wireless charging isn't totally clear, it is an area attracting big investments from some of the world's largest companies. It's surely only a matter of time before true wireless charging is available for all.