How does wireless charging work?

How does wireless charging work?

There’s no escaping the fact that cables are a pain.

They get tangled up, feature a multitude of incompatible connections, and generally create a messy appearance wherever they’re deployed.

Yet until now, most electronic appliances and gadgets have needed power leads to remain operational.

Three cheers, then, for wireless charging.

First offered on the Palm Pre handset in 2009, inductive smartphone charging was popularised earlier this decade by Nokia and Samsung.

However, it’s only in the last couple of years that wireless charging has really captured our imagination.

Today, charging plates can be added to many new cars, while desks and tables across the land sport coaster-sized devices capable of recharging phone batteries without any leads.

So how does this technology actually work?

The appliance of science

After a few years of experimentation with wireless induction technology, hardware manufacturers settled on an industry standard known as Qi.

Not to be confused with the BBC quiz show, Qi charging involves generating an electromagnetic field in the induction coil mounted inside a base station.

Electromagnetic induction transfers power to the induction coil in an adjoining device, which then converts this energy into an electrical current.

Because the amount of energy being transmitted is relatively modest, base stations don’t cause interference with nearby electrical appliances like computer monitors.

However, the two induction coils need to be in close proximity to ensure power distribution occurs.

Moving a handset by a couple of centimetres can halt power transference, so it’s important to position the device carefully on a base station, and then try to avoid disturbing or moving it.

The benefits of wireless charging

There are many advantages to ditching those iconic white charging cables in favour of a wireless base station:

  1. Less wear and tear. Charging cables are fiddly, and it’s easy to try and insert them the wrong way up. This could scrape or wear the phone’s casing, reducing its resale value.
  2. Less risk of damage. Equally, incorrect attempts at inserting a cable might damage the charging points, potentially shortening the device’s lifespan or requiring repair.
  3. Simplicity. Instead of fumbling around plugging in unwieldy cables, you simply sit a phone on a padded plate that effortlessly (if rather slowly) restores battery life.
  4. Aesthetics. Not only is this an easier way to put juice back into your smartphone, today’s charging pads are more attractive additions to a bedside unit or table than a plastic cable.

In the interests of balance, it’s worth noting Qi charging takes longer than a hardwired cable, which could also charge a phone from any appliance with a USB socket.

A charging plate is less portable (and more expensive) than a USB lead, and some handsets don’t work on chargers manufactured by rival companies.

Nonetheless, given its many advantages, wireless charging is expected to become the norm rather than the exception in future.

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