No wires no tangles

The growing trend of wireless charging

By Gabriela Ehrlich, Antoinette Price

The idea of charging up our gadgets without cables is not so new. Back in the early 90s a wireless charging toothbrush was introduced at a dentistry convention in Florida, US. But the commercial application of wireless power transfer (WPT) goes back to the work of Nikola Tesla in the early 1900s.

wireless phone charger Wireless phone charging

The gradual growth of wireless power transfer

Over the last decade technology advances have led to the rapidly growing use of consumer electronics. This in turn has increased the interest in WPT.

Several industry-led consortia are developing industry specifications in the WPT space. With so many gadgets and cables needed to frequently charge multiple electrical and electronic devices, wireless charging is expected to prove highly convenient for consumers. Ultimately, WPT will allow users to recharge any portable device reliably anywhere, anytime without the constant burden of carrying and deploying different charging accessories for each of them.

Wireless charging in the IEC

In the IEC, work on WPT is split into two distinct Technical Committees (TCs) because of the wide variation in the power demands of various devices and systems ranging from cars to smartphones.

IEC TC 100/Technical Area (TA) 15: Wireless power transfer, is in charge of developing international publications for multimedia systems and equipment, while IEC TC 69: Electric road vehicles and electric industrial trucks, prepares the International Standards needed for the wireless charging of electric vehicles but also scooters and buses, among other things.

Additionally,IEC Subcommittee (SC) 21A: Secondary cells and batteries containing alkaline or other non-acid electrolytes, prepares International Standards for batteries used in mobile applications and electric vehicles, as well as for large-capacity lithium cells and batteries. These Standards concern tests and measurements, design and manufacturing recommendations and safety requirements. They are essential for the battery industry as it develops new products and chemistries.

Delivering new levels of convenience

The benefits of transferring power wirelessly are many, and apply not only to consumer electronics. They include:

  • Greater convenience for charging everyday electronic devices
  • Reduction of e-waste from multiple chargers  and a decrease in the number of external power supplies needed to charge different devices
  • Safe power transfer to devices that need to remain sterile or hermetically sealed
  • Robust and consistent power delivery to rotating, highly mobile industrial equipment
  • Delivering reliable power transfer to mission critical systems in wet, dirty and moving environments

Charging around the city

The application of WPT is continuously expanding. For example, cities are installing wireless-charging or induction-charging systems to make their transport systems cleaner and increase efficiency, for example:

  • drivers no longer need to plug into a charging station, removing the need to carry cables in the first place
  • batteries for induction charging are much lighter than those that use  cables
  • buses need less on-board energy storage, which reduces their weight and facilitates design and production

On your e-bike

Though still accounting for less than 5% of the total number of conventional bikes sold, in 2013, sales of e-bikes totalled 410 000 units in Germany, 440 000 in Japan and about 173 000 in the US (out of a total of about 15 million bikes sold there). It is estimated that about 200 million e-bikes are on the road in China and scooters and motorbikes including electric power two-wheel vehicles are gaining in popularity.

This trend will spread to other regions, such as Europe and North America, as more advanced machines are introduced to these markets.

The price of e-bikes is predominantly determined by the battery chemistry used. As the technology improves, costs will decrease. (See the full story in the May 2015 e-tech)

Moving slowly toward a wireless future

While progress is being made, there are still a number of hurdles to overcome before inductive surfaces can be found everywhere, making it easy for consumers to top up their devices wherever we are.

According to a survey by IHS, a company providing insights, analytics and expertise in business, as more key brands commit to the technology, which they roll out with their products, such as smart phones, the adoption of wireless charging is growing, even if slowly. However, as issues such as cost, charging speed and the ability to charge multiple devices on the same surface are ironed out, this form of charging looks set to take off. IHS predicts that by 2019 wireless charging for wearable technology alone could be worth between USD 1 and 1,2 billion.

Table mat charger Table mat charger
wireless phone charger Wireless phone charging
Conductive charging Conductive charging