Wireless charging has quickly become a popular feature for charging devices. Did you know the technology that enables it dates back almost 130 years? IHS, a research firm in London, estimates that the wireless charging market is expected to swell to one billion devices by 2020. In today’s post, we’ll explain how the technology works, and while it has suddenly become popular.

Some History

Michael Faraday, an English Physicist, discovered the underlying magnetic and electrical principles that resulted in induction charging in 1831. Induction charging transfers energy wirelessly between two receivers. He was able to use a liquid battery to send an electric current through a small coil. When it transferred to a larger coil, the magnetic field changed, causing a momentary voltage in the small coil.

Nikola Tesla used Faraday’s principles to further the idea of transferring energy through the air. He was able to create a magnetic field between two circuits or a transmitter and a receiver. Below is a video from the Griffith Observatory in LA where Tesla’s prototypes are held.

How It Works

Modern devices use the same induction charging principles today. Inductive charging transfers energy from the charger to a receiver in the back of the device through electromagnetic induction. The charging pad has an induction coil that will create an oscillating electromagnetic field. The coil in your device will convert that magnetic field back into electricity to fuel your battery.

The bigger a coil is within the charger, the further you can be from it and still charge your device. There are two standards for wireless charging, and most phones support both:

  • Qi Standard: Standard in smartphones. Each device can support between five and fifteen watts.
  • Resonant Standard: This standard enables users to charge their device from fifty millimeters away. While this may not seem like a great distance, it means you can through your phone on a charging pad without its perfect alignment. It can also charge multiple devices at once.

Drawbacks

Even though technology is over a century old, it still has limitations. To begin with, some chargers require precise placement for the wireless charging to activate. Secondly, some cases will prevent the ability to wireless charge. Another drawback is that you cannot use the device while it’s charging. Wireless charging also takes longer than plugging the device into a wall charger.

Is It Worth The Hype?

Utilizing a wireless charge will mean using more energy and as a result, a higher electric bill. This is because it is less efficient. Any loss of energy will take the form of heat, which can wear on your battery over time.

The Wireless Power Consortium says that 30% of the energy is wasted per charge. This could amount to pennies on your electric bill. However, the environmental impacts can be more severe. It is estimated that all the current smartphones in the world used 900 billion watts of electricity per year. If all of these phones use wireless charging the energy used would increase to 1.13 trillion watts.

The energy wasted would equate to 225 billion watts per year which could power about 35,000 homes. It also produces roughly 100,000 metric tons of C02 pollution per year, according to the California Energy Commission.

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