Wireless Charging and the Technology Behind It

Wireless charging is like a Wi-Fi system, transmitting electrical power instead of data. By utilising electromagnetic induction, devices can charge by being placed on a compatible wireless charging surface, eliminating the need for traditional cables. This technology is not limited to smartphones; it extends to tablets, digital cameras, wearables like smartwatches, and even electric vehicles (EVs).

The efficiency of wireless charging is approximately 70%, with energy loss primarily occurring as heat during the charging process. This phenomenon explains why devices may feel warm while charging wirelessly.

So, how does wireless charging work? Wireless charging primarily employs inductive charging, where an electric current is transmitted through an induction coil in the charger to create a magnetic field. This magnetic field induces an electric current in a corresponding coil within the device being charged. The entire process occurs without any physical connection between the charger and the device.

Induction charging is commonly used to power smartphones, smartwatches, earphones, and other consumer electronics, but it’s not the only type of wireless charging technology out there. Radio frequency charging employs radio waves to transmit energy, while resonant inductive charging works over bigger distances than induction charging.

Inductive Wireless Charging

Inductive wireless charging (or induction charging) utilises electromagnetic induction to transfer power over short distances. Although electricity can be transferred from the charger to the device without wires, typically the charger and the device need to be close to each other or touching. This means induction charging is what’s known as a ‘near field’ technology.

Qi Wireless Charger

What is Qi wireless charging? The Wireless Power Consortium launched the Qi standard in 2009. The standard relies on closely coupled electromagnetic induction, with the portable device placed on top of the coil on the Qi wireless charger. The advantage of the Qi wireless charger is that it can be used with any Qi-compatible portable device. For example, you can use a Samsung Qi wireless charger to charge an Apple iPhone.

Resonant Wireless Charging

Resonance, or resonant, wireless charging operates similarly to inductive charging but can work over greater distances. Resonance or resonant chargers work by using oscillating current in a highly resonant coil combined with a capacitor. Like induction charging, this creates an electromagnetic field. A second coil and capacitor (a resonant circuit) in the device operating at the same frequency takes the power and converts it back into electrical current.

Resonance charging is advantageous for applications where longer distances are needed between the charging station and the device being charged. One charger can also charge several devices at the same time. One disadvantage of resonance wireless charging technology is that it is more complicated than induction charging and requires extra components.

Wondering how to use a wireless charger? Wireless charging pads are designed to be straightforward to use.

1. Connect the charging pad to a power source.
2. Place it on a flat surface.
3. Position your device in the center of the pad with its display facing up.

Once aligned correctly, your device should begin charging automatically.

Wireless charging has revolutionised how we power our devices. Initially popularised for smartphones, its applications have expanded significantly:

• Consumer Electronics: Tablets, smartwatches, and earbuds are now commonly charged wirelessly.
• Electric Vehicles: Major automotive manufacturers are exploring wireless EV charging solutions that could eliminate reliance on traditional plug-in chargers.
• Industrial Equipment: Innovations are underway for wirelessly charging forklifts and other industrial machinery, enhancing efficiency in warehouses and manufacturing plants.

As Malaysia embraces technological advancements, wireless charging is poised for significant growth. Electric vehicles are a key area for development when it comes to the future of wireless charging. Wireless charging has the potential to make it possible to embed a wireless charging system in the floor of a garage, or in the road, doing away with the need for a charger using cables and plugs.

As wireless charging technology develops, manufacturers will focus on greater wireless charging efficiency and speed while dealing with bigger power outputs. And when it comes to resonance charging, the focus will be on charging across greater distances.

With the rise of smart cities and increased electrification across various sectors, wireless technology will play an essential role in providing safe and convenient solutions for consumers in Malaysia.