How Do Wireless Chargers Work (Qi Charging)?

The era of cables is gradually coming to an end and wireless technology continues to develop rapidly. The range of wireless headphones and speakers is constantly growing and also the wireless chargers for smartphones are indispensable in some households. Here on Naijaknowhow, we will look at the wireless smartphone chargers and what exactly ensures that our smartphones can be charged by placing them on that “magic” pad.

Magnets

Wireless charging in the first place is not a technology that was suddenly invented a few years ago. It has been possible for decades to charge devices wirelessly, but the applications were simply not used much. The main applications were charging stations for electric toothbrushes.

You simply had to put your toothbrush on the charging station without connecting any cable. This method of charging is then made possible by magnetic induction. We are not planning on providing you with traumatic flashbacks to chemistry and physics classes, so the brief explanation is that some form of magnetism is being used to transfer energy from the charging station to the smartphone. The power supply that comes from the socket is hereby fed through the copper wire in the wireless – yes, it sounds very ironic here – charger. This creates a magnetic field through the charger. This magnetic field, in turn, creates a current in the copper coil of the device on the wireless charger.

Finally, the coil converts the magnetic energy into electrical energy, which is used to charge the battery. In addition to this magnetic induction, there is also wireless charging with magnetic resonance. This works almost the same and the main difference is that with magnetic resonance there may be a distance of up to 45mm between the charger and the device. The charging distance with magnetic resonance may be larger, but this is a less efficient way to charge a device.

Qi standard

It goes without saying that your toothbrush and smartphone will not be charged in exactly the same way since your smartphone uses just a little more power and is used more often. Most smartphones and smartwatches today use the so-called Qi standard (pronounced “chi” from Chinese).

This Qi standard uses wireless charging via magnetic induction at a short distance (1.5 cm to be precise). There are smartphones that also support the less popular PMA standard, but iPhones, among others, only support Qi charging. You can compare this in a way with charging via a cable. If you place a smartphone with Qi standard on a charging station with PMA standard, just as little will happen as if you try to plug a micro USB cable into a USB C port. Just like adapters where you put a USB cable in, wireless chargers have a certain voltage.

“The higher the voltage, the faster your smartphone is charged.”

In general, the higher the voltage, the faster your smartphone is charged. This is where the major disadvantage of wireless charging comes up. Most smartphones that support wireless charging are still fully charged faster if you do this with the corresponding USB cable and an adapter with the correct voltage.

Safer

Despite the fact that in most cases wireless chargers charge your smartphone more slowly, there is certainly a future for the technology. In the US there are many public places, such as Starbucks and McDonald’s branches, where you can charge your smartphone wirelessly. The advantage is that you do not have to take a charger with you and that the Qi standard is supported by all wirelessly chargeable smartphones.

Moreover, it is also a safer option. In some places you will find charging cables that are already waiting for you, so you don’t need your own cable. Here, however, you run the risk that hackers can hack your smartphone via the USB cables while you are unsuspectingly charging your smartphone. This is possible because via USB cables, not only power can be transferred, but also data, so that hackers can gain access to your smartphone and all your data. Wireless charging, therefore, is significantly safer as only electricity can be transferred here. So you can safely place your smartphone on a public wireless charger without running the risk of becoming the target of a hacker.

Whether we really needed wirelessly rechargeable smartphones is a completely different question. I myself don’t mind plugging a cable into my smartphone. The disadvantage of wireless charging is that you cannot use your smartphone as easily as when you use the charging cable. Anyway, a wireless charger with a good design on your bedside table looks a bit better than a black or white cable.