Some smartphones offer a wireless charging system. Indispensable for some, useless for others, this type of loading does not convince everyone, but a question remains in suspense: how is the transfer of energy possible without cable?

Fast charging and electromagnetic induction

To fully understand how wireless charging works, you need to become familiar with the concept of the electromagnetic field and, more generally, electromagnetic induction, a technology you may already know with your cooktop in the kitchen. What is the link between an induction hob and a smartphone, you may be wondering? Electromagnetic induction is a system of energy transfer, it can then be stored, as is the case of the smartphone, or used.

How does this energy move? It’s a question of strength. Imagine two people holding a tightrope: if one decides to make waves with the rope, the other will get waves. This is a very schematized way of summarizing the electromagnetic induction system: a force sends energy from one point to another. Your base (powered by electricity) transmits energy to the smartphone via electromagnetic fields. Then, sensors on the smartphone are responsible for recovering energy and channel it to the battery for storage.

How is the loading speed calculated?

Everything is a question of strength. Since the energy is transmitted via electromagnetic fields, the speed depends on these fields. The bigger they are, the faster the loading will be. The problem is that it is not possible to make huge fields because the smartphone, by its material form (metal etc), causes limitations.

Your smartphone has a limited transfer speed, the voltage is specified by the manufacturer. The charger also emits power at a regulated speed, as you will see below.

What is Qi?

Qi is the best known wireless charging technology. It is not reserved for a particular manufacturer, in practice, all manufacturers can use it on their device. Samsung and Apple are probably the most famous of them. Qi seeks to standardize the wireless charging technology, for this, it involves several safety rules that must be strictly adhered to. Among these rules, we must mention the power of the devices, which obviously plays a role in the speed of loading.

Thanks to Qi, wireless charging technology has made considerable progress. The charging speed has increased considerably, and the electricity does not lead to any more heavy heating of the device. Note that Qi does not only use electromagnetic induction charging technology but also magnetic resonance technology.


Is my device compatible with induction charging?

Maybe you want to give up the cable load and opt for wireless charging. A question arises: Is your device compatible with this technology? If you have a high-end smartphone Samsung, ie a Galaxy S, then your device is compatible and Samsung offers its own charger. The new iPhone, ie from the iPhone 8, is also compatible with wireless charging, if you have a newer iPhone you can also use wireless charging but you will need a receiver such as the QInside Qi2001. Many Lumia, Motorola, Xperia and HTC smartphones are also compatible with Qi technology. Many Nexus are synonymous (Nexus 4, Nexus 5, Nexus 6, Nexus 7, Galaxy Nexus).

If your smartphone is not natively compatible with wireless charging technology, there are alternatives. Simply plug your smartphone into an adapter, it will receive power and transmit it to the smartphone using the cable.