Even without being able to become a standard capable of covering all mobile phones in the market, wireless charging in smartphones has been among us for several years, and more and more, luckily, the brands that decide to add to the trend of adding this technology to your devices. After all, if the goal is to reach a totally “wireless” future, adopting wireless charging is something that most, but all smartphone manufacturers should carry out sooner or later. Wireless charging’s inclusion in phones such as the iPhone range has given wireless charging a new life
Contrary to what happens with fast charging, which is in an excessively fragmented landscape, the vast majority of smartphone manufacturers that have already adopted fast charging, have made through the Qi standard, which helps users to use universal accessories regardless of their device, as long as it is compatible with fast charging. This, in turn, makes understanding the operation of the technology, as well as the accessories that work and those that do not, and especially the mobile phones that are compatible, much easier to understand.
Wireless mobile charging: all the information
What is wireless charging and how does it work?
Several companies have been trying for years to ensure that the devices have the ability to charge “remotely”, without having to put the phone on a base to be able to charge. But since today these types of systems are still far from seeing the light, in this guide we focus on wireless contact charging technology ; the one that really works, and is included in all the mobile phones with wireless charging on the market.
As I said before, the vast majority of smartphone manufacturers have opted for Qi technology – called “chi” – wireless charging. This system was developed by the Wireless Power Consortium Organization, and is based on an electromagnetic induction electricity transmission system, which operates over distances of up to 40 millimeters.
With this in mind, it is easy to deduce that two different devices are needed to carry out the charging wirelessly: a base connected to a power source, and a receiving device that must be compatible with Qi technology. In the case of smartphones, the charger is the base or charging station, and the phone is the electricity receiving device.
Both in the charging base and in the receiving device we will find a coil – transmitter in the charger and receiver in the smartphone -, and when they come into contact they create a magnetic field through which the alternating current is induced to carry out the charging of the device – to learn more about it, it is advisable to learn the concepts of the Faraday Law -.
Since the two coils must be aligned for the load to be carried out correctly , it is common to see how in some charging bases graphic guides are used – latexes or boxes that indicate where to put the phone – to prevent misalignment from causing problems during the charging process. However, some wireless charger manufacturers choose to create their accessories under a system known as free positioning induction , which is based on the use of various coils located at different points inside the charging base to create an electromagnetic field that houses a larger area, and thus avoid any possible misalignment.
In general, the transfer of energy carried out during a Qi wireless charging process in mobile phones is between 0 and 5W. However, the system can also extend its power to 120W when the receiving device requires a greater flow of energy … for example, a laptop. Even so, in the market we can find wireless chargers that offer greater power, but given the inefficiency of such technologies – and yet Qi is a much more efficient standard than others, the loss of energy that occurs during the process of Charging is greater than if it is done by cable, and that is why wireless charging is usually never done at the maximum power offered by the charger.
This loss of energy also causes the charging process through Qi technology to generate more heat than wired systems, this being one of the main reasons why brands such as One Plus still refuse to introduce wireless charging into their phones.
Another of the peculiarities – which really is not so much – of most wireless charging systems, is that they require that the two surfaces of the charging base and the energy receiving device that come into contact, be made of a material non-metallic, since the metal would act as a conductor, and the energy emitted by the coil of the charging base would be induced to the metal body of the phone, thus generating more heat than normal and completely blocking the charging process. Hence, the vast majority of smartphones compatible with wireless charging are made of glass or plastic.
Currently the main use of wireless charging tech is in the mobile phone charging stands and mats, the Qi charging is starting to be utilised in other applpications such as warehouse robots and IoT devices. The future looks bright indeed for wireless charging.