IOS 11.2 7.5W wireless recharge test

The new iPhones 8 and X are the first to be compatible with the induction charging Qi standard, widespread in the market. But something was not ready for launch, which made Apple initially limit the power absorbed by the devices, with the promise that by the end of the year it would release to the full capacity of 7.5W.

This day arrived with iOS 11.2 and it is now possible to charge the device a little faster than before. And we tested it to see how much faster this load got.

First of all, it is necessary to understand well what has changed and what the consequences are.

Induction charging is usually slower than those made by cables, and this happens on all brands. This is characteristic of technology, as the energy loss in the induction process is much greater than that made with wires. So you can’t expect wireless charging to be as fast as that using the Lightning cable.

The only advantage of wireless charging is the convenience. You simply support the device on the base and it is already recharging the battery, without you worrying about connecting anything. When leaving the place, just take the device back as if it were on the table and leave, without bureaucracy.

It is important to know this, because we are not going to make comparisons between charging with or without wire, precisely because they present different proposals. The only comparison we will make in this article is before and after updating to iOS 11.2.

A matter of Power (W)

The new iPhones are compatible with the Qi pattern (read tchí), widely used in the market. This means that the user can buy bases of any brand and will work with the iPhone 8 and X (read ten). However, the power of this base is what will give rhythm to the charging of the device.

The new iPhones have already left the factory designed to accept a charge of 7.5W. But, for some technical reason, Apple preferred to limit this ability to 5W in the first few weeks after launch, promising to remove this limit in a system update by the end of 2017.


Accepted power

iOS 11.0


iOS 11.2


This means that with iOS 11.2 induction charges are faster, on bases that offer more than 5W of power. This detail is important, because if you bought a cheaper base of just 5W, nothing will change with the new system.

Testing with iOS 11.2

We tested the performance of wireless charging with the new iOS 11.2 and compared it with the results measured in the previous version of the system. For the best possible performance, we follow the following parameters:

  • we use the same 10W Qi wireless base
  • we use a 2A wall charger (in this case, the iPad) to connect the base to power
  • we use a single outlet, without extensions or other devices connected contemporaneously
  • the iPhone was not wearing any protective covers

Any of these elements can influence the loading time. If you have a base that supports 10W, but plugs into a wall adapter that provides only 5W, charging will not be optimized. Same thing if you plug into an outlet that is already being used by other devices, as the current in this case is shared.

With that determined, we measured the wireless charging on the iPhone X for two hours. And it actually turned out to be faster than the measurement on the previous system. See the graph to better understand the result:

Wireless charging performance on iOS 11.2 came very close to that of wired using the original charger that comes in the iPhone box (5W). Yes, we all know that it has always been considered slow, but once again reinforcing that we are not here making comparisons with wired loading, but the speed between two different versions of the system.

That is, we were able to observe a improvement wireless charging performance on iOS 11.2 from 10 to 20%, depending on the elapsed time. The longer it is loaded, the greater the proportional difference between the two versions of the system. This means that in the first 30 minutes the user will not see any great benefits between them, but after 2 hours the difference is much more significant.

Therefore, if you are using the new iPhones 8 and X and want to invest in a wireless charging base, the tip is to look for one capable of offering 7.5W or more of output, in order to enjoy faster charging. Of course, there are faster ways to charge the iPhone with wires (see here how), but for those looking for practicality on a daily basis, a Qi base may be a good choice.