Since Apple released the iPhone 8, iPhone 8 Plus and iPhoneX that support fast charging in September 2017, USB PD fast charging has become popular, and it has gradually become a well-known charging method. The fast charging technology increase in charging speed is really impressive.
Apple's official spec shows that the iPhone XS, iPhone XS Max and iPhone XR all support fast charging, which allows the phone to charge 50% in 30 minutes. Compared to old 5W chargers, fast charging USB PD charges 3 times as much in 30 minutes.
So far, Apple has released 6 iPhones with fast charging, including the iPhone 8, iPhone 8 Plus, iPhone X, iPhone XS, iPhone XS Max and iPhone XR. But for fast charging of these iPhones, most people haven't aren't fully aware of the full capabilities. So on today's topic, let's talk about the fast charging abilities of the iPhone XS Max and what you should know.
Q1：First and foremost, what charging protocols does iPhone XS Max support?
We all know that the iPhone 8 and later models can support three charging protocols, namely USB DCP, APPLE 2.4A and USB PD fast charging.
The USB DCP charging protocol is no longer familiar. Take the iPhone XS Max as an example. The default 5W charging charger that comes standard with the phone uses this charging protocol. This is also the cheapest and simplest way to charge iPhone XS Max. Any charger with USB interface on the market can be implemented with a USB-A to Lightning cable. A non-MFi. Certified charging cable can also be used. Of course, the charging speed is also very slow.
The APPLE 2.4A charging protocol was first applied to the iPad, and the maximum charging power can reach 5V/2.4A 12W. However, this charging protocol is not the first application on the iPhone XS Max, but from the iPhone 6S and later supports this protocol, the charging power of the mobile phone can not be stabilized at 12W for a long time, and the charging power of each model will also be some differences.
Apple 2.4A charging protocol is extensive. Third-party chargers and power banks that support the APPLE 2.4A protocol are available on the market, and only need to be equipped with a USB-A to Lightning cable.
Finally, USB PD fast charging-
At present, the iPhone XS Max uses USB PD fast charging in the same way as before, and end-users need to purchase a USB PD charger and a USB-C to Lightning fast charging cable separately. According to the test results, the iPhone XS Max's PD fast charging power can reach more than 20W, which is greater than the previous generation models.
To sum up: In the case of USB DCP, APPLE 2.4A, and USB PD, the iPhone XS Max's protocol selection strategy is to use the USB PD fast charging protocol first, followed by the APPLE 2.4A protocol, and then finally the USB DCP charging protocol.
How fast is the iPhone XS Max using USB PD fast charging?
For the question of charging speed, it is always necessary to give an accurate answer after actual testing. The iPhone XS Max was tested by Inviolabs with the standard 5W charger and the 30W USB PD fast charge charger. The graph is as follows:
With the USB PD charger for 29 minutes, the phone's power reaches 50%, and it can reach 78% in one hour; it takes only 2 hours and 17 minutes to fully charge. In the case of the standard 5W charger, only 16% of the battery can be charged in half an hour, and the mobile phone can only reach 33% in one hour; it takes 3 hours and 42 minutes to fully charge.
For the iPhone XS Max, using the USB PD fast charge saves about 90 minutes of charging time compared to the standard charger. But the most important thing is that USB PD fast charging has a more obvious speed advantage when the mobile phone has low battery and needs emergency charging. (The speed is 3 times that of the standard 5W charger within 30 minutes. It is awesome), this is the charm of USB PD fast charging.
Q2: 50% for half an hour, why it takes more than 2 hours to become full?
The charging voltage is at 9V high voltage fast charge in the first 65 minutes, and 5V charging after 65 minutes; the charging current is kept above 1.5A in the first 40 minutes, that is, within 40 minutes before charging, charging power is basically above 13.5W, it is 2.7 times that of the standard 5W charger, and the power can quickly rise to over 70%.
Why need more than 2 hours to reach 100% power? We can also check with the curve changes. After the phone is charged for 40 minutes, the charging current drops linearly, and the charging current is almost zero in the next 5 minutes, the iPhone XS Max is in a state of no charging. In the next 30 minutes, the mobile phone is at 5W charging power; furthermore, because the mobile phone's power is saturated, the charging current is gradually reduced, occupying half of the whole charging time, reducing the overall charging speed of the phone.
Q3: Is iPhone XS Max fully supported for USB PD fast charging?
This question is also the most frequently asked. It is easier for everyone to understand that the 9V high-voltage fast charge belongs to the USB PD charging protocol, but there is always doubt about the subsequent charging voltage drop of 5V.
Although the iPhone XS Max is in a 5V charging state, there is USB PD communication between the mobile phone and the charger, which belongs to the 5V charging mode of the USB PD fast charging protocol. Therefore, for iPhone XS Max, in the case of charging with USB PD, it uses the fast charging USB PD protocol during the entire charge process.
To sum up, to use USB PD fast charging on iPhone, you need to have an 18W USB PD charger or higher, with a USB-C to Lightning cable. Remember that the cable needs to be certified by Apple MFI. Enjoy the speed.