And what charger should you buy to achieve the fastest and safest charging speeds?
That is what we set to find out in our scientific iPhone 15 Pro Max charging speed test.
First, let’s start with the stats: the iPhone 15 Pro Max come with a 4,441mAh battery and Apple claims it supports 20W charging speeds. However, we now know from previous iPhone releases that the actual supported charging speed is a bit faster than that.
So for this test, we used a 30W charger with a USB-C output coupled with Apple’s official USB-C cable provided in the box with the iPhone 15 Pro Max. Here are the results of that charging test.
iPhone 15 Pro Max Scientific Charging Test Results
Does it really max out at 20W as Apple claims?
iPhone 15 Pro Max wired charging graph reveals support for faster charging speeds than officially claimed by Apple
We run this test from 1% charge, and you can see that in the first 17 minutes of the test, the iPhone 15 Pro Max charges at a roughly flat rate of nearly 26 watts.
That is faster than the 20W claimed maximum charging speed by Apple itself, so right from the get-go we get a confirmation that it indeed makes sense to buy a faster charger than the official one. Our choice would be at least a 30-watt charger by a reputable brand, but even a 25W charger would give you better results than the official Apple one.
You will notice, however, that this 26W charging speed is maintained for only around 17 minutes, and then it drops gradually to about 21W. This second stage lasts until about 30 minutes into the test.
Then, we have another drop to 15W charging speeds, which are maintained until around 42 minutes into the test, and then we see a very dramatic drop that happens over the course of a few minutes.
Conclusion
Apple’s 20W charging speed claim is an understatement, but still iPhones have some of the slowest charging in the industry
As you can see, the last few percentage points, it charges at really slow speeds, which is done to prevent the battery health over the longer term. This is not something specific to Apple, though, it’s a common practice across the industry.
In conclusion, we can clearly see that fast charging only works when the phone is low on charge and once it reaches about 80% charge level, the charging speed decreases dramatically and especially so for the last few percentage points.
