iPhone 15 Pro Max charging test: common myth around iPhone charging speed debunked،
And which charger should you buy to achieve the fastest and safest charging speeds?
This is what we seek to discover in our scientific study. iPhone 15 Pro Max charging speed test.
First, let's start with the statistics: the iPhone 15 Pro Max comes with a 4,441mAh battery and Apple claims it supports 20W charging speeds. However, we now know from previous versions of the iPhone that the actual charging speed supported is a bit faster than that.
So for this test, we used a 30W charger with a USB-C output coupled with the official Apple USB-C cable provided in the box with the iPhone 15 Pro Max. Here are the results of this load test.
iPhone 15 Pro Max scientific load test results
Does it really max out at 20W like Apple claims?
iPhone 15 Pro Max wired charging chart reveals support for faster charging speeds than Apple officially claims
We are running this test with a 1% load and you can see that during the first 17 minutes of the test the iPhone 15 Pro Max charges at a roughly flat rate of almost 26 watts.
That's faster than the 20W maximum charging speed claimed by Apple itself, so right off the bat we get confirmation that it actually makes sense to buy a faster charger than the official charger. Our choice would be a charger of at least 30 watts from a reputable brand, but even a 25 W charger would give you better results than the official one from Apple.
You'll notice, however, that this 26W charging speed is only maintained for around 17 minutes, then it gradually drops back down to around 21W. This second stage lasts around 30 minutes after the test begins.
Then we have another drop at 15W charging speeds, which is sustained until about 42 minutes into the test, and then we see a very dramatic drop that happens within a few minutes.
Conclusion
Apple's claim of 20W charging speed is an understatement, but iPhones nonetheless have some of the slowest charging speeds in the industry.
As you can see, on the last few percentage points it charges at very slow speeds, which is intended to preserve battery health in the long term. This isn't something specific to Apple, but it's a common practice across the industry.
In conclusion we can clearly see that fast charging only works when the phone is weakly charged and once it reaches a charge level of around 80%, the charging speed drops significantly and especially for the latter percentage points.