Apple advertises that it will charge 50% in half an hour, but it is actually close. Here is the charging results of iPhone 8 Plus and iPhone 7 Plus in the same way.
iphone 8 Plus
iPhone 7 Plus
This in turn is the result of charging iPhone X, 8 Plus and 7 Plus until 100% of the battery is fully charged: 2 hours 5 minutes, 1 hour 50 minutes and 2 hours 32 minutes.
Now there are several numbers comparing new iPhone models. What about fast charging compared to regular chargers with 5-watt and USB-A-to-Lightning converters like on other iPhones? This is the result when charging in the usual way.
29-watt (left) USB-C converter and 5-watt (right) USB-A
You can see for yourself, fast charging saves up to an hour and a half compared to fast charging if you want to fill the battery. The experiment showed fast charging until the battery was full. IPhone X was slower than the iPhone 8 Plus, partly due to the battery of 2,716mAh compared to the 2,675 mAh of the iPhone 8 Plus.
See also: How close to iPhone 8 charging faster than iPhone 7?
In the last minute, fast charging takes 21 minutes while charging usually takes 23 minutes. Usually all fast chargers are slower at the last minute to avoid battery or phone damage.
The $ 70 is also relatively large for an adapter and cables for charging only, but it's really worth it if you need to charge fast, use a lot and don't have time to wait.