The technical specifications of the iPhone 13 family indicate that, in order to achieve the fastest charging speeds, it is necessary to use a 20W charger, as was the case with the iPhone 12.
However, it appears that the iPhone 13 Pro Max can achieve faster charging speeds than its predecessor, the iPhone 12 Pro Max, although Apple didn’t mention this during the presentation or on the web.
In a video uploaded to ChargerLab, the iPhone 13 Pro Max is shown being tested with several chargers of different wattages.
Based on the numbers that appear, The iPhone 13 Pro Max can achieve charging speeds of up to 27W when paired with a charger of at least 30W.
However, the video shows that the speed fluctuates, so it’s not at a constant 27W. Still, it appears to be faster than the iPhone 12 Pro Max, which has a limit of around 22W, even when paired with a 30W charger.
The video also shows the phone paired with even more powerful chargers, up to 100W, but it doesn’t really seem like there’s much difference beyond 30W.
So if fast charging is a priority for you, investing in a good quality 30W charger or higher might be a good idea.