Confirmations on battery improvements come from Tom's Guid and that he has carried out tests that should simulate use in real life. The reported data are 14 hours and 42 minutes with a single charge; a similar test carried out on the iPhone 13 Pro Max showed the data of 12 hours and 16 minutes. The US site in the ranking of smartphone batteries, now indicates iPhone 14 Pro Max in second place, ranked after the Asus ROG Phone 6 Pro which showed a battery life of 15 hours and 30 minutes with these tests.
In the tests of Tom's Guide the iPhone 14 Pro Max has “drained” 30% of batteries in 5 hours of intense use (downloading apps, listening to music, taking photos and shooting videos). As for charging, Apple reports that fast charging allows you to get to 50% in about 30 minutes using a 20W or higher power supply. As always, these latter tests depend on settings and environmental conditions and actual results may vary; Tom's reports of a charge that goes from 0% to 42% in half an hour with the Apple 20W power supply. The Galaxy S22 Ultra in tests reached 58% charge in half an hour using a 25W power supply and OnePlus 10 Pro reached 55% in 15 minutes, thanks to the 65W power supply.
In addition to the A16 chip, improvements to the battery are also due to the OLED display which when it can do so takes advantage of the 1Hz refresh rate (against the 10Hz of the iPhone 13 Pro Max) and various energy efficiency technologies.