The battery life on my 14 pro max is definitely better than my old 13 pro max. The 13 would still easily last me all day under moderate to heavy usage, but my 14 so far will be at 60-65% at the end of my 10 hour work day whereas my 13 would range from 40-45% give or take. This is without altering any settings in my 14, and I use the always on I just got an iPhone 14 Pro Max and I have seen a huge battery drain when using the camera. No matter if I just take a photo, or record a video, it will literally consume 1% of the battery for every minute I spend in the camera app. Therefore, the battery life of the iPhone 14 PM would be just 100 minutes if used intensively for taking pictures The iPhone 15 Pro stays cool to the touch for the most part, even when playing games. It can heat up when charging at random times, but it's not a consistent issue. Battery life is about on par with the iPhone 14 Pro Max battery life, and there doesn't seem to be much of an improvement. With the iPhone 15 Pro models, Apple added an Action N6LP.

iphone 13 pro vs pro max battery life reddit