iPhone 15 Pro (Max) could be king of battery life

The iPhone 15 Pro through the more efficient A17 chip that is based on a 3nm process. 

The change could be one of the biggest steps Apple has made. 

2023 will see the latter start manufacturing silicon based on 3nm process

This year's Apple iPhone chip only managed to deliver up to 20 percent efficiency. 

The A17 is expected to bring improved processor and graphics performance 

Apple has kept both areas a little unchanged on the A16. 

Apple could also focus on improving the machine-learning capabilities of the chip. 

The iPhone 15 Pro and Pro Max are the only models that will be equipped with the A17 Bionic 

Apple is also working on an iPhone Ultra to replace the bigger Pro Max model.

It is believed to feature a titanium chassis and periscopic camera.