Why is my iPhone 7 draining fast?

Question

iPhone

The iPhone started to sit down literally instantly
. I'm not an undemanding user, call and that's it, but he sat down from 7 in the morning with a 100% charge to 11 by 60%
What could be the problem?
Tips "brightness slider less" not needed

Answer 1

Reduce brightness (yes, yes, it is)
Disable interface animations (reduce motion)
Disable animated splash screens (if installed)
Reconsider the need to keep bluetooth on, etc.
Reconsider what background services do what (geolocation, data synchronization, etc.), what eats traffic and resources.
...
And many more small actions that need to be done once, even at the very beginning of using the phone, and as new applications are installed. Perhaps some application is constantly stirring up something in the background. Perhaps something is constantly trying to connect (looking for devices, etc.), for example bluetooth. If you have a Mac and you use handoff, it also eats, and if there are problems with connection stability, it can eat noticeably.
Google it, lots of info.
Still go through a couple of full charge-discharge cycles, sometimes it helps. Magic, but still.
If nothing helps - stomp to the service.

Answer 2

> call and that's it
Then it's better to take the Nokia 3310 - it holds the charge longer and, as a nice bonus, it doesn't break so easily.