iOS 15.5 is very annoying. Battery is draining so fast . Please do something to fix it. I am facing definitely in my professional work place.

Hello ~ In addition to *frazzm737’s* excellent information take a look here:

About the battery usage on your iPhone, iPad, and iPod touch - Apple Support

Check the iPhone battery health and usage - Apple Support

Important check the battery health as your battery may be below 80% and would need replacing.

~Katana-San~

Hello ~ Try this:

Force restart iPhone - Apple Support

~Katana-San~

This is a user forum. You are not speaking directly to Apple. We can only offer suggestions which may help. Have a look at this link...

The last update killed my battery! - Apple Community