Ios 16.4.1 battery drain issue

Battery drain depends on the usage and the health of the battery an not on iOS.

Protect & Prolong life of your iPhone's Battery:

1. About the battery usage on your iPhone, iPad, and iPod touch ...
2. Batteries - Maximising Performance - Apple (IN)
3. iPhone Battery and Performance

Try some of these options too.

1. Avoid Screen Mirroring
2. Put on Low Power Mode
3. Put Auto Lock On (1 min):- with low power mode it will be 30 Sec
4. Put Auto Answer Off
5. Disable Push notifications for apps you do not use often
6. Keep your iPhone Face down to prevent notifications to light up screen
7. Enable Auto Brightness:- Settings > General > Accessibility > Display Accommodations > Auto-Brightness [Enable]
8. Manually lower brightness from Control Center
9. If you Want to watch continuous Video. Stream it on TV or a Monitor
10. Don't force close apps; Apps which are not on frontend screen are paused by the system to save energy. Apps require more energy to re-launch. Apps which are open in the background use large memory is a myth and quitting them is counterproductive
11. Location services to be allowed only while using the app
12. Set your iPhone to fetch email and calendar data from internet less frequently
13. Turning off Background App Refresh 
14. Charge before it drops below 20-30%
15. Try connecting to trusted Wifi where ever available in stead of Cellular
16. Enable Airplane mode in areas with bad cellular and wifi coverage. Your phone keeps trying for reconnection with the missing / weak network. This uses lot of energy
17. Switch off Wifi & Bluetooth while in Roaming or Not in Range
18. Enable "Wifi Assist" : Settings > Cellular or Settings > Mobile Data > Wi-Fi Assist [Enable]
19. Periodically Check your Battery Health (Settings > Battery > Battery Health)

I have a iPhone 11, that since I have it works a full day with 40% left when I go to sleep (most of my apps have always default no background update). Automatic updates = always off.

3 days ago I decided to update to 6.4.1 + fast update was right after that. And the battery drains suddenly while looking at it (battery health 84%). It's 11 am and already below 50% battery level. So don't tell me it's a battery issue or the app use. It's the OS update. Unacceptable!

There are major issues with a number of different models of IPhone since the 16.4.1 (a) update.

This forum is littered with posts complaining about the same issue, and instead of doing something about it you have a number of users of the forum posting the same copy and past "make sure you've tried this, put your phone into power mode".

AnglDevl wrote:

ios 16.4.1 may have solved previous issues

What issues has it solved? If you can list a few it will help others.

Same battery life not the same as before.

iPhone X here. Phone has been great for years. 16.4.1 comes out and my battery drains like a sieve. This is unacceptable.

Same to me as well.

Has anyone had luck with doing a factory set?