Upgrade to IOS 16 causing rapid battery draining
I've had an iphone 8 for 2+ years. A few weeks ago I upgraded to IOS 16 and immediately the battery drain was noticeable, so much so that I must charge multiple times a day. Usually a full charge overnight lasts me the entire next day.
After the upgrade, I watch my battery percentage drain not by decrements of 1-2% like I'm used to but huge jumps within minutes.
Example: 98%, few minutes later, 92%, few minutes later, 83%, few minutes later 74%, etc.
The reverse is true too. When I reach 1%, I'll charge for a few minutes and it jumps to 30%.
So the way that the battery is draining doesn't make any sense. I have not changed my behavior in the way I use my iphone. The only difference is upgrading to IOS 16.
iPhone 8, iOS 16