iOS 16.5 is draining my iPhone battery

Can confirm: I performed a DFU (Device Firmware Update) and my problem is now solved. Prior to the DFU, not only did I have the battery drain issue, but my phone also ran warm. After the DFU, my battery is back to "normal" and my phone runs at a "normal" temperature.

As to my situation, I did NOT know what a DFU "reset" was, so I performed a search. There are several YouTube videos that explain clearly how to do it, so I just followed those. My steps were:

1. Perform a backup. I backed up my phone to my Mac, but you can use iCloud too. What I do NOT know, is if you can perform a DFU without a Mac. I suspect you cannot, but someone else with more knowledge can chime in. NOTE: my iPhone backup was encrypted and as it were, I had no need to use the backup for a really long time. I could not, at first, remember my encrypted backup password. It took me several tries to get it right. In light of my experience, I strongly advise you know what it is if you have an encrypted backup.
2. While my backup was performing, I watched a DFU "reset" tutorial on YouTube a couple of times.
3. Once my phone was backed up, I performed the reset. I got it on my first try, but it may take several tries to get the button combinations and timing just right.
4. Once I entered DFU mode, I selected "update" as opposed to "restore".
5. Once my phone was updated, I restored it from the backup I just made.

As mentioned, my problem has since been resolved.

I have to correct myself. I was able to fix the problem but it really requires wiping the phone and restoring a backup.

Before that, I just 'hard rebooted' the phone via vol up, vol down and pushing the power button. That is, no wipe, no restoring via backup.

The battery drain has been gone ever since. On that note, it also proves that Apple's statements are just wrong. It's obviously an error caused by their update.

I wanted to provide an update: The battery drain issue has been resolved with version 16.5.1.

Your phone is just doing background operations after the update. It will do this in the background when the system recognizes some idle time. The amount of time it takes to complete will vary on how much work it is doing and how much idle time it has to do it. This happens after every update with the exact same draining battery reports. Here is an article written a couple of days ago about the 16.5 update.

https://www.macworld.com/article/1932749/no-ios-16-5-hasnt-killed-iphone-battery.html

There's definitely something going on with 16.5 beyond the normal "battery is worse for a few days after update".

My actual use is always very lite - no social media, almost no streaming video, mostly audio books, a couple dozen text messages and other minimal tasks. Previously had to charge every day and a half or so.

I updated my 13 mini +2 weeks ago and now I have to charge 2 - 3 times a day, instead of once every 1.5 day or so.

Same usage as before, or actually using it less since as others have noted it gets excessively hot doing only basic tasks. I've gone through all the normal steps that others outline to save battery, optimize, etc. with essentially no change. Overnight I was losing +40% with the phone doing nothing. Even putting it in low power mode and killing all running apps it would still lose 30%. Looking at use by app in the morning shows 0 screen on time 0 screen off, no apps but still down 30%. Battery health is 98% so that's not the issue.

However...It doesn't affect everyone. My wife's 13 and my son's 2020 SE seem fine. So I get it when some people may be skeptical. But that doesn't mean this isn't happening, or that it's the same thing that happens every update where the device just needs to settle in/re-optimize, or that this is just one or two people. Snarky comments that it isn't happening to you and we just have to wait a few days don't change that. As stated by myself and others, this is going on for weeks after applying the update, and I've seen enough comments here and in other forums to know that while it may not be a huge number of devices impacted, it's enough to be an actual issue.

Speaking for myself, I don't expect a solution here - at this point only Apple finding the problems and issuing a fix will resolve it. But for that Apple would need to know about the issue, so reporting the issue to them directly is probably the only way. I reported the issue with as much detail as I could, but unless others do as well it won't mean anything.

FIXED!

Reset trough DFU completely fixed this annoying issue

maybe you need to restart and check again

Looks like Apple may be posting a fix before the 16.6 release goes live. Search online for ios 16.5.1 - it is being reported that they may push that out for some specific issues including battery drain.

I can't confirm. I have reset the phone several times (iPhone 13; combination of Volume Up, Volume Down, hold Power Button for 10+ sec until Apple logo appears).

Sometimes it helps temporarily but the drain starts again quickly.

Example: I was working remote today and was home all day. I barely used my phone (24 min screen time) and right now at 9.30 pm German time my phone is below 20% charge. Before 16.5 it was at >80% at the time.

I have no new apps or changed my behavior in any way. Something's not right.

I have also read several well numerous posts online some of them from individual some of them from big magazine type websites who say that you up to you go in your settings and toggle this or that off or they say that oh gosh, don’t worry about it because every time Apple pushes out an update there are some glitches or problems right at first I’m telling you I’ve had this update for over two weeks and the battery drains really bad and right now I’m holding in my hand I’m charging it because it went down so so far and I can barely touch the phone. It’s so hot.

So Apple, if you’re listening, we’re not crazy it’s not in our user toggle of settings you did something wrong at Apple. You need to fix it and fix it fast or I’m just gonna throw this phone away and go get a Samsung.

I don’t care what these people say about all go read this article it’s just gonna happen in the first few days after an update no you’re Schilling for Apple. It’s been over two weeks and my phone is still draining very fast and gets very hot. And my phone is a less than one year old iPhone 14 Pro.

I'm on an iPhone 13 Pro running 16.5 with 98% battery capacity, and with just light usage the battery is draining very fast. For example, Battery Activity shows 15 minutes of Mail as the top usage, yet after starting the day with a fully charged battery, it's in the single digits by 5:30 pm. Pre-16.5, I'm wasn't even down to 50% by that time.

Thank you. That summarizes the problem perfectly. And I'm also getting annoyed by all the comments of "it takes a couple of days after an update". It's like the IT guy asking you if you have tried switching it off and on again. YES, a dozen times already.

I've applied EVERYTHING that is mentioned online: switch off updates in background, disable push, disable this, disable that. Switch to power saving mode. I even reduced motion.

All to no avail. I can leave the phone lying around all day in power saving mode and not have a second of screen time and it will drain 6% per hour. If I did that with 16.4, I was left with 85% battery at the end of the day.

It is definitely a problem with iOS 16.5

Ever since the 16.5 update, the power consumption during idle hours has increased from 5-6% to approximately 15% for every night sleeping time idle. Apart from this unusual usage during idle periods, I haven't observed any other abnormal battery consumption patterns. My phone is 14 pro max.