iOS 17.2.1 Battery Drain

It took my phone out completely. Finally got it restored and now battery drain. Usually in my morning routine I use 5-8% of battery life, I am currently down 27% and haven’t even finished morning stuff.

I have the exact problem with my SE2020. Battery used to last 2 days but now after 17.2.1 without using it and leaving it on standby it drains right down and into the red. My battery health is 100% as the phone is not very old. When Apple sort this, they better, I will not update my iOS anymore.

I have four Apple devices and my wife’s iPhone SE 2020 is fine with no issues, that is because she hasn’t updated from 16.4.1. The Wife is always right as they say.

Please sort it out soon Apple for your loyal customers.

17.2.1 definitely has issues. Please apple release an update to fix asap. Today for the first time in 3 years my phone battery died in just 6 hours!

ios 17 had been very good with battery life until this rotten egg update

I have a 12 Pro Max which was fine until this morning.

I woke up to the notification that the phone had updated to 17.2.1.

My I used my phone for a good 2 hours today which led to losing roughly 25% charge, so still 3/4 full.

I drove home.

When I looked at my phone, it was suddenly at 25% charged. So 50% disappeared.

I charged it. Drove somewhere else, phone on car charger. Battery keeps draining WHILE on the charger. The charger shows that it is working.

I now restarted my phone and googled this.

will charge it fully and see what happens.

my phone was fine. This is absolutely due to the update

Do you have a problem related to the fact that the phone loses a couple percent of its charge within a minute in standby mode after a little use.

For example, I used the phone for a while and turned off its screen when the charge level was 30%, but then when I started using it again after a couple of minutes, the charge was already 28%

I understand it is entirely normal to have quicker battery drain immediately after an update. There are a lot of update processes that continue to go on in the background after the software update. I understand thing improve after that. That's one reason why I hold off updates if I'm going out of town.

https://www.zdnet.com/article/battery-bad-after-installing-ios-17-try-these-7-tips/

Mac.newby wrote:

ok wrong word. They were never started - and then suspended. They are available for dispatch by IOS - right?

Yes. That is a list of apps that have been used; it is only a list. It is not apps. Here is the long answer:

I’m going to try to dig into what the App Switcher is. This is based on my knowledge of operating systems in general and how virtual memory works; it probably is not 100% accurate, but should be close. 

The App Switcher does not contain apps. Essentially it is just a list of apps that have been used. I’ll call them “stubs”. Each stub contains the ID of the app, and the last state the app was in when it last ran. If the app has a code segment in RAM it also contains a pointer to that code segment. But the stub is very small, probably just a few hundred bytes (if that much). When you relaunch an app either from the Home screen or the app switcher the list is consulted, and if the app is in the list either the code segment is activated so it can resume where it left off, or if it is swapped out, it is reloaded so it can resume where it left off.

If the app is not in the list the app is started from scratch; its entry code segment is loaded, and it must run its initialization code, open its resources and then go on to its working code. This takes longer than just activating it from the app switcher, and uses more energy than just activating it from the app switcher, so for this reason killing apps unnecessarily uses more energy than just leaving them in the app switcher list. Probably not a lot more, but some.

But as they are just stubs, none of the apps in the app switcher are “running”. 

When you kill an app in the app switcher the next time it is needed it must be reloaded as I described. But also consider what happens when you kill an app. If you first exit to the Home screen, then kill it, you probably won’t do any damage, because exiting to the Home screen allows the app to save its state in storage and be in an idle state when you kill it.

Some people kill an app by going to the app switcher and killing it while the app is still “running”, rather than exiting to the Home screen first. This can have unpredictable results, because killing an app stops it RIGHT NOW, right in the middle of what it was doing. This can result in lost data. The most egregious example of this was when the “unsend” feature was added to the Mail app. A lot of posts complained that their mail never sent, and it was because they killed the Mail app from the App Switcher without waiting for the message, which was only in RAM, to send. Apple DID fix this, by saving the message to the Outbox as soon as Send was tapped, and before it was sent. The same thing can happen with Messages, if you exit directly from the app switcher, and it is also true for many 3rd party apps.

OrangeGrapefruit wrote:

Second and most importantly, Apple is known the slow down the devices when it’s time to hard push upcoming new ones. Most of the time they use the “security” updates to slow the devices, since these updates are installed more often than not.

No, in fact they are not known for that. At a point in the past, Apple started throttling phones that had dying batteries to prevent those phones from dying unexpectly. They got in trouble for not adequately publicizing that. If that happens to your phone, the solution is to replace the battery. Buying a new phone is not required (unless your phone is really old).

All lithium-ion batteries lose capacity over time. There is nothing Apple can do to change that. And security updates are to counter new security threats.

Same issue… just be glad you don’t have a 13 mini…

The battery drain is unreal.

I am also having the same issue with my iphone 14 pro when I updated to ios 17.2.1. This is the worst update ever! My battery drains 1% per minute!

Glad I didn't updated my iOS, I am using iOS version 15.5 on iPhone 13 and its giving me good battery life.

my 13 pro, batt drain, also always hot everytime i use, a lot Of bugs too. Please fix it ASAP ❤️

Thought 17.2.1 will fix the battery drainage issue its not doing so. Apple please fix this its becoming a nuisance.

iPhone SE 3rd gen here. Battery health 96%. Updated the day after release, and suddenly on 1/1/2024 I'm hit with the same. Battery settings show 100% usage at all times, daily battery life has capsized and phone constantly runs hot. In my case, the culprit seems to be Messages, out of nowhere, just chewing through battery in the background. This is the kind of stuff I always read about but have never experienced.