iPhone 8 Plus huge battery drain on iOS 14.8 (vs iOS 14.4)

[Marinier]

This post aims to keep from mistakes those who has iPhone 8 Plus on iOS 14.4 (like I have recently been).

I am a happy owner of iPhone 8 Plus (256 GB) since October 2018 and it performed fantastic on every iOS including iOS 14.4. Issues emerged after I updated it to iOS 14.8 two days ago. Now I see that it was my dumbest decision as Apple user.

My iPhone 8 Plus has 80% health of full battery capacity now. By the way, battery health decreased from 100% to 80% (step-by-step side October 2018) within periods of wireless charge or fast charge only. I tracked it attentively. As soon as I sopped to use fast charge or wireless charge and moved to the regular one (5W) no decreases were observed for months, even years.

Back to iOS. On iOS 14.4 my iPhone 8 Plus showed 7-8 hours of work (quite active all-day social media activity and browsing) in wi-fi mode/5-6 hours of same work but in LTE-mode. No battery drain at night (when I slept and my iPhone was off wi-fi/LTE). No a single sign of interface slowdowns or any other issues.

After I updated to iOS 14.8 everything went horrific. I know about iOS indexing processes within 24 hours after you install a new iOS, but now it is not a thing to explain by, it's more than 52 hours after installation. No indexing at this moment.

Now here what "features" from Apple I have after iOS 14.4 > iOS 14.8:
4-5 hours of wi-fi activity (vs 7-8 on iOS 14.4) = -3 hours on average
3-4 hours of LTE activity (vs 5-6 on iOS 14.4) = -2 hours on average
Hello interface slowdowns!
Hello night battery drain to 4-5% of lying 6-8 hours on a table with everything off (wi-fi/LTE)!
Hello cellular data hangs (it shows that LTE is on but looks like no internet access; flight mode on/off only helps to fix it)!

I restarted iPhone multiple times, I closed all apps. Nothing helps(

I am really upset about it. Even if I had money to buy a new iPhone I wouldn't do it till they return me a TouchID option. I do not like FaceID, especially in a COVID19 world. I want my finger-identification back) at least as an option or choice between FaceID and TouchID.

So think twice before you upgrade your iPhone 8 Plus to iOS 14.8 (and 14.7.X as I've heard from others).

 

[BugeyeSTI]

My battery health is showing 81% on my 2017 X and I can honestly say my battery is compromised. If your battery is showing 80% I'd say yours is due for a replacement also. I have updated every time a new version is offered and some have worse battery management than others, that's a fact. 14.8 has been ok for me as far as battery is concerned but as I stated, my battery needs replacement and IMO blaming battery issues on the software when a battery is obviously not at peak performance is premature at best. If your sure it's software you can restore the phone and usually that straightens out most issues. I'd still consider replacing the battery though..

 

[Marinier]

If nothing changed except iOS 14.4 updated to 14.8 and right after that battery time shortened twice, you know) it is up to software, not to the battery health. I have 80% like more than a year and everything was great. Battery menu even does not offer me to chose between max performance vs other option, because iOS still thinks that battery performance is ok.
But thanks for advice. I’ve already talked to several guys who changed battery to a new one. They say it hasn’t changed the significant battery drain and shortened battery time that emerged right after upgrading to iOS 14.7 and later.

 

[BugeyeSTI]

If nothing changed except iOS 14.4 updated to 14.8 and right after that battery time shortened twice, you know) it is up to software, not to the battery health. I have 80% like more than a year and everything was great. Battery menu even does not offer me to chose between max performance vs other option, because iOS still thinks that battery performance is ok.
But thanks for advice. I’ve already talked to several guys who changed battery to a new one. They say it hasn’t changed the significant battery drain and shortened battery time that emerged right after upgrading to iOS 14.7 and later.

This is what I see in the battery health section. It doesn't give me any options to use max performance either it just says my battery isn't in great shape and performance might be effected..

As far as your battery draining, I'd try restoring the phone. It really straightens out a lot of issues, I'm not saying it will fix yours but it's worth a shot..

 

[Populus]

Hey, Marinier, hi.
I am sorry for your loss (of battery life).

I am on 14.4.2 and reading your post really discourages me from updating my iPhone. But I am afraid of Pegassus and other vulnerabilities that were patched in the past and the ones that will come in the future.

I was waiting for this iOS 14.8 thinking it would be a good thing, solving the issues of iOS 14.7.1, but apparently it’s even worse?

So I really don’t know what to do, I think I should update because iOS 15 will be even worse (performance and battery wise) for our iPhone 8. Is staying on 14.4.2 a bit risky and insecure? I don’t know, I’m not a cyber security expert, although I won’t miss any new features from iOS 14.5 or 14.6, I’m happy with my phone as it is right now.

What would you do, dear forum? Am I missing on important security updates staying on iOS 14.4.2?

By the way @Marinier if you don’t mind me giving you an advice, if you want more people participating on the poll and having more clear results, I would reduce the options to 3 or 4 at maximum. Having 7 answers would disperse too much the outcome and we cannot extract solid conclusions from it. I would focus the poll on iPhone 8 users, updating from iOS 14.4 or earlier (only iOS 14) to the latest 14.8. But it’s your poll so do what you think is appropriate. This was just an advice.

 

[Doctordafe]

RE: iPhone XR excessive battery drainage after iOS 14.8 update.

I had excessive battery drainage occur immediately after upgrading to iOS 14.8 (from iOS 14.7.1). I've noticed that my battery's peak performance has dropped 1% after each major iOS update, starting with 14.6. The battery's "peak performance" was listed as 96% while on 14.7.1 and now 95% immediately after the update to 14.8.

The battery drained from 93% charged to 12% charged within 2 hours, while the phone was not in use (screen off as well).

Already having an iPhone backup, while running 14.7.1, I decided to restore the phone to factory settings via a MacBookAir running Big Sur 11.6. The iOS update downloaded to the MBAir successfully, extracted the iPhone software, but after 10 minutes, I received "The iPhone could not be restored. An unknown error occurred (9)". I followed all of the Apple trouble shooting articles, including "If you see error 9, 4005, 4013, or 4014 when you restore your iOS device", but received the same "error 9" message. I removed security software, reset SMC, NVRAM, safe boot, and tested the issue in a new admin user account; same error. I also used the same cord that was used to back up the iPhone, proving the cable is good. I also tried all available ports on the MBAir.

I contacted AppleCare and they told me every available troubleshooting step had been performed and suggested I bring the iPhone to Apple or an Apple Authorized Service Provider. The AASP is booked and the closest Apple store is downtown and usually any downtown Apple store is caotic.

I'm wondering if iOS 14.8/iOS 15 has a issue with firmware, but do not know how to correct that.

Does anyone know how to manually, and fully, erase the firmware of the iPhone's hard drive without physically taking the iPhone apart?

Thank you for any advice!

 

[Populus]

RE: iPhone XR excessive battery drainage after iOS 14.8 update.

I had excessive battery drainage occur immediately after upgrading to iOS 14.8 (from iOS 14.7.1). I've noticed that my battery's peak performance has dropped 1% after each major iOS update, starting with 14.6. The battery's "peak performance" was listed as 96% while on 14.7.1 and now 95% immediately after the update to 14.8.

The battery drained from 93% charged to 12% charged within 2 hours, while the phone was not in use (screen off as well).

Already having an iPhone backup, while running 14.7.1, I decided to restore the phone to factory settings via a MacBookAir running Big Sur 11.6. The iOS update downloaded to the MBAir successfully, extracted the iPhone software, but after 10 minutes, I received "The iPhone could not be restored. An unknown error occurred (9)". I followed all of the Apple trouble shooting articles, including "If you see error 9, 4005, 4013, or 4014 when you restore your iOS device", but received the same "error 9" message. I removed security software, reset SMC, NVRAM, safe boot, and tested the issue in a new admin user account; same error. I also used the same cord that was used to back up the iPhone, proving the cable is good. I also tried all available ports on the MBAir.

I contacted AppleCare and they told me every available troubleshooting step had been performed and suggested I bring the iPhone to Apple or an Apple Authorized Service Provider. The AASP is booked and the closest Apple store is downtown and usually any downtown Apple store is caotic.

I'm wondering if iOS 14.8/iOS 15 has a issue with firmware, but do not know how to correct that.

Does anyone know how to manually, and fully, erase the firmware of the iPhone's hard drive without physically taking the iPhone apart?

Thank you for any advice!

You can go to https://ipsw.me/ and manually download iOS 14.7.1 for your device, put your iPhone in DFU mode, and restore it before Apple stops signing it, which will be sooner rather than later (my guess is today or tomorrow, Monday the latest). Good luck.

PS: did iOS 14.7.1 work well for you?

 

[MyPhone99]

I am in same boat as you, i had iphone xs max for year from 2018 to 2019 but i didnt like the narrower display and notch so i got a brand new ip 8 plus (red version) in 2019 and happily using it since then . my battery health was 95% before i updated to 14.7.1 but within a week after upgrading to 14.7.1 my battery health decreased from 95% to 90% ( it took close to 16 months for it to come from 100 to 95 but just a week for 95 - 90 ). so i didnt upgrade to 14.8 yet but looking at your post 14.8 seems to be much worst. Thank god i didnt made that mistake yet.

 

[MyPhone99]

I think the latest versions of IOS updates are definitely killing the battery health for older models. I think we should stop upgrading to latest IOS by the time we are done with 2 years of any iphone.

 

[Doctordafe]

You can go to https://ipsw.me/ and manually download iOS 14.7.1 for your device, put your iPhone in DFU mode, and restore it before Apple stops signing it, which will be sooner rather than later (my guess is today or tomorrow, Monday the latest). Good luck.

PS: did iOS 14.7.1 work well for you?

Interesting turn of events.

1. Downloaded .ipsw file for 14.7.1 - successful.
2. Put iPhone in DFU (Recovery mode) - successful.
3. Option+Restore - selected .ipsw file for 14.7.1 - successful.
4. 10 seconds later - error 9.

However, I still had a .ipsw file for iOS 13.7 (not assigned) and I immediately received an error about 13.7 being not assigned/blocked, but then my iPhone turned on. The iPhone still has iOS 14.8 and 95% battery capacity, but take a look at the picture showing 0% in the graph, but it's 71% charged.

So DFU mode alone didn't work, but obviously something got unblocked with the 'blocked' 13.7 .ipsw file. Super weird, and I'm glad I have a phone that will turn on.

I'll try to keep you updated if I figure out anything with the battery performance on 14.8.

Cheers and thank you for your suggestion!

EDIT: The first picture is while on iOS 14.8, the second picture is after I reverted back to iOS 14.7.1.

 

[SomeGuy1234]

Same issue here. iPhone 8 Plus. Never had issues with battery life or overall phone performance. Email (etc) is all manual updates only (no Push). Immediately following the 14.8 update, the battery drains about twice as quickly as before the update. It also takes about ~ twice as long to charge now. And apps no longer run smoothly, as they frequently pause and wait for the processor to "catch up".

It seems like some background process is churning endlessly, which could explain the battery and performance issues.

 

[Doctordafe]

I've had to reset the network settings after installing 14.6, 14.7, and 14.7.1, because my battery issues only happened while connected to cellular. A simple network reset fixed the cellular strength and the battery issue. 14.8 is different because this was the most drastic battery drain the phone has ever had and it happened connected to wifi with the screen off.

 

[Populus]

Maybe I should download 14.7.1 and install it while it is still being signed...

...Or just stay at 14.4.2

 

[TiggrToo]

I think the latest versions of IOS updates are definitely killing the battery health for older models. I think we should stop upgrading to latest IOS by the time we are done with 2 years of any iphone.

Terrible awful advice.

Security issues alone state that you should always patch until you can't.

Neither mine nor the wife's iPhone 7plus have issues and we're both on 14.8.

 

[nph]

Have 12 pro max and after taking 12.8 I loose 25% over night with NO activity. Freaking terrible.
If it wasn't for the security aspect I would have stayed on 14.4 for ever when I got almost 3 days out of my phone. Seriously considering the 13 due to the bigger battery.

 

[eastworm]

Same issue here. iPhone 8 Plus. Never had issues with battery life or overall phone performance. Email (etc) is all manual updates only (no Push). Immediately following the 14.8 update, the battery drains about twice as quickly as before the update. It also takes about ~ twice as long to charge now. And apps no longer run smoothly, as they frequently pause and wait for the processor to "catch up".

It seems like some background process is churning endlessly, which could explain the battery and performance issues.

May i know you update through OTA or u did a clean install?

I'm usually the guy who don't update my phone for small updates through OTAs and prefer clean install for major updates. I never enter DFU recovery mode and always follow this guide for clean install process.
https://wccftech.com/how-to/how-to-clean-install-ios-14-and-ipados-14-final-version/

I came from iOS12 on my iPhone 8 Plus straight to 14.4.2 > 14.7.1 > 14.8
If any of you has 14.4.2 works on your phone, 14.7.1 will be so much better, trust me.

14.8 so far with 2 days of usage, buttery smooth, very responsive. Battery wise, maybe slightly worse than 14.7.1, or maybe it's just placebo after reading so many negative posts, but i think the difference is negligible. App wise, there is 1 photo app seems like broken after update, and 1 banking app stuck at launch screen for only once, then i really didn't face any other problems yet, finger crossed. Then again, I'm not sure if it's the app issue or 14.8 because i don't use that 2 apps often in 14.7.1, i encountered the issue when i installing back my app after clean install.

If not because of me worrying the 2 major exploits before 14.8 patch, i would definitely stays on 14.7.1 until iOS15 is stable and proven to be working fine on 8 Plus. It's really time consuming for clean install, especially when i thought 14.7.1 will be the last major update and i just did it a month ago. I plan to use this phone for at least 1 more year so security>battery or other concern.

TLDR: Always clean install for best experience. Update to 14.7.1 for stability since it was community beta tested. Or update to 14.8 if security is your priority.

 

[Robmcsp]

Interesting turn of events.

1. Downloaded .ipsw file for 14.7.1 - successful.
2. Put iPhone in DFU (Recovery mode) - successful.
3. Option+Restore - selected .ipsw file for 14.7.1 - successful.
4. 10 seconds later - error 9.

However, I still had a .ipsw file for iOS 13.7 (not assigned) and I immediately received an error about 13.7 being not assigned/blocked, but then my iPhone turned on. The iPhone still has iOS 14.8 and 95% battery capacity, but take a look at the picture showing 0% in the graph, but it's 71% charged.

So DFU mode alone didn't work, but obviously something got unblocked with the 'blocked' 13.7 .ipsw file. Super weird, and I'm glad I have a phone that will turn on.

I'll try to keep you updated if I figure out anything with the battery performance on 14.8.

Cheers and thank you for your suggestion!

You might have tried this already, but make sure you have as many free GB on your HDD/SSD as what your iPhone has, or at least try freeing as many GB as yourbackup weights.

I was on the same trouble this last week trying to downgrade and this was what solved the problem for me.

XS working without an issue now on 14.7.1, OTA updates are locked by tvOS beta profile and let’s see how it goes with iOS 15…

 

[Doctordafe]

You might have tried this already, but make sure you have as many free GB on your HDD/SSD as what your iPhone has, or at least try freeing as many GB as yourbackup weights.

I was on the same trouble this last week trying to downgrade and this was what solved the problem for me.

XS working without an issue now on 14.7.1, OTA updates are locked by tvOS beta profile and let’s see how it goes with iOS 15…

I couldn't live with the battery drain using 14.8, so I did end up restoring 14.7.1 using standard recovery (not DFU). I'll keep track of this post to see if the next update after 14.8 solves the battery issues because I do miss the look of 14.8.

Thank you for the advise and support. Cheers!

 

[Doctordafe]

Maybe I should download 14.7.1 and install it while it is still being signed...

...Or just stay at 14.4.2

Yes, I think iOS 14.7.1 would be a good idea while it's still assigned, versus 14.8, if you're going to update.

I did not notice a difference in battery drain between 14.4 and 14.7.1, although I have had to reset the network settings after each update, otherwise the battery will drain fast.

Every post I've seen from people having battery drain issues since 14.4, where reseting the network settings did not fix it, have continued to have battery issues with every update, which leans towards the possibility of an actually hardware issue with the battery.

I'm hoping Apple will release a 14.8.1 update soon, that doesn't zap battery performance.

 

[nph]

Give it 24 hours after upgrading to 14.8 then do a hard reset. That worked for me, back to 2 days battery life (barely)

 

[humpbacktwale]

4-5% of drain overnight is extremely mild, and should be the expected amount even if wifi/LTE are off. In all likelihood your battery wasn't reporting correct statistics before, and after this update now is.

 

[!!!]

I've been experiencing absolutely awful battery drain on my iPhone 8 after updating to 14.8. It's very erratic, sometimes during the day my battery will drain at a normal rate. Other times I'm on it for maybe 5 minutes and I've dropped 10%. Same thing with just having it off, sometimes it won't drain at all and other times it will take a nose dive.

I used to be able to have about 10-20% left by the end of the day. Nowadays I hit that at noon. I also have Apple's "Smart Battery Case" which I only sometimes use when I'm going out due to how heavy it is. If I do use it that day, I've noticed I'll run through the entire battery case and start eating away at my phones battery. This, along with viewing my phone's battery info in coconutBattery lead me to believe it has nothing to do with the actual health of my battery. It very much seems like a rouge process that won't stop running in the background. If it were a real computer I'd be able to see which processes are running via Activity Monitor or Task Manager. Alas, Apple has decided we should suffer instead of have what is clearly a dangerous tool.

I've even reset and restored my phone from a backup. No change. Today my battery was doing fine in the morning but it has since degraded back to its old ways. I used my phone for about 5 minutes and it dropped 10%. I'm not using any apps or doing anything that would use more power than I have in the past 3 years with this phone. I've even used it with low power mode on, airplane mode, and at the lowest brightness I can take some days and it's still abysmal.

 

[JerryBee]

Battery life is DREADFUL after update to 14.8.1. I'm constantly charging it. Sometimes it doesn't even fully charge.

My guess is that Apple wants 8plus users to upgrade to a newer/more expensive phone. Why else would they screw up a perfectly good phone? The 8+ is the best iPhone I've ever had and I don't see any reason to upgrade.

 

[Populus]

Battery life is DREADFUL after update to 14.8.1. I'm constantly charging it. Sometimes it doesn't even fully charge.

My guess is that Apple wants 8plus users to upgrade to a newer/more expensive phone. Why else would they screw up a perfectly good phone? The 8+ is the best iPhone I've ever had and I don't see any reason to upgrade.

Maybe your battery needs a replacement? I say this because I’ve stayed at 14.4.2 for a long time, and sometimes I notice a battery life decrease. And yeah, mine is at 82% of health, and it definitely needs a replacement.