iPhone 5S getting incredibly hot and high battery usage after iOS 8 update

gets so hot that holding it becomes a problem

Alright so let me just first say that my experiment was met with immediate failure. The second my phone last night hit 99%, it was literally dropping 1% per maybe 3-7 minutes while I was texting my friend... This was ridiculous, at first I thought maybe it will last me the whole day.... but then it hit 88% before 12, and I said, nah, screw that, so I watched videos instead on YouTube to drain it down to around 60% after like 3 videos? And I just checked how YouTube used 16% roughly and Home n Lock Screen still used more than YouTube by several %s, and I am wondering... how does my home and lock screen burn through more battery than YouTube!?!?! But, my battery hasnt gotten better at all, and if at all, maybe even worse than before draining it to 0%...

After I plugged it in I woke up at 6:30 and then I was out until now, 8:21PM, and it has 40% left. You may think, hey, its not bad.... but I BARELY touched my phone. Once I was at school about 9am, I was experiencing the same type of quick-drain after my phone hit 99% and it was going down roughly as fast as it was last night. So I would advise people NOT to drain your phone, if my results could be replicated, I'd prefer if no one else did since it seems it got a bit worse..

I guess for now, we can only hope for 8.0.1. When will Apple release it? Or when has Apple usually in the past released a X.0.1 version??

In other news, Lee, I forgot to clear something up with you. Out of the problems in the title, I only experience the battery drain (and also home and lock screen taking majority of battery) but no heating of my phone. My phone was only very heated when I was upgrading OTA when the iOS came out (literally when it first came out 1:00PM EST Sept 17) and after the install, and during it, my phone was heated up which is understandable considering the size and length of the upgrade. Anyway, other than that, I have not experienced any heat on my phone! My phone is in an Otterbox Defender case too, so I would assume if anything, mine would heat up before anyone else's without a case... But yeah...

After upgrading my 5S to iOS8 I have very poor battery life while listening to podcasts. I only get about 2 hours of playback before the battery is drained.

Phone is also very hot.

Standby time is fine with no problem at all.

I have tried to reset all settings, setup as new phone. Turned off all background tasks, Handoff, podcast download and so on.

With iOS7 I was able to listen to podcasts almost all day without any problems.

Its kind of suck as I used to be able to listen to podcast on my daily commute.

Continuing with my CPU tests using app Lirum Info Lite, without changing anything and doing the same CPU usage visualizer but this time using the cellular network instead of Wi-Fi from my work, during the whole day my iPhone showed a lower usage for both CPUs running at an average within a range of 2 to 4% of CPU usage each core, despite having some spikes going to 7-15% level or even higher ones for one second to 40% level.

Other change I noticed is that now both cores run more in parallel than going both in the opposite directions (up or down in CPU usage), but continues to have seconds when one core goes to 0% while the other keeps making the task for the CPU. This doesn´t mean that the cycles of 60% usage have gone, they return in action after several minutes and return to low 2-4% and minutes later again to the 50-60% usage level, and so on. This happens while not using any app in addition to the Lirum Info app used for the test.

The unique software that sound strange about its use of battery remains the Home/Lock Screen, with 15% for the last 24hrs. In my case the other apps I have used in the past 5 days show:

Mail: 23%

Lirum Info Lite: 11%

Safari: 10%

Remote: 8%

Whatsapp: 6%

Settings: 4%

Bloomberg: 4%

Other apps: 3% and less each one

So now I feel the battery is draining much slower than just after the upgrade to iOS 8. But I still find very non understandable these cycles of 50-60% CPU usage. I have Mail updated every hour not with Push. So not considering Mail and Lirum Info Lite, Home/Lock Screen seems to be one cause of the problem do to the fact that I haven´t used Notification Center or Control Panel, but may be is due to the use of the Touch ID to unlock the screen?

I haven´t drilled down the cpu usage to see % usage by Process Name. I haven´t discovered an app for this info yet. But not planning to loose more time on this issue, Apple employees are getting a salary to do the debug task, so let them do the job.

Mine behaving strange. I haven't used "rove" app for 2 days. I also diabled background activity for all apps. But in usage shows that "rove" has used %7 of battery in background activity. In the last 24 hours the app used %35 of the battery. I assume that this battery usage is showing wrong!

with ios 8, my iphone now is a little slow. When I exit safari and entering it (not closing the app) the content take 1 sec to show. With ios 7.1.2 even with 16 tabs there wasn't a problem. And when someone calls, when I "slide to answer" it takes 2 sec to respond and answering the phone. Why?!! Please I don't want ios 8. ios 7.1.2 was much better. Apple please I want to go back to 7.1.2

Well, to keep a positive spin to it - "Apple please hurry up and get 8.0.1 out!"...

It is disappointing that this happens, but I guess it's not easy to get 100% bugs/eventualities sorted prior to release.

I have friends who don't have any issues with their installation of iOS8 so... luck of the draw it looks like.

:-(

I had an exchange automatic reply problem. It always said "Loading..."; when I deleted this exchange mailbox my phone went back to normal operation.

Normal battery life no more heating.

Battery Doctor App helps me this time. Battery kept draining quickly until I loaded the app which I had since Ios7.. and followed other tips of turning off such stuff etc...

Its some kind of error reporting bug in the battery percentage? I had it at 1 percent for 2 days after installing ios8..then it finally shut off... however battery doc app repaired that I guess. So far, it remains at 100 percent on standby unplugged for 12 hours now.. hope thats not a error reporting either. I read where I needed to drain the battery completely before recharging again - when it hits 100 percent, let it 'charge over for 2 more hours' then unplug it.. this calibrates the battery as well.. I guess.

oh its a iphone 5s

I have observed its all because of Apps, (as Most of the apps are not optimised for iOS 8)
And Because of WiFi Module Configuration Problem, As iPhone 6 has new module of WIFI where as previous iPhone have the old Module and the OS is configured according to the Latest module of iPhone 6 and iPhone 6+...!
So the Problem is not OS But the Apps..!
Heres a Trick that will not solve the problem but will help you guys alot..!

AbdullahAkbar, what do you mean when you say 'optimised for iOS 8'? Do you mean updated using the new version of Xcode or something else?

Today it seems iOS 8 is going normal on my 5S, no excesive battery drain nor iPhone getting hot. Anyway, it's obvious that a high CPU usage leads to high power and heat being generated on the A7 chip and this only means fast battery drain in the end. Luckily it seems like the initial period of high cpu activity after the upgrade to iOS 8 has ended. May be iOS was programmed with some set of initial processes to gather your info, indexing databases, and may be auto setting parameters of the system according the users behavior, apps running. Just guessing, iOS experts should explain the real thing.

With more than a million apps in the App Store, is not possible to have iOS 8 compatible with all of them at once. So many of you may have been experiencing issues with one or more of your apps. In benefit to the better iOS we have upgraded to, we should be patient with developers to upgrade their apps to be iOS compatible in every aspect, and if you can't wait for that, try to find a replacement app. Obviously, this thought don't include the most common or popular apps that should be updated in App Store right after iOS 8 launched to have a smooth and free of bugs user experience with your apps and iOS.

The best iOS user experience called "It just works" is what all Apple user is expecting after all. So I would be happy to hear what says the Senior Vice President of Software Engineering at Apple Headquarters, Mr. Craig Federighi, about the strange behavior we all suffered with our iPhone 5S after upgrading to Apple's new iOS 8.

In retrospect, and with a few days to cool off, the possibility of this being due to apps not fully updated to iOS8 seems most plausible.

Indeed, the updating of apps seems to be happening at a frenzied pace.

Here's hoping...

Well, 8.0.1 is due anyway for the yet unreleased features of Continuity etc I suppose...

Hey Guys.. Me too is having the same issue.. did all the stuff to resolve the issue but that didn't helped. Talked to apple care like almost 20 times, even visited Apple Store twice but none of them worked. Got a call from Apple Representative today that i will be exclusively getting the update to fix the bug within 72 hours. Fingers crossed! That means update or patch will be rolled out by the end of this month... CHEERS! 🙂