Battery problem after update to IOS 9.3.1

Download latest ios 9.3.1 and do a clean restore and of course set a backup before that, I 99% sure that will help you.

I had issues with severe battery drain - it started 5-6 days after 9.3.1. IMO I don’t think this is tied directly to that release. I did a lot of investigation on my own - using Xcode/Instruments to monitor the iPhone to discover what may be causing the battery drain. I also visited and talked to Apple Support. I hope the following helps anyone with a severe battery drain — these are not the standard recommendations that get posted to reduce battery drain.

• I found a system task/daemon was consuming an inordinate amount of CPU time. I know there are some system tasks that do run when the phone is plugged in, locked, and connected to wifi - this task was not one of those. The task that was creating the issue: indentityservices. This task is tied to the Messages queue.
• In my case iOS itself was recording problems with this task. Look at your diagnostics log. If you see an entry that looks similar to this: Exc_Resource_identityservices . . . - you likely have the same issue as I did.
• In talking to Apple - they recommended I restore the device as new.
• I started setting it up as new thru iTunes - I got an “Activate iPhone” screen stating the iPhone had been previously activated - under a different Apple ID. It was my iPhone from day one - and was acquired new in an Apple store at launch day. I never used another ID. I called Apple and I sent my proof-of-purchase to a security team who unlocked my iPhone in 42 hours.
• I set up the device as new - loading all apps from the App store (not from a backup) and re-created all the settings.
• I’ve tested the my iPhone now for almost two days - no more heavy battery drain. In fact, battery life is now phenomenal.

Just as background - my problem was first noticed on my Watch - then we (Apple genius person) saw the IPhone draining too. This “identity services” task also created issues on another iPhone/watch combo on the same ID - and on our Mac and laptop. Really very unusual. My personal opinion is the ‘foreign’ Apple ID that was attached to my iPhone was the source of the identityservices task to go wild. That task runs on the Watch, iOS devices, and OS X if you have Messages tuned on. Again, that’s just conjecture on my part. How it got attached to my iPhone - no idea. But, as soon as Apple support saw that ID they immediately transferred me to a Tier III person. And, should you do some searching - you’ll find that other people have had this particular activation issue when setting up their phone as new. It seems a number of them was attached to a yahoo email address.

Before I took the nuclear option, I tried ‘reset all settings’ - that worked for about a day. If you choose to a DFU restore - I’d try some of the standard things people recommend. Only caution if you decide to try this - make sure you have your proof-of-purchase for your iPhone in case you run into an activation problem.

In any event, I’m getting great battery life. Just re-paired my Watch - hope that will no longer have battery drain. If my battery drain on my iPhone gets bad again - I'll post a note.

Wow, that exactly describes my symptoms. So I thought I would inspect the logs this morning. But now I find my phone is totally bricked. Black screen, nothing will wake it. Great, thanks Apple. An out of warranty phone screwed by you guys at my expense.

I have a 6s Plus and soon after the 9.3.1 update I noticed a huge change to my battery life. I am a very light user of an iPhone and prior to the update i was getting over three days before a charge was needed. I would normally have it switched on for about 12 hours each day and turned off over night. Now I am lucky to last a day and a half now. Initially with Apple Support they asked to to try the following:

1. Reset with Power and Home buttons (no change)

2. Erase All Settings (no change)

3. Erase All Content and Settings setup as a new iPhone (no change)

This being the case I decided to use iTunes and restore downloading the iOS 9.31 and installing again but this time for testing I did not install any other additional apps, I just had the apps that came with the IOS nothing else. So for six days I was only using my iPhone for email, messages and phone calls and this made very little difference to the battery life and left me fed up.

Soon after this I decided to book a Genius Bar appt at Liverpool for last Saturday so I went along and the person who looked at my issue did some diagnosis on the battery and he could clearly see that the battery was fine and not a hardware issue but on a number of occasions I did say that my issue happened soon after i updated to 9.3.1 so surely this was a software issue and I was informed that they could not revert back to the previous IOS which left me fuming and stuck. The Apple guy said if I had to charge my iPhone twice day then they would say that I had an issue and wasn't to bothered about that I was a light user and the change from having 3 days to now having 1.5 days. I suppose if I was a normal user I would be charging it more often!!! Since then I have put my apps back on and using it as before. Today I noticed when I got back from work that my battery went down exactly 50% and I have been mad busy with no time to use when i had a break and just one phone call. I thought Apple made the hardware and software and also supported them both too but I feel that I have to wait for the next iOS update to see if that improves things but i'm guessing my battery might get used to being pretty useless if I carry on using as is now!!!

I also have an Apple Watch connected to my phone but the battery still lasts 3 days like my iPhone did. How did you find the identity services as I would like to l;look into this?

Thanks in advance

Mine has been working now since Saturday when I set up the iPhone as new - the only difference is I used DFU mode to get there. I did this specifically at the Apple advisor's recommendation. https://support.apple.com/en-us/HT201263

I chose Restore - NOT update. I set up the phone as new and went thru the activation process. I did not restore from a backup - I downloaded all my apps and re-set all my settings. If you choose to go this route - one suggestion - make sure you have proof-of-purchase (invoice with your name, store info and phone info including IMEI) ready in the event you run into the problem I did - see prior post.

It's working great now.

I downloaded xCode and used instruments to monitor activity.

Same darn problem! Since iOS 9.3.1, my battery drains rapidly & the phone overheats. Today with 26 minutes of screen time Safari had used 60% of my battery. This is not normal at all. Why isn't there a bloody fix for this? I have resisted this upgrade on my iPad. I'm currently looking for a Samsung. I've had it with Apple.

I was dropping down to 10% off battery left in about 4 hours of minimal usage. Had been going about 10 hours and having about 65% left. Since I always go for the simplest and fast fix and after reading all the comments here, I tried a simple version of what "robnbill" posted. I went to the report https://support.apple.com/en-us/HR201263 and connected my 6s to my computer and opened iTunes and followed the instructions and chose update. Waited while iTunes reinstalled 9.3.1. Plugged in my 6s to it's charger over night and yesterday went 10 hours with my minimal use and 81% left on my battery. Even when i was shut down, before the reinstall i was losing battery storage. Today, with only a few texts and 2 short phone calls and maybe 5 minutes internet access and about 4 hours on standby, I'm still at 99%. 🙂 I hope it's a permanent change. i'm wondering if the version I first downloaded had a glitch?

St8dawg said

I AM NOW THINKING ABOUT GOING BACK TO ANDROID. I changed to iphone to get away from things not working right.

That's exactly how I feel right now. I went through something like 5 androids (3 LG, 2 Samsung) in the last 4 years and it's always ended up with battery problems, performace problems, having to replace the dang phone because it's no longer supported ( ....? lol) less than a year after purchase.

So I finally cracked and shelled out my hundreds of dollars for an iPhone. At first I was really impressed with how ios performs. Until very recently. Now I have this stupid phone that drains 60% on IDLE in 3 hours. Half the time I can't even get it to charge - but there's no looseness or visible damage to the port or the cable. I have to turn the phone off then on again before plugging it in and its now at about a 50% reliability for that working.

I am heading to the store to see what they can do but I have a feeling I am just going to have to get a replacement phone, which means what, being without a phone until a new one arrives?

Scary stuff when you have a child with multiple disabilities and are reliant on your phone to keep in touch with the school in case of emergency.

So now I'm really< REALLY UNIMPRESSED with the HUGE amount of money I spent on a phone that didn't even last 3 months - My worst Android at least lasted 7 + months!

Researching this problem it seems that there are ALWAYS problems with battery drain after an update. Perhaps apps aren't ready for updates and something goes screwy? I really don't know, I'm not a tech chick . However, I am beginning to understand why iPhone sales are declining so significantly.

I'm iphone 5s 64 gb user and i feel the same battery problem draining so fast after i updated to ios 9.3.1

So you used the option that just re-installs the iOS firmware and doesn't mess with your data. Not knowing if any of my existing user data might have been contributing to the issue - I did the restore and set it up as virgin. A little more time consuming.

Quick question - did you get the "Activate iPhone" screen when you updated???

I did this last Saturday and I have been getting phenomenal battery life - e.g., at 36% battery - 38 hours standby and 7 hours usage. I'm sure the system task I pointed out is what was causing the battery drain - it's running minimally now. That identityservices task is also on our other iOS, OS X and Watches. It was also creating the same sort of battery drain on our other iPhone and an OS X Mac and an OS X MacBook. Very odd - clearly a symbiotic relationship. I think it was working on the same message queue - but the fault was on my iPhone. I hope the great battery life continues.

Tried the restore as per robnbill instructions setting up as a new iPhone via DFU mode and installing apps manually shortly after your reply with my fingers crossed but battery does not seem any different at all but I was not prompted to activate my iPhone. Have I missed something out? It lasted just over a day and an half again with very little use. I only purchased the phone two months ago brand new and for the first five or six weeks it was a dream until 9.3.1 came along. Where can I find this identity services task, I have checked out Privacy > Diagnostic & Usage > Diagnostic & Usage Data but I can't spot it but maybe I'm looking in the wrong part? Any help appreciated as I'm starting to feel that I made a wrong move with this phone although I know it's not the phone it was IOS 9.3 1!!!

Sorry it doesn't appear to have worked in your case. From what you wrote - it seems as if you did not restore anything from a backup.

The identityservices task is part of IOS. In order to see task activity you need to download Xcode and use the Instruments (activity monitor option) feature to see what task is using CPU cycles while locked. You have to plug your iPhone into the Mac in order to do that.

Assuming you have diagnostics turned on in the iPhone - you can pull up the reports (they are in alpha order). Look for a task that starts with Exc_IdentityServicesd - - - - -. Look at that report - it will address CPU time and say it is not a crash report. It will also point to the thread causing the excessive CPU time. Mine always pointed to a thread that was dealing with messages.

One other thing I noticed - when I was still having battery drain - is the usage and standby times were very close together, Unless you you are using the phone all the time - the usage time should be much lower. In my case and usage it's ~1 to 5. Right now: 8 hours usage and 40 hours standby with 33% battery. If they are relatively close together - something is using a lot of CPU - and the only way to find out is to Instrument your iPhone - otherwise it's just a guess.

As to the "Activate iPhone" screen - that was unusual in my case - since some foreign Apple ID showed up - Apple took care of that. And, yes, I bought the phone new directly at an Apple store - it made no sense and Apple agreed.

Since your phone is less than a year old - you still have warranty support - call Apple and tell them what's happening. Follow their suggestions. While these forums sometimes help - we are only users trying different things which may not work in every case - I guess you could just have a defective battery.

Same here, so boring, as in super boring having to troubleshoot almost every other ''update'', browse through forums, yadda, yadda, yadda… it's getting old real quick - & THAT is a cost i definitely DIDN'T sign up to pay !!

& this is with MINIMAL useage : couple of hours in standby uses ginormous amounts of battery.

Plain ridiculous.

No I didn't get the "activate iPhone" Screen. Just did what the report said to do. Right now I'm at 77% battery, 2hr, 10 min usage and 10hr, 42 min stand by. Couldn't believe how easy it was to fix. Took about 23 minutes and that was mostly download time. Again, hope it lasts. Thanks for your input.

@tkjwhite - I want to try what you did but from the link you posted I get page not found. Can you report the link.

Many thanks