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Regarding recalibration of the battery, my SE was on 67% last night when I went to bed.
This morning at 7am when I woke up it had dropped to 1% on the gauge, so I decided to run it down until it turned off before recharging and see if that helped.
It's now just after 11 o'clock here, 4 hours after waking up, and the battery is still showing 1% and not showing any signs or warnings of low power.
I've been playing games, checking emails etc. but it still hasn't run down.

Definitely needs recalibrating ;)

Cheers :)

Hugh
 
Yes your contacts, email, notes, passwords and messages are backed up to iCloud. Whatsapp has its own cloud service. You can restore your chats by typing in your phone number. Manually backup your photos.

Restore using iTunes. Click on restore, not update! After the restore has completed, on your phone, it'll ask to sign into iCloud. Sign in. After that it'll ask to restore from an iTunes backup, restore from your iCloud backup or set up as new. Select set up as new. Don't worry. Your contacts, messages, emails etc will be back on your phone in a few minutes. You won't have any apps though.

Perfect..! Exactly what I needed to know... thank you so much!
 
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Perfect..! Exactly what I needed to know... thank you so much!

No problem. Remember, messages won't back up to iCloud until the phone is connected to WiFi and charging, so check if everything is backed up before restoring. Good luck and let us know how it goes!
 
Perfect..! Exactly what I needed to know... thank you so much!

Already did that (clean install via iTunes and setting device as new) 3 times plus two battery “recalibrations”, after updating to iOS 12.0.1 I noticed a “tiny bit” of an improvement, but maybe I was under some sort of placebo effect. Battery is 25% worse than before on my iPhone 6s 64GB (battery health 98% - second battery)
 
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Already did that (clean install via iTunes and setting device as new) 3 times plus two battery “recalibrations”, after updating to iOS 12.0.1 I noticed a “tiny bit” of an improvement, but maybe I was under some sort of placebo effect. Battery is 25% worse than before on my iPhone 6s 64GB (battery health 98% - second battery)

Thanks man! you saved me a huge hassle.. I was getting ready to do it this weekend but now I wont bother..!

I've borrowed my friends SE which he has allowed me to restore an old backup I have and its running 9.3.5. I'm going to charge both mine and he's to 100% and put them on air-plane mode with no use at all to see which can outdo the other. Both batteries are around the same health and will have exactly the same applications. It should give us an insight into power usage when completely idle (no ability to collect or download or send data).
 
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Already did that (clean install via iTunes and setting device as new) 3 times plus two battery “recalibrations”, after updating to iOS 12.0.1 I noticed a “tiny bit” of an improvement, but maybe I was under some sort of placebo effect. Battery is 25% worse than before on my iPhone 6s 64GB (battery health 98% - second battery)

What are you comparing iOS 12 to? If it's iOS 10, then it probably is using 25% more power. I know because I clean installed iOS 11 on my 7 Plus last year, and noticed a 20% reduction in battery runtime. That's just how the OS was.

If you're comparing it with iOS 11, then maybe it can't be a proper clean install. Maybe you're unknowingly restoring from a backup from iTunes or iCloud. Or maybe you're using an app that just doesn't work well with iOS 12. I've done plenty of clean restores. I always clean Restore when an update comes out. I never do OTA updates. Been doing that since iOS 3. I never had battery drain issues.
 
What are you comparing iOS 12 to? If it's iOS 10, then it probably is using 25% more power. I know because I clean installed iOS 11 on my 7 Plus last year, and noticed a 20% reduction in battery runtime. That's just how the OS was.

If you're comparing it with iOS 11, then maybe it can't be a proper clean install. Maybe you're unknowingly restoring from a backup from iTunes or iCloud. Or maybe you're using an app that just doesn't work well with iOS 12. I've done plenty of clean restores. I always clean Restore when an update comes out. I never do OTA updates. Been doing that since iOS 3. I never had battery drain issues.

I'm comparing it to iOS 11. I perfectly know how to do a restoration using the latest available firmware through iTunes and then setting device "AS NEW" (DFU MODE). I used to have those "normal battery issues the first 24/48 hours in the past due to the indexing of the new code", but in this specific case I sense there's a bit more going on with iOS 12. Every major iOS update I always do the same procedure and it's only been in this specific one where I'm having those problems.
 
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Well after having a good result when draining my battery and then charging using an Apple charger, it only lasted until the next charge :-(
I thought is could have been due to my speaker dock which also charges the phone when docked, so have not used that, but it hasn't seemed to have made any difference.
Time to officially log it with Apple.
 
this is how my battery life is with iOS 12 Beta 3, what you think about - was a mixture of WIFI 2H and a bit LTE, I had 30% Battery left at this time shown here on the graph
 

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Battery life on ios 12 in general is pretty bad. I feel like battery drops by 2% very fast. I am seeing this behavior on mi iphone x (battery health 98%) and my ipad pro 10.5. Exactly same thing on both devices and if don’t turn on airplane mode during the night, battery drains around 10% without any reason.
 
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Battery life on ios 12 in general is pretty bad. I feel like battery drops by 2% very fast. I am seeing this behavior on mi iphone x (battery health 98%) and my ipad pro 10.5. Exactly same thing on both devices and if don’t turn on airplane mode during the night, battery drains around 10% without any reason.

I have found out complete airplane mode one and turning iCloud off and the battery life is really good. Even turning iCloud off it’s a big difference and I have made a complete new install with new iCloud address because I thought something is ****ed up with the old iCloud account - but it wasn’t
 
After conducting the 9.3.5 test with exactly the same options apps and usages there is definitely less battery life between the two devices. They drain almost at the same rate (standby only) when not touched however the minute you start firing applications on both devices at the same time both in Airplane mode or in Wi-Fi there is a delta increase of approx 1.3% for every 1%. So while the 9.3.5 device would drop 1% the 12.0 device would drop 1.3% or so. I calculated it based on the overall delta. Taking it all into account you would lose .3% of the battery per 1% quicker. This was solely my experience. It is certainly not too bad considering you get a 'few' extra advantages from running 12. Battery condition was almost identical on both devices. In all cases I really don't think it is too bad (providing most users are getting the similar results).
 
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My battery life did not deteriorate going from 11.4.1 to 12.0 but after installing 12.0.1 it’s gone downhill fast. The battery meter drops in front of my eyes as I use it. Based on screen time I get about 2 hours usage before it’s drained. On the plus side it’s training me to use my phone a lot less (maybe that’s part of the goal of ios12!). I’m switching to my backup phone - iPhone SE with 11.3. Battery life is at least twice as long with the same apps and usage. Tired of doing this ‘install as new’ rigamarole every time. Takes a good half day to get everything resintalled and reconfigured with the correct login IDs
 
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My battery life did not deteriorate going from 11.4.1 to 12.0 but after installing 12.0.1 it’s gone downhill fast. The battery meter drops in front of my eyes as I use it. Based on screen time I get about 2 hours usage before it’s drained. On the plus side it’s training me to use my phone a lot less (maybe that’s part of the goal of ios12!). I’m switching to my backup phone - iPhone SE with 11.3. Battery life is at least twice as long with the same apps and usage. Tired of doing this ‘install as new’ rigamarole every time. Takes a good half day to get everything resintalled and reconfigured with the correct login IDs
I have exactly same experience
 
My battery life did not deteriorate going from 11.4.1 to 12.0 but after installing 12.0.1 it’s gone downhill fast. The battery meter drops in front of my eyes as I use it. Based on screen time I get about 2 hours usage before it’s drained. On the plus side it’s training me to use my phone a lot less (maybe that’s part of the goal of ios12!). I’m switching to my backup phone - iPhone SE with 11.3. Battery life is at least twice as long with the same apps and usage. Tired of doing this ‘install as new’ rigamarole every time. Takes a good half day to get everything resintalled and reconfigured with the correct login IDs

I have exactly same experience


I had the exact same issue and a battery replacement seemed to have done the trick. Battery health was at 97% and was only 5 months since I had it replaced.
Symptoms include sudden drops in percentages while watching videos and inexplicable drain just while having the screen ON. Neither the DFU restore nor the battery calibration worked. My settings were very battery conservative with BAR off and Location Services only set to While Using to some of them with "Never" to most everything.

Finally took it to the Genius Bar and have them run the diagnostics. After noticing some weird spikes in the usage, they offered to replace the battery.
 
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After my 6s with 12.0.1 shutdown with 30% battery left I had enough. Switched to my backup SE running the widely panned iOS 11.3. Wow I’ve been using it all morning (same apps and usage pattern) and it’s still at 88% by noon. And it even has background app refresh enabled and gmail set to fetch periodically.
 
After my 6s with 12.0.1 shutdown with 30% battery left I had enough. Switched to my backup SE running the widely panned iOS 11.3. Wow I’ve been using it all morning (same apps and usage pattern) and it’s still at 88% by noon. And it even has background app refresh enabled and gmail set to fetch periodically.
Wish I would have switched back to 11.3 when it was still possible. I find it funny people hated 11 so much when some of us had no problems. My main concern is getting security updates, but most people don’t seem to care much about that. Hell, some are still on iOS 9. After using it more, I would gladly trade the features of 12 to get the battery life of 11.
 
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I had the exact same issue and a battery replacement seemed to have done the trick. Battery health was at 97% and was only 5 months since I had it replaced.
Symptoms include sudden drops in percentages while watching videos and inexplicable drain just while having the screen ON. Neither the DFU restore nor the battery calibration worked. My settings were very battery conservative with BAR off and Location Services only set to While Using to some of them with "Never" to most everything.

Finally took it to the Genius Bar and have them run the diagnostics. After noticing some weird spikes in the usage, they offered to replace the battery.

The Genius Bar replaced my 10 month old SE due to rapid battery depletion and shutdowns after installing iOS 12. Genius Bar diagnostics noted lots of spikes too.
 
The Genius Bar replaced my 10 month old SE due to rapid battery depletion and shutdowns after installing iOS 12. Genius Bar diagnostics noted lots of spikes too.

I’ll make an appointment at the Genius Bar. The status on this 5 month old battery shows 96% but there’s also a message below that says: “This iPhone has experienced an unexpected shutdown because the battery was unable to deliver the necessary peak power. Performance management has been applied to help prevent this from happening again”. I guess that means it’s applying throttling.
 
My new SE is only 6 months old. Battery at 100% capacity is bad on 12.1. I wish I still had 12 on my SE when battery was as good as on 11.3.
 
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I’ll make an appointment at the Genius Bar. The status on this 5 month old battery shows 96% but there’s also a message below that says: “This iPhone has experienced an unexpected shutdown because the battery was unable to deliver the necessary peak power. Performance management has been applied to help prevent this from happening again”. I guess that means it’s applying throttling.

That's correct, my original SE said the same with 100% health and 90 cycles. I didn't re enable full power mode but left it in throttle mode to show the Genuis Bar hard evidence of the event.
 
I’m running the latest iOS on an Xs Max and things are pretty good. It uses slightly more than when I ran the beta and the final on my 6S Plus so i’m Happy with that.

You shouldn’t have to but go back in and check all your settings, especially screen bright ess, to make sure it hasn’t changed them. So,e of mine did get changed unknowingly when the updates were made.

As a matter of fact I just found this morning the later IOS12 had changed the "True Tone" from off to on.Also a couple of notification settings had changed.
 
Uhm, oh.. happening here too. It was 100% when i left to the mall and now when im back after two hours, the battery level is 76% :/ i didnt realized this earlier, but when i saw this topic and remembered that i took my phone off from the charger the battery has run out quite quickly. So now i know why my phone shows quite empty battery on every morning...

This got me thinking that im actually charging my ipad pro (12.9) once or twice aday too..
 
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