iOS 16.1 Battery Drain

This seems to have solved my problems:

https://www.droidwin.com/iphone-calendar-app-excessive-battery-drain-fix/

Numerous users have voiced their concern that the Calendar app is hogging an astronomical amount of battery from their devices. Users have reported that if they check the Battery stats for the past 24 hours, then the Calendar app is sitting right there at the top, running for over 15 hours in the background and around 83 hours in the last 7 days.

Correspondingly, it seems to hog around 40% of the battery which is definitely not what one would expect from an app belonging to this domain. What makes the matter worse is the fact that Calendar isn’t even present under background app refresh, so you cannot disable its background activity as well. With that said, there does exist a nifty workaround that shall help you resolve this bug. So without further ado, let’s check it out.

Nearly all the users who were getting bugged with this issue had one thing in common- they were all using the Apple Watch. Upon further debugging the issue, it turned out the issue is the watchOS. So here’s what you need to do to rectify this bug once and for all.

1. To begin with, long press the Calendar app and select Re-Arrange App.
2. After that, tap on the minus icon to remove this app from your device.
3. Now unpair your Apple Watch from your device.
4. Then reinstall the Calendar app on your iPhone from the App Store.
5. Finally, pair your Apple Watch with your device and the issue should be rectified.

That’s it. These were the steps to fix the Calendar app excessive battery drain issue on your iPhone. If you have any queries concerning the aforementioned steps, do let us know in the comments. We will get back to you with a solution at the earliest.

I am experiencing the same behaviour on my iPhone 13 Pro. Usually the battery is great. I have low power mode enabled for most of the day so I can get about 3 days on one charge. I am not a heavy video or video game user. But then suddenly overnight I loose about 50% of charge and most of it is consumed by Siri. This happened to me twice. To get out of this, I had to completely disable SIri and reboot my iPhone twice after disabling Siri; yes twice. If you rebbot only once, battery drain continues even after Siri is disabled completely. Also, it does not help to only disable some Siri features. Only after completly turning Siri OFF (and 2 reboots) battery drain stopped.

This is what I ended up doing to get my battery under control and still use the iPhone for my important functions such as Texting (iMessage), using MS Teams (for work), Banking app push notifs. etc.

1.     Turn OFF WIFI globally, completely. (Not from the control center)

2.     Turn ON the Cellular Data (Mobile Data in EU)

3.     Then go to Cellular (Mobile in EU) Data settings (scroll down) and turn off data for each individual app only leaving those mentioned above.

This way you eliminate the battery-draining network traffic that is probably caused by some apps. You might want to turn on your essential app's data one by one and see if the battery starts draining as you turn some app's data ON.

Now my phone consumes very little battery (second screenshot) and I can use my phone until the official fix comes out; hopefully soon. Of course for this to work, you have to have a solid data plan.

I bet if you keep Wifi OFF and then also turn OFF cell data, the battery drain will stop. You will basically have only a phone (without any data). You can also experiment with turning cell data back on and turning off data for each application separately in the cell data setting at the bottom. That is what I did. I just allowed a couple of apps to have data turned on and the battery is great. Interestingly enough, in my case, I had Contacts consuming 8 GB of data and 90% of battery. I have about 400 contacts. As soon as I turned off data for contacts, the battery drain stopped. But I think it's random. For you, it might be some other app that has a runaway process.

I had the same problem, that since iOS 16.1 my iPhone 12 Pro was empty within hours, even though it was only carried around in my pocket.

After a few days of analysis I found the cause:

As soon as iCloud is activated, the battery problem starts.

I observe a massive data consumption in the mobile data network.

So I reset the data consumption statistics in the settings and observed which app generated the consumption.

In my case, the address book (contacts) was massive in data usage.

I turned off iCloud syncing of Address Book (contacts) and lo and behold, battery consumption returned to normal.

I would also like to note that I had previously analyzed the processor load via Xcode on the iPhone and it was permanently unusually high. Only after disabling address book (contacts) synchronization did the iPhone's average CPU load drop back to a normal level.

My conclusion:

There is probably a bug in the address book (contacts).

I hope my post helps you.

In case minimal iPhone usage and battery drain, have a look the high data consumption apps: in my case it was the Contacts ???!!! As the Contacts was already in sync with other clouds, I disabled the unnecessary (duplicate) Contacts sync with iCloud: Settings - your name - iCloud - iCloud Apps - Show All = turn off Contacts. At the same time turned off the Calendar due to same reason.

Battery drain disappeared.

Have a nice day!

I had this problem a few ago, the iPhone 14 Pro was constantly warm and the battery drained really fast. "Home & Lock Screen" was always on the top of the battery usage. So I called the Apple Support and they told me that I have to totally reset my iPhone (Recovery Mode) via my MacBook.

Before I had to Backup my iPhone to my MacBook via Finder (Spoiler, I never used this backup again).

How to back up your iPhone, iPad, and iPod touch with your Mac - Apple Support

After that I restored my iPhone via Recovery Mode

If you can't update or restore your iPhone or iPod touch - Apple Support

This took a while. After that I activated my iPhone and did NOT restore it from a backup. Because I want to be sure that it isn't a hardware problem. Since this day everything works fine. I have enabled every iCloud sync again. Everything without any problem. 90k Photos are back on my phone and my whole HealthKit Database is back.

I know setting up an iPhone from scratch is a pain, but it's better than a battery that least only half a day.

iOS 16.1.2 updated high hopes... bizarre same problem continue: when enable Settings - iCloud - Contacts (backup to iCloud) the battery drain starts (together with Contacts abnormal data consumption) - and vice versa back to normal when setting disabled. d'oh 🥜🥜🥜🥜🥜

Confirming the latest couple of posts here. I have an iPhone 13 Pro with 92% battery health -- of which the health of the battery dropped from 98% to 91% after the ios 16.1 updates. The past few weeks, my phone has been losing 8-12% an hour and running hot with it just sitting there and not much activity. Actually using it for anything that you would want to use a smartphone for drained it even faster. I have both called Apple "customer service" and visited the "Genius" bar and everything checked out and they couldn't find any issues with the battery or the ios. I explained to both that there are known threads out there describing these issues that many are experiencing, but they had no knowledge about it. Not sure what the point of these boards are if Apple doesn't actually review or assist and they leave their customers to fend for themselves. Pretty poor all around service when they won't acknowledge known issues.

I disabled contact sync earlier today and that seems to have solved the problem. If I find the battery drain has continued after a few days, I'll update here. Hopefully, ios 16.2 fixes this issue when it is released next week and we can turn contact sync back on. There should be no reason we have to dumb down these smart phones.

I had this problem for a couple of weeks and tried *lots* of things to fix it. My battery drain was due to extraordinarily high battery usage by Home & Lock Screen, between 50-65% of all battery usage was due to this. One of the following resolved it for me (I say "one of" because I tried two things in succession):

• I used DFU mode to wipe the phone and reset to factory specs. Once I got that set up and working I then restored from my iCloud backup. This didn't immediately resolve the issue, so then I,
• Removed the Photos widget from my home screen.

After a couple of days my iPhone was back to normal battery usage and I added the photos widget back and it remained good.

This was all very frustrating, but I never for one second thought of switching to another platform. I've heard enough support nightmare stories to know that the Android world is no better, and often substantially worse. When you have over a billion devices all over the world, running an endless number of hardware/OS/software combinations bugs will happen and it *will* be difficult to troubleshoot them all. But in my experience they always do get fixed eventually.

I updated to 16.2 and while standby time seems okay, battery drain starts as soon as contacts sync is enabled again and I start using the phone. Battery dropped 15% in just 15 minutes of use. Turned of contacts sync and battery drain is fairly normal again. So no, I don’t think Apple has addressed this issue yet.

Also had a huge amount of background activity on the mail app while on charger. Deleted the internet accounts and added those back again solved that problem.

Battery drain continued via Contacts app (high data consumption) after I enabled the FaceTime, but now after disabling it seems back to normal. To find the problematic app it was helpful to (temporarily) disable the WiFi and reset the Mobile Data usage calculators under Settings > Cellular or Settings > Mobile Data. High amount of Contacts data (transfer) usage is not normal. There must be something wrong on Contacts data sync or related services somehere - changed after 15.7.1.

Two weeks now of crazy battery drain. Spoke to Apple Support twice and their only advice was to wipe the phone and reinstall from backup, which did nothing but waste several hours. For me it’s the Home & Lock Screen that is using 50-60% of my battery, all while off screen. The phone gets *hot* while just doing normal tasks and the only solution is to turn on low power mode. This has been the most disappointing iPhone update in years and I really hope Apple is able to figure it out.

Yes, my iPhone 14 pro max is draining like crazy after 16.1.2

Siri drains almost 40% over night (without any use) in just about 8 hours.

So for now I’m disabling Siri completely.

Apple needs to fix this because all in all it kills/destroying battery health over a shorter time.

Still on 100% battery health but not for long I guess if Apple don’t come with a fix soon…

I do have the latest .2 release installed after my DFU wipe and the problem is gone. Remember that very often after a software update they're a lot of battery-intensive background tasks like reindexing the phone, which can take a day or so.