iPhone 12 battery drain overnight

After a couple days of experimenting.

Let me give you scenarios/examples with no regard to any other settings other than those mentioned being turned on or off.

iPhone 12 Pro running iOS 14.3

SIM card installed, WiFi on, Cellular On, Bluetooth in Standby (Turned off in CC to disable new connections, but still enabled)

Battery drops between 15 and 30% over an eight hour time frame while not being in use. (This was the case for a couple days, until I realized something was clearly wrong)

SIM card installed, WiFi off, Cellular off, Bluetooth standby same as before

Battery drops around 10% over the same time frame (Better, but still not satisfying)

Now get this!

SIM card taken out, Wifi on, Cellular off, Bluetooth same as before, I also turned Airplane Mode on for the sake of it

Draining between 1 and 3% , over the span of 8 hours.

I know, it seems absolutely silly to use an iPhone without a SIM card, but as long as this bug is not fixed taking out the Sim card might be your best option to prevent your battery from draining over night. Or you just simply keep it on a charger. Keeping the SIM and at least turning off WiFi and cellular or putting the device into airplane mode should make the battery drain a little less too.

Some other things you might want to switch off, if only to test for a couple days to see if battery life improves and slows the drain. Keep in mind, you can disable everything temporarily and don't have to worry about anything breaking. If something needs a certain thing enabled, iOS will most likely give you a prompt anyways. You can go back and enable everything again, but until a version of iOS 14.3.x or 14.4 is released that addresses the those kind of issues, it's the best and to be frank, the only thing you can do.

• Location Services > System Services. Be bold and turn off EVERYTHING. Toggle the status bar icon (the switch on the very bottom) so when you slowly enable them one by one again, you can keep an eye on what triggers the location to update. With the status bar icon on, you can check and investigate closely how and when a certain service is updating. I found the Find my iPhone location feature updates like crazy.

System customization also updates in the background constantly ( if you turn it off, Dark Mode/ Appearance will still be able to work in sunset/sunrise mode, night mode however will work only when you put it on a custom schedule, and optimized battery charging will not work (even the option itself in the battery menu is enabled) if you have Significant Location and/or System Customization disabled).

• Put Bluetooth into standby so it stops searching for new devices (Toggle it via Control Center so the icon becomes white.)

• Turn off 'Ask to Join Networks' and set 'Auto-join Hotspot' to Never in Wi-Fi settings to stop the device from constantly checking for sources, notifying you and trying to connect to other routers.

I don't mention any of those things like turning off Background App refresh, dimming your display etc as those can be found in literary every 'iPhone battery savings' video or article.

It is clear that the issue can be pinpointed to the cellular modem, which can only be put into completely pause if there is no SIM card in the device. Airplane mode alone does not seem to fix the issue fully nor does turning off Cellular data help much if anything.

Hi all, I solved the issue for my iPhone 12. Turned out I had a bad celular reception in my home, only two out of four, and I didnt even know it. This apperentry makes iPhone work hard just to stay connected even when you use wifi (to be able to receive calls) and only airplane mode turns cellular connection (not data.. connection) off. I was loosing 20-30 percent per nicht and it was awful. What I did is activate Wifi calling. My carier Telekom In Germany supporst it. Today I lost like only 6 percent while the alarm on my phone was going of for an hour or two. So the battery drain overnight could be even smaller

TL;DR poor celular signal at home causes battery drain. Use wifi calling

I personally know as minimum 5 people facing the same problem but they just don’t care) people who care sometimes don’t know where to find for a solution, they just know nothing about forums like that. And this is not the only forum about that problem. In Germany, China, Russia, users are reporting that problem widely in their local forums. That happens only when you are connected to a special carrier line Vodafone in Europe, MEGAFON in Russia. But iPhone feels good with another carrier. So that might a kind of incompatibility between Base stations and iPhone’s new modem.

the only thing that solves that problem is to enable the AIRPLANE MODE or switch your cellular data to 3G instead of LTE.

this problem is massive, but conditions of the phones usage are different, carriers are different. If somebody will install a sim of problematic Servise Provider, right from that moment the problem is going to exist.

As a test, I disabled sleep/bed time schedule (available in the health app) and the rate of discharge was about 50 % less.

The phone was charged to 99% and after about 6 hours of night time, the battery was at 93%.

so definitely the bed time schedule is doing something crazy.

Then something is not right there.

I would recommend you do a backup, then restore.

See this link for guidance. If you do it using your home computer with iTunes, it will put a totally fresh install of iOS on your phone, which in your case may make the most sense.

Click here --> Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Click the Restore From a Computer Backup to see how do it that way.

My previous post was modified by Apple because I said that the battery drain problem was NOT the result of phone configuration. I should have said that despite configuring my phone to minimize battery usage, the rapid draining continued to occur, and required me to replace the phone. Users can reduce battery use by various means, but I experienced a problem with my battery that required hardware replacement, and the people posting here quite possibly may be facing the same issue. Hope this post is not deleted.

No it’s not a bug in the operating system at all

If you have no or very weak 5G service the phone hunts and poles in an attempt to find a tower constantly using up power to do so.

Turn off 5G in the setting

If you have one of those social media apps especially TikToc, those are the poorly optimised software and exponentially eat battery power . Again QUIT THEM fully before sleeping the phone AND turn OFF back ground refresh in the phone setting now

Do these two things and you will see a massive improvement in battery life

Hey everyone, iphone 12 mini here. I posted on this thread before about my huge drain overnight, usually more than 20-25% per night.

After playing around with some settings my battery only went down by 5-7% last night.

In the mobile data settings (i do NOT use dual sim as other people have noted) i turned low data mode on, even though i want to try it without this tonight, and then in the Mobile Data settings i scrolled all the way to the bottom and turned off Wifi Assist and iCloud Drive. The last two definitely improved my battery drain for some reason, so give it a try.

Many people on this thread have speculated that there must be a correlation between the battery drain issue and the new iphone 12 line’s connectivity.

We have obviously not changed countries, but yet our brand new iphones have a huge battery drain issue that is somehow improved when u downgrade from LTE to 3G or sleep with flight mode.

i too believe there is something with the connectivity, obviously with the new 5G technology something may have gone wrong and we’ll see whether this can be resolved or not.

i’ve been sleeping with flight mode on for anyone interested, and my battery drain went from 15-20% to just 5% so i guess that’s something.

I don't know from where you guys are switching from 4g to 3g. iphone 12 doesn't have any 3g enabling options on its cellular menu. It only has 4G/LTE and 5G switching options depending on your carrier. some has 4g and 5g and some has LTE and 5G. which is by default set as 4G or LTE but in case off excessive use of internet you can toggle it to 5g. Furthermore data mode is by default set on Standard basis. which can also be change depending on situation you need. I think the area or carrier of your iphone doesn't has the ability of 5G yet. that's why you guys can toggle between 4g and 3g.

But I also have find some solution for me as I was very upset because of this from pas couple of weeks. After discussing and diagnosing this problem with apple care they suggest me to Restore my iphone from itunes. I did the same as they advised me So restore my cellphone with itunes after taking backup and I think finally I am relieved now. my battery percentage only dropping from 3 to 5 percent from last 3 nights consecutively. I turned of wifi with both sims are enabled (No flight mode) in one night and other night turning on Flight mode, only setting I change is I Enabled Low Power Mode and it working great now. I will update it if I face some problem again. But right now it is going good.

I have been using airplane mode for 5 nights now, I have WiFi and Bluetooth on so my phone isn’t completely disconnected. There is no drain with this settings and that is showing it must have to do with mobile modem in my case. Sins I have WiFi on my phone it isn’t disabled from internet and if it was a app that causes this drain it most likely would drain even in airplane mode with WiFi on.

I also have this problem and there is a longer thread about this elsewhere. Try not using bedtime mode if you use that. I noticed that the problem is very visible during the night and always starts at midnight and that happens to be when my bedtime mode activates. Tonight I tried activating bedtime mode earlier in the evening and the phenomena starts right away. A steep battery drain and Siri using 100% background.

jazzrabbit,

Just to be fair, I decided to NOT charge my phone while I slept last night. I didn't turn off Wifi. I didn't turn off Bluetooth. I simply let it sit on my nightstand in DND. My phone lost about 4% of it's charge from when I went to sleep in 7 hours.

If your phone is losing so much when you sleep, you've either got something running in the background which is doing that or you may have brought something over from your last Phone which is corrupt. You may have some setting not configured properly. This is by no means endemic to all iPhone 12 phones.

If I had your issue, I'd restore my phone to factory and NOT restore it from backup, but bring things over, such as Apps, photos, etc.,

I still stand by my recommendation to charge your phone when you sleep as a good practice and one which will preserve battery health long term.

No one here knows and even if they did, publishing it would be a violation of the NDA they signed.

If however, you are waiting for an update to fix your issues, it most likely won't. No one I know with iPhone 12, 12 Pro or 12 Pro Max is experiencing the drain some of you are. This means there is most likely something you brought over from your previous phone when you set it up which is causing the drain.

It would be advisable that your do a backup restore and your issue will likely go away.

See this link --> Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

iPhone 12 Pro Max

iOS 14.2.1

Go to Settings>Mobile Data>Data plans>Primary>Network Selection>Toggle Automatic off and choose your carrier manually.

Tested this fix today in my usual use case.

Time: from 6:30 to 17:30

Battery %: from 100 to 82

Before it was from 100% to 50%.

Drain fixed I think.