Level 2

158 points

iPhone 12 battery draining fast

Hi all,

Trying to work out if I have a defective unit I need to send back or if there's a wider issue here. The iPhone 12 Pro is advertised as having a smaller battery than the iPhone 11 Pro so I expected to have slightly reduced battery life (which is fine as 11 Pro was excellent).

However I'm noticing that the iPhone 12 Pro is draining when idle with almost no background activity at a rate of 4% which is much faster than my previous iPhone 11 Pro, and to be honest a faster idle drain than I can actually remember from a new iPhone. First instinct was to disable Mobile data to see if it was a 5G thing, but I actually don't see any real difference from doing that (which makes sense as I've been on Wifi 98% of the time since I got it).

No matter what I try, it seems to be going down oddly quick. Not to an useable level or anything world ending, but I guess its sort of suspicious. I check the battery report, and it's not showing any real culprit, just a rapid decline for no clear reason.

If anyone can share their idle battery with either 12 or 12 Pro I'd really appreciate it.

[Re-Titled by Moderator]

iPhone 12 Pro, iOS 14

Posted on Oct 25, 2020 8:14 AM

Top-ranking reply

user0197

Level 2

172 points

Posted on Jan 1, 2021 5:25 AM

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.

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2,818 replies

Nov 13, 2020 3:08 PM in response to Hugeman

I’m experiencing the same behavior. Even a full restore through my Mac did not fix the issue. Makes me wonder if it’s indeed hardware related. Otherwise it must be a software bug but this means everybody with an iPhone 12 pro is affected who uses dual sim.

Odiebla

Level 1

26 points

Nov 14, 2020 1:24 AM in response to Community User

I don’t run widgets on the Home Screen, only on the today screen.

here you can again see the impact of my 2nd SIM. When I disabled it during the night the drain was significantly less (but still not good)...

Lestat09

Level 1

13 points

Nov 15, 2020 2:55 AM in response to Sander_98

Well, I have never used the low power mode ever so that doesn't even apply to my case. As per experience, resetting network settings solved the problem for 5 days and now the 20 to 25% nightly battery drain came back. It's inconsistent. Can't tell if it's hardware or software. I'm on my 1st replacement and if this doesn't disappear before the 14th day, I'm returning it and will try the Pro Max but then someone has already reported on this thread that this battery issue also happens to the Max variant.

Deptors

Level 1

9 points

Nov 15, 2020 10:17 PM in response to Lestat09

Absolutely right! Here I read that there is a suspicion of a hardware problem ( modem ) I think it is not logical, because with a problem like this we have a very small percentage of users ! There is hope that iOS 14.3 will solve everything. My ipnone 12 pro loses on average 30% per night (all services are turned off)

Nov 16, 2020 1:35 AM in response to Master26A

Just got my iPhone 12 last Friday and I’m experiencing the same problem with battery drain when idle.

Overnight and when idle my phone drains on average 3 to 4% per hour.

I’m from The Netherlands
Using dual sim (eSim + SIM card)
No 5G, both lines are 4G
Using Wi-Fi 100% of the time (2.4Ghz with perfect reception)
Phone reception is great, full 5 bars for both lines
Have tried to reset network, turned off Exposure Notifications, removed all widgets, nothing works.
Weird enough is that one day I charged my phone to 97% and left it idle for 8 hours, after 8 hours the battery remained at 97%! However that only happened once, for all the other instances I’m experiencing battery drain.

Hope a software update can fix this issue.

Really disappointed with Apple, this is my first iPhone coming from Android and I’m starting to regret it, having to charge twice a day with moderate use.

Deptors

Level 1

9 points

Nov 16, 2020 1:56 AM in response to Odiebla

I noticed this problem when I used only one SIM (discharge about 3-4% per hour) then I transferred it to the e-sim, also did not solve the problem ! Now I use both e-sym and sim ... the same indicators (((

Nov 17, 2020 8:51 AM in response to Master26A

I am also facing the same issue with my iphone 12. Battery discharging around 25-30% during the night. Where as my partner's iPhone 11 just looses around 10% during the night.

Apple support ran all diagnostic tests and concluded that there is no issue.

darrengf

Level 1

4 points

Nov 17, 2020 12:07 PM in response to sevahrun0427

I received my iPhone 12 pro Max and this is the worst battery drain issue I’ve ever had in the history of owning a iPhone.

it’s shocking and it’s dropping anything between 1-3% per hour doing nothing.

woke up after a 7 hour sleep to a 23% battery drain over night,

Ive done the following

wiped it clean and started again from icloud

reset settings

reset network settings

Cleared everything down

tried single or dual sim, no differemce

5G off. No difference.

removed apps

installed apps

removed icloud

changed settings

it seems nothing makes any difference at all.

the phone drain battery quicker than anything I’ve ever seen.

I do expect some draining at first to index etc, but this is beyond a joke and coming from a iPhone 11 Pro Max that I could get 2 days use out, to a iPhone 12 pro Max and I get 10 hours Max or same use.

something is seriously wrong with what ever apple has done.

This is very very poor.

Adds526

Level 1

4 points

Nov 20, 2020 5:40 AM in response to Deptors

Yeah I’m single sim in the uk on Vodafone. 12 to 25% battery drain each night, Apple support say my battery is fine which I do not doubt, however something isn’t right. I’ve never had such battery drainage on an iPhone during standby

Nov 21, 2020 4:37 PM in response to Master26A

Yep, same issue here. Around 20% drain, sometimes more, overnight — no apparent tasks in the background under battery usage. I had the iPhone 11 Pro Max and I would only lose at most a few percent over night. Never experienced this kind of drain with an iPhone before. Must be a software issue?

Nov 22, 2020 7:20 AM in response to Lestat09

I have the 12 Pro Max and it’s great in every way (including battery life as a whole) except this issue that all of us here have, constant battery draining when idle (2-3% per hour at least). So great phone but not the solution to this specific problem.

Nov 23, 2020 8:52 AM in response to Master26A

That's right because iPhone12 has critical bugs for battery drain. My iPhone12 use 100% battery for I play lol wild rift by 6 hours. That's so bad because Android phone use 100% battery for I play lol wild rift by 20 hours. So, I say "resolve battery bugs" to developers at everyday. We must say "resolve battery bugs" to developers at everyday to and Apple recall all old iPhone12 & send new iPhone12 to us.

I can't use this iPhone12 without low power mode....

Nov 23, 2020 7:25 PM in response to maxwilkes92

iOS 14.2 doesn’t fix this issue for me.

iOS 14.2.1 doesn’t fix this issue for me.

I can only wish and hope that 14.3 can fix it.

If it is really a modem related issue like many have mentioned here, can it actually be fixed simply with iOS updates ?

Anyway.... in my case the abnormal battery drain happens only when both SIMs are activated.

BUT, even though I’m only using one SIM card now as a workaround, I still kind of feel like my iPhone 12’s battery life is not ideal, maybe worse than that of iPhone 11 and the previous XS max.

Can someone WITHOUT abnormal battery drain issue tell us, how is your iPhone 12/12mini/Pro/Pro Max’s battery life ? How may hours of screen on time do you get ?

Adds526

Level 1

4 points

Nov 24, 2020 1:34 AM in response to Domjanlaci

om On 14.2.1 have discussed with Apple support who say the device is fine despite it losing 15-30% per night. 15 percent last night on 24th November. I don’t have 5g enabled as I don’t have coverage here and I only use 1 sim. I have done a full restore twice from iTunes on Mac and it hasn’t fixed the battery drain. I have never had an iPhone drain so much to quick on standby. I have minimal apps installed without background refresh. Apple support have been no help unfortunately. I will be leaving iPhone next year if Apple don’t do something about this.

Nov 24, 2020 2:00 AM in response to aleksandar-iliev

in Hungary, we have great 4G/LTE coverage, the second issue is not a root cause. Apple simply changed to Qualcomm modems and it seems iOS can't handle them properly. We can only hope it's not a hardware issue.

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iPhone 12 battery draining fast