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

Reply
Question marked as Top-ranking reply

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

Apr 28, 2021 4:53 AM in response to Master26A

I notice a quick drop in my battery after the last update. So I am hopeful that Apple will finally acknowledge this problem and fix it. Since the quick battery drain started happening after an IOS update, I'm hopeful that they will figure a way to fix it. As others have indicated, the battery meter doesn't indicate an app that is causing it, but I can tell you that when I go to bed if my phone is below 30% it will be dead by the morning. Not acceptable. This is worse than the 6s that I used to have that did have a bad battery at the end.

Apr 28, 2021 9:45 AM in response to ladan124

I too have the same question. I’m from india and spent approximately 1700 dollars on this iphone 12 pro which is thr worst iphone i have ever purchased. even my iphone 6 after 5 years functioned better than this peace of crap. Apple isn’t going to acknowledge this issue. I have tried contacting apple support a million times but they keep saying that the battery is normal. I have decided to destroy this 12 pro crap next year and buy the new iphone if its perfectly fine. I don’t even feel like selling this 12 pro to anyone because its a peace of **** and I would feel super guilty selling it to anyone

Apr 28, 2021 11:37 AM in response to ladan124

If they are, either they don’t care or they really don’t know what’s going on with their product ( I don’t even know what is the worse scenario).

Like people said, that is my worst iPhone in years. I feel like having a near perfect product isn’t in their DNA anymore (Too many bugs these past years ). I don’t really like android phones but that might be the last resort for me if things don’t get better

Apr 28, 2021 9:27 PM in response to mar263

What do you mean by two charging levels?

when the battery is yellow it just means that you’re on low battery mode. And if you charge it past 80% it turns green to a normal usage of the battery.

If that is what you’re talking about, i think you’re just lucky that things seems to be back to normal for you. And you must be the only one so far I’m afraid.

Apr 29, 2021 9:40 PM in response to krish280

Same here. I know it's a moot point to complain, but I like complaining and complaining to the "Geniuses" have not helped. "It's working as it's supposed to"he says, as the battery drops 3% in the 3 minutes he's holding the phone to check the settings. Needed an oven mitt to handle the phone after he handed it back, or an egg to make breakfast. Former Fanboy needs a fan, boy, to cool off this brick oven. Anyway, if anyone's hungry, come by Williamsburg BK, I'll make y'all breakfast on my iPhone 12 Pro.

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iPhone 12 battery draining fast

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