iPhone 12 battery draining fast

Guys, I think I found the solution. When I got my iphone 12 pro brand new, I restored my backup from icloud. The battery was draining fast after I did that. I now reset all content and setting. The battery is doing very well. If you are having the same issue as I did, try this and it should solve it.

I am having the same issue with my 12 Pro, losing 3-4% battery on idle during the night. I also got it already replaced and the new one seems to have the exact same issue. So waiting 6 weeks for the replacement unit did nothing. Thank you👌

I now created an automation running every 30 minutes to log battery level in a file on iCould.

I also did some previous analysis, playing around with setting disabling everything etc, without any significant change.

Now the interesting part, I figured out that battery draining is only happing with an inserted SIM card! (Flight mode does not have any effect), only removing the SIM card from the iPhone! I also think it has to do with the modem only!

I am using Telekom (Germany), perfect signal, wifi connected. So poor signal should not even have an impact, because wifi.

I am going to switch to eSIM tomorrow, hoping to fix it with it.

Results

19.12.20;00:00;67;LTE

19.12.20;00:30;66;LTE

19.12.20;01:00;64;LTE

19.12.20;01:30;62;LTE

19.12.20;02:00;61;LTE

19.12.20;02:30;60;LTE

19.12.20;03:00;59;LTE

19.12.20;03:30;57;LTE

19.12.20;04:00;55;LTE

19.12.20;04:30;55; noSIM

19.12.20;05:00;55; noSIM

19.12.20;05:30;54; noSIM

19.12.20;06:00;54; noSIM

19.12.20;06:30;54; noSIM

19.12.20;07:00;54; noSIM

19.12.20;07:30;54; noSIM

19.12.20;08:00;53; noSIM

19.12.20;08:30;53; noSIM

19.12.20;09:00;53; noSIM

LTE + wifi: 12% in 4h idle -> 3% per hour

no SIM + wifi: 2% in 5h idle -> 0,4% per hour

Another night (not perfect without SIM, but definitly an improvement!

I am too facing the same issue on iPhone 12 mini, iOS 14.3. I was using iPhone 7 ans I just upgraded to iPhone 12 min, I was satisfied with iPhone 7 battery backup with my usage and iPhone 12 mini seems to be very bad. Battery drains fast. I am getting a max of 6 hours of screen time where apple says more than 10. Based on the comparison it should get more than 2 hour compare with iPhone 7. Is there any solution for this?

Here are the results after one night in standby ok my 12 pro max. It is better than before but still not as good as my 11 pro max, as far as I remember.

To be sure, I have restored it today. I will let him make all the update/indexation process plugged in tonight and test tomorrow and tomorrow night.

iPhone 12 Pro

iOS 14.3

Dual sim mode

Main line: eSim: EE UK, data off

Secondary line: Sim: O2 UK, 4G data on

Third day in a row, no major battery drain. A bit strange combination, as I have eSim enabled as my main line but with mobile data off. For mobile data I use my secondary O2 line with 4G enabled.

If I enable eSim data then it drains at least 3-4% an hour. And the only way to use eSim data without battery drain is to completely disable physical sim line.

As I told, I have restored my previous iPhone 11 Pro Max (from a finder back up of my 12 Pro Max) in order to make a real comparison between both battery performances and drains under iOS 14.3

So here is the values for a 11 Pro Max with dual sim Orange and with WiFi, Bluetooth and apps background refresh activated. Just as everybody should use and enjoy its iPhone actually ;)

It has been use moderately at office during the day, not connected to WiFi until from 4pm but it seems to have no impact, and then a little bit more at home with a phonecall of almost 1h on WiFi Calls with Airpods used.

It wasn't the same say but here is how the 12 Pro Max under iOS 14.3 performed in a similar use (moderate at office) in the circled area, even if it was less light than above according to the diagram ...

Back to yesterday, over the same period here is how the iPhone 12 Pro Max behaves with the same settings, except dual Sim of course

After one night, here is the 11 Pro Max (left at 67% at 10:45pm and find at 60% at 7:30am) which depletes at approximately 2.5% each 3 hours in the beginning and then 2%:

Here is the 12 Pro Max over the same period which depletes at approximately 1.5% each 3 hours constantly:

As a comparison, the last one ;) , there is how the 11 Pro Max depleted just after the activation of the 12 Pro Max in the same conditions (still configured but without SIMs) at approximately 2% each 3 hours constantly:

In my remembers, the iPhone 11 Pro depleted slowly than the 12 Pro Max, especially from 100% but they seem comparable here. Strange ... I will observe it a few days more and keep you posted.

I have the issue also with 2x iPhone 12 (mine and girlfriends) since the release. I didn't post here but followed your suggestions and findings. Thanks for sharing them!

Mobile network of both devices: 4G, Vodafone DE, physical SIM.

Btw. the workarounds you guys mentioned don't work for me. I can not select 3G on the mobile network menu, just choose between 4G and 5G. And when switching networks manually to competitor networks it does not connect successfully to them.

I didn't contact Apple support yet since I've read here your experiences with them regarding this issue and don't really want to return the devices. Is there a fix for this issue coming?

My sad & constant battery usage:

Actually it is hard to say about this. Indeed I use the same operator on both SIM and I have always used the data of my personal contract (eSIM).

The phone is currently in charge, I will continue to use the eSIM data tonight and tomorrow. Then for tomorrow night and the day after I will switch the data to the physical SIM in order to see if there is any difference.

The day after, I will switch to the 12 again.

Here is today’s values

Here is a similar day at office with the 12 Pro Max on iOS 14.2.1 for comparison. Actually the use was even a little lighter.

I noticed the exact same behavior with my iPhone 12 Pro. I am with the iPhone since the 4s and never had an issue like this. I already changed my physical SIM with an eSim, but no change at all. I am with T-Mobile in Germany (Telekom.de).

This is my battery usage at home:

This is my battery usage when staying at the house of my girlfriend:

Same phone, same apps, but very different behavior of the battery usage, just by changing the location. The cellular network is strong in both places, thus a little bit stronger at my girlfriends house. But with my iPhone 11 Pro, the battery usage was quite the same in both places, so definitely an issue related to the iPhone 12 (or the modem or whatever).

Tonight I went from 46% to 38% with an iPhone 11 Pro Max, between 11h45pm and 7:30am!

Are they making the old ones draining to hide the drain on the 12?

And here is the 12 Pro Max idle since Sunday without SIM but still configured and with the same background activity theoretically. Its last charge is from Sunday late evening.

A simple workaround kinda fixed it for me. Before my battery has been inconsistent. It would be stable for 2 days but when it reaches 70-60%, the battery drops like crazy. Like 5-10% in 2 hours.

So while tinkering with the phone, I changed the cellular option from LTE to 5G Auto and the battery drain stopped. As you can see, since I enabled 5G Auto, the battery drain looks like a straight line. No more downward slope.

This is mine, again, iPhone 12, this is at night being idle. From 73 to 3% just idle during sleep. Background task off, Siri off, Raise to wake off, set to use 4G and not 5G

This is not normal for e brand new phone..... :-(

Just look:

it was 100% at 16.19 hours Saterday, look at the usage: hardly used at all! Just lying there being idle! With background tasks off, Siri off, Raise to wake off and not even 5G on!

not even 24 hours idle time!

Do not tell me this is normal Apple!

So this is the only your conclusion with your personal situation. I’ve seen only one feedback telling that nothing had been solved and this is yours. And I’ve seen thousands of feedbacks on a very popular tech forum in Russia, all the users in Ukraine, Russia, UK are reporting that the very latest firmware is fixing that issue. If you saying that this problem is happening even with airplane mode ON - this is not a modem issue in your case.

In conclusion: you will never tell me what I would tell and what I wouldn’t. I can and I will do everything I decided to to do and to tell.

this is my graph with latest fw that totally fixed everything

I don't know if iOS 14.4 fixes it but what is for is that even at idle with no SIM it drains faster than the 11 Pro Max. This is probably due to smaller capacity of the battery.

Here is a comparaison between the iPhone 11 Pro Max and the 12 Pro Max at idle without SIM and configured identically.

I have used the 12 Pro Max several weeks, then tried again my 11 Pro Max for one week and I am back this week on the 12.

Here is the 11 Pro max vs the 12 Pro Max in idle without SIM on a Monday evening whereas they have been unplugged the Sunday at only 30 minutes of interval (earlier for the 11)

the 11 Pro Max

The 12 Pro Max

We clearly see that even with a 1 year old battery, the 11 hit the 99% at 11am instead of 7 am for the 11! And the 11 has been unplugged 30 minutes earlier and had more background activity than the 12...

Now here are the same phones on Tuesday morning, still unplugged on Sunday evening.

11 Pro Max (7:35 am)

12 Pro Max (7:42 am)

Slopes are similar but if we look closer, we see that the 12 depletes faster. What a surprise would you say me...

And finally the 11 Pro Max vs the 12 Pro Max in use on a Tuesday morning, the phones haven't been unplugged at the same hour so don't compare the battery level but only the slope of the battery level ;)

11 Pro Max

12 Pro Max

Yesterday I went to bed at 9:30pm with 50%, I woke-up this morning with only 42%.

I have left my home at 8:30am 40% for a walk of 30 minutes to my office without using it and it was at 37% once in the office at 9am...

Now at 10:10am, with only having sent the screen-captures by mail to my desktop computer, I am at 35% ... So I have lost 15% for 12h in idle and less than 20min of screen time.

What an incredible achievement Apple engineers!

It is a fact for me, even without the amazing drain that I experienced in the beginning and that some of us are still facing, in idle without SIM or in use, the 12 Pro Max has a lower endurance than the 11 Pro Max.

And as far as I remember it is the first time that an iPhone has a smaller battery life than it predecessor... But we are in 2020, nothing should surprised me anymore.

Actually, the iPhone 12 Pro Max is a great and high tech phone but do not consider it if you need endurance...

Thus, keep you 11 Pro Max or even buy an iPhone Xr if you can deal with lower performances. The 12 Pro Max is a real F1, but you will have to refuel it every night... Especially if you have a heavy use.