iPhone 12 battery draining fast

This post seems to have opened a complete new set of doors! All this while people have been complaining about the modem and modem firmware. Is this phenomenon across the board - i.e. carrier locked and unlocked devices. If it's occurring in carrier locked devices, then a modem firmware should come from the carrier more than from Apple. If it's across the board, then god help us and all we can do is wait for an iOS update!

My iPhone 12 Pro worked fine, with a logical and expected battery usage, for the first two months. Then suddenly about a week ago, without me changing anything on the phone or in my usage patterns, I started losing 50% - 60% of the battery charge overnight with no activity whatsoever (see graph from last night attached). I have executed my own investigation over all the usual suspects (background processes, notifications, mobile data, resetting the phone, etc. ) but nothing helped. I have contacted Apple Support, they ran the diagnostics on the phone with the conclusion that there is nothing wrong. I intend to give it another week or so to see if there comes a software solution but then I intend to demand a replacement.

My previous messages have been deleted - and I'm sure this one will too - but I'm not using 14.3, it's the next one.

Below you can see the battery drain is normal, last charged to 100% Sunday 10:23AM and currently at 13% on Wednesday 19:15PM with 'normal' everyday use (web browsing, calls, listening to music etc).

I upgraded from the XS Max to the 12 Pro a few days ago. I immediately noticed this issue as I don’t usually leave my phone on charge overnight. I lost over 20% during my 6 hours of sleep while my phone was idle, with 5g off !

This is an alarming amount of battery drain and I’m kind of regretting my decision to buy this, I’m worried this is a phone defect and can’t be fixed with a software update. Does anyone know if Apple commented on this issue?

Tonight I will be doing a battery test with my XS Max and 12 pro. Both will be 100% charged, and both will be set to Airplane mode. I’m almost certain of the result but just want to be sure.

I attached a picture showing the 12 pro losing just over 20% between 3am - 9am last night, with no activity.

Dont waste your time. My 11 pro max has been off the charger since 9:30am and 3.5 hours later with usage its still at 100%. I used my 12 pro max last night on wifi w cell data off last night for 5 mins and lost 6% battery. I am calling Apple now as I am fed up.

I am now experiencing the same thing for the second time and I’ve only had the phone for 4 weeks. Charged it at night until it reached 100% took it out of the charger for 2 hours without using it and then saw it had dropped to 95%. Left it on standby overnight for 7 hours and it dropped about 40%!!! (95% - 56%). This is really frustrating. That’s not to mention that some app notifications don’t work either... eg. Facebook and Instagram. It’s just been one incident after another debating whether I should return my phone and go back to using my iPhone 6. I’m now on 48% and I’ve only been using it for half an hour....

They are refunding me in full. I’m on my second phone and I think it’s the modem issue. I had to buy an 11 pro max before they were gone and it still is the best battery iPhone ever. Both phones on same iOS and the 12 just drains

Strangely enough, I am a little bit relieved because everyone who got their phone replaced eventually ran into the same issue with the new one as with the old one. That leads me to believe that it is most likely not an actual hardware defect or a specific range of serial numbers. It seems to happen all across the entire line.

What baffles me though, that not one serious video has been made on Youtube where one experiences the same issue.

Then again I contemplate wether it has something to do with the production date, since most of the tech reviewers get the earliest models.

After I stopped caring about and obsessing on this issue for over a month now, it seemed to have disappeared. On light usage, I'd charge my phone after 3 days with 45-40% battery remaining. On heavy days, I would charge after 36 hours with same amount of battery remaining. 12 Pro Max here. Even back when I just had my phone, it never died on me.

I had the same problem with my SE 2020. I don’t have an issue with how the battery drains while I use it, but it drains way too quickly while on standby. I lose around 4-5% hour with cellular data off. I’ve tried turning off almost all features, with no difference at all. Only thing that reduces standby drain is to turn on Airplane mode and keep WiFi and Bluetooth turned off, which makes the phone absolutely useless.

I’ve right now given it to the nearest service center and am waiting for them to give me a callback.

Wow, this is nuts.

On the other hand it is kind of relieving as it seems no hardware defect on the 12 series.

Did you notice the Standby drain after updating to a certain iOS version?

On my 12 mini the drain seems lower when I am using it than when it is in standby...

I think in this case it is a connectivity issue. The phone is trying hard to maintain connection to cell towers with maybe one bar and that is drawing much power. You should try turned on airplane mode on during that time you put your phone in a locker. Since you can’t know if you would get a call or message if you’re away from the locker, it doesn’t matter anyways. The metal enclosure isn’t the best for any radio waves to penetrate through. It’s why every iPhone that has not have had a glass black had some form of glass insert (5, 5s 1st SE) or had huge antenna lines (6, 6s, 7) on the back or on the sides, to allow those waves to pass through into the device.

Yeah but I get 4-5 hours SoT if I really stretch it. I shouldn’t see a percent dropping every 10 minutes of light use. Like on Reddit for example, I’m just browsing pics and commenting here and there, and my Reddit client is also dark mode so my screen is always as black as possible.

It’s not like my phone can’t last me a full day, but my old phone could usually last me a day and a half before needing to charge. So can this one but I still don’t get more than 6 hours SoT, and I don’t think I’ve even had that much on this phone before.

Finally I have been asked to submit my phone as the engineering team has identified the issue which needs further investigation. When I pressed the support person, she agreed it is a hardware issue. I will be submitting my phone tomorrow. I am not sure what issue would be addressed. Mine probably was among the first batch of phones as I ordered almost right at the beginning.

iPhone 12 Pro

I got my 12 pro two times replaced and I do have the issue with all of them. So either I should play some lottery now or hope it‘s a software issue...

So I don’t think it is a random hardware issue in some batches, but also strange why it does not effect more people then.