iPhone 12 battery draining fast

So, it seems that the problem comes from my physical SIM since, with it activated exclusively, and with the mobile data off, the drain is still evident.

After I reverse it (eSIM on + physical SIM off) and still no mobile data, the drain has stopped as illustrated by the yellow circle:

Can anyone try to replicate this behavior?

I can clearly relate to what’s going on. When i first bought this 12 pro, it ran ios 14.1 and i used to charge at 36 hour intervals. All was fine but then i upgraded to ios 14.2 and now i am losing 20% battery on an average.

Here’s what happened last night, at 11 i checked my battery was 81% and when i woke up at 8:30, my battery was at 51% with no visible activity on the graph.

I only use a single physical sim and i only use WiFi, so I don’t even know what’s causing the problem.

I would not have say this, it is linked for sure to network and more likely to the network chip.

Indeed, on my iPhone 12 pro Max I have an eSIM and a physical sim with the same provider (pro & perso). The phone is also linked to my cellular Apple Watch (which is in charge by night).

Yesterday evening I have tried to switch off the physical sim and the drain was very low.

(please note that it remains a long time at 100% because according to coconut battery the battery has 250 mA higher than the design capacity, so it drains but remain virtually at 100%).

here is the graph

When the two sim are activated, it gives this

As you can see the wifi is on and the network is not so bad ;)

I want also to add that my iPhone 11 Pro Max with the same config, iOS 14.2, Apple Watch linked, in the same place, two sims and a battery at 96% didn’t experienced battery drain.

I started nights at 100% and woke up at 100% during my tests... And of course, at the end of the day my battery was in average much higher than on the 12!

So I have still in mind to return it to be refunded before January 8th if it is not solved.

Dear Apple,I am sure you're following this thread !!! So when your clients call you to report this problem, PLEASE don't tell them this is NORMAL behaviour of a battery !!!!

Almost 24H since i last charged the phone, and in that time i only had a 8 MINUTES of screen on time and i lost 40%.

I already tried 3 different carriers sim cards here in Portugal and 3 Esim...and guess what,no improvement...I tried with only physical card, only Esim and both. As long i am getting no support from Apple, i really hope the media starts even more to coverage this problem.

Exactly I have the same issue with my 12 Pro from the day 1. I notified it when the battery was at 22% at around 10 pm, and it was completely switched off when I checked my phone early morning at 6 am.

Apple support ran diagnostic test and found no issues with the device and battery.

Service Center told me to reset the phone. I reset my 12 Pro, and restored the backup.

I tested with low power mode on before going to bed at night, with WiFi off, location services off, and I even changed the old SIM and inserted a new SIM. Finally Nothing improved the battery drain.

It drains battery in the same speed with or without low power mode. The phone’s battery drain is almost 2% to 3% per hour without doing anything, which accounts to 14% (2% x 7 hours) overnight.

Here is the screenshot of battery graph with, and without low power mode.

I am not gonna tolerate this anymore, for device with that price-tag and it is almost unusable, before i go to sleep it is charged for like 80% and in the morning it is 40%, before the noon phone is OFF, WTF ??? (And in my case it is 12 PRO Max) This is happening to me almost every day, I am just charging like crazy, it will significantly decrease my battery life for the future. I will wait no more thx. Apple but take your battery addicted phone back.

Aaaaaargh.

Fcking apple.

My first message was written at the beginning of this thread, I’ve already tried everything.

I saw that some guys replaced their physical sim with esim and it’s helped.

But NOT FOR ME.

80%->64% for 8 hours.

So, Vodafone UA users, esim will not solve this issue. Returning to physical sim has some inconvenient. Don’t waste your time for it.

For sure, but he is unfortunately gone :(

Here is the result of the last night, really better than usual but it is still not normal to loose "so much" battery by night.

Especially knowing that my battery currently has 200 mAh more than the design capacity, so approx. 5% more, which means that it virtually goes from 105% to 92% in 6 hours.

Adding few bits from my experience thus far.

Device: iPhone 12 128GB

Location: India

Physical SIM provider: Airtel

eSIM Provider: Airtel

I have read much possible comments on this post - over a period of time. Have been following this thread for long now, even before it was picked up by Forbes.

All I got to say is based on my own experience and experimentation to validate some of the recommendations provided here by other users. This is not the desired state in which I wish to operate my device!

I "believe" (like many others) it relates to "modem firmware", and I do agree with the statement "that's not why I purchased this device" as many have stated. Also this may not even be a workaround for regions where there is only 4G / 5G+4G OR with individuals who would majorly be on Mobile Data for communications.

Okay, with all that said, ONLY state in which the battery usage is what could be called "Normal / Acceptable" - as per my experience, is with 3G selected for Voice & Data. This is an "okay" state for me as long as I am on Home WiFi, with WiFi calling enabled. The moment I step out and enable 4G, I get back to "Ground Zero".

What I am more curious is to see if  addresses this in future update for Modem Firmware.

Until then, I'm just dropping this post here, along with screenshots.

updated to iOS 14.3 last night, WiFi on, no 5G, Bluetooth off. Battery drain 16%

2.00 am 87%

7.45 am 74%

problem still persists. Where I live they don’t replace the phone or refund :(

really frustrated.

attached screenshot

when typing this message I have lost another 2%. Well played Apple.

i think the mystery is resolved ..... i switched off the cellular data last night , only connected to wifi .....0 percent drain

i have already returned 12 pro but the pro max also didnt turn out different .......bettry drain starts while connected to cellular data .

i will switch on cellular tonigh and would share tomorrow

I still have a too high battery drain on my Iphone 12 Pro, ios 14.3.

All updates I got since buying the phone did not solve this issue.

(LTE, hard SIM, Congstar in Germany, modem 1.31.03-5, Telekom.de 45.0 PRL 1)

If I leave my home for a walk, drain seems to stop. You can see it in the image after the charging.

Is there a way to get more information about the type of LTE connection? I had such a tool some years ago using android.

I hope there will be some message from apple soon. It would help to see that there is hope. In my personal opinion they hurried up with 14.3 to sell the new headphones and fitness service, and now they have some time to fix hardware issues with 14.3.x.

I would like to help to solve this problem, but I found no person from apple to listen right now...

Left side of the graph: before 14.3 (IOS 14.1) and right side after upgrade to 14.3. Same conditions on both, with a slight bit more of 4G usage yesterday than today (all day in connected to WIFI).

Clearly a difference but it is enough for me to keep the phone? I cannot see an alternative for it if I want to have a small form factor coupled with high performance specs. I guess my only hope is that Apple solves it in time since they have a lot to loose if they don't.

I thought I’d test dual sim mode on 14.3. It started fine, but then it got worse as time went by. By the end of the 3rd day it’s draining like crazy. Going back to single eSim mode again...

eSim - EE UK

Sim - O2 UK

The weird thing is that O2 signal is a lot stronger than EE, but enabling O2 causes the drain. Makes no sense from signal strength point of view.

So it looks a lot like a memory leak. Who knows

Replacement iPhone 12 Pro Max

Night 6 Selected 4G, manually selected O2, connected to home wifi, mobile data off, background refresh off, low power mode on

15-12-20 22:00 battery 92%

16-12–20 09:09 battery 75%

Putting aside the battery issues, everything else is good. The hardware is ok I think, so won’t be returning, it’s such a pain to swap over and migrate banking apps etc. Looks like 14.3 probably won’t make any difference to battery situation for me, but not making it worse. Will update today.