iPhone 12 battery draining fast

No more problem after restore and set up as new. Look at the nice and normal battery curve. Though, just using single sim now. Dual sim is not fixed but I’ve bought a Pixel 4a for the second sim, back to two phones again but actually works nice for me distinguish work from personal lines 👍🏼

So after doing a lot of messing with the iPhone and checking things out. I’ve actually located what is draining my iPhone 12 pro Max at an alarming rate when idle

Ive been watching the battery slowly deplete when the phone is in idle. Especially over night as I don’t use it as much.

what I’ve since learned is that the dual sim mode is the cause of it,

if I use one SIM card only and the dual sim is off, the battery behaves pretty normal and also the battery graph represents the exact same.

so where the circles are dual sim is active and you can see the battery deplete rapidly. As soon as you turn of the dual sim, the battery acts normal and the phone seems ok as you can clearly see and battery use is normal.

the red line was when iOS 14.2.1 was installed and yes it depleted a little. But when I switched the dual sim on. Look at that. The battery depletes rapidly yet again.

So for me, the Dual sim activation is the biggest culprit and is a massive drain on the battery and the phone never feels cool to touch. Not hot, just not cool.

so the modem is the biggest issue. Bad drivers or something really bad in the iPhone

while writing this which is on the iPad, the phone has dropped 1% in 10 mins doing zilch with dual sim on.

Interestingly, after an update of 14.2.1 83% from 9 p to 12 was no bits at all ! And after 12, the beginning gradually drops to 73% to 4 am, then I turned off the sim, leaving only e-sim and power saving mode ... Flight smooth to 9 am ( the modem firmware became 1.14.06 )

This is interesting. I changed my background to live again this morning and look at the battery curve. It started draining again. Constant drain 45° Downhill, now I turned it off, back to a still wallpaper and the battery acts normal again.

can it be that simple? 🤷🏼‍♂️

I also have this issue.

Using only one physical SIM in Germany (Telekom)

The last nights my battery drained in a range of 20-30%.

This night I used the Airplanemode with activated wifi.

the battery only lost 3%.

I hope there is coming a hotfix for this issue.

Same issue here... I'm using the iPhone 12 with one physical SIM (German Telekom 4G) for 4 weeks and tried everything.

When I received the phone I transferred a backup of my iPhone8 first, after some days I did a complete fresh install, and then I tried something else every day (eg. a reset of the network settings, a hard reset, a soft reset, I even reset my WiFi router some days ago).

As you can see on the screenshot it doesn't matter if I'm using the phone or not, the battery drain is more or less the same.

My iPhone 8 used about 3 or 4 percent battery overnight and the iPhone 12 about 3 or 4 percent per hour when idle...

Hopefully this is software related and Apple is aware of this and will fix it soon.

In the evening, completely ruined the phone to zero that it would turn off, then put on 1A charging, from 3 am to 9 am result 100% ! All services are included

and WiFi, e-sim, widgets are off ! Is the problem with widgets ? Try it the same way !

Hi, my iPhone 12 Pro has the same battery drain when idle. It seems to be related to the SIM.

No SIM = Battery drain 2%

SIM inserted = Battery drain 25-50%

I read that iOS 14.3 (beta 2) solved this issue for some people. Can anybody confirm this?

After tweaking up with my basic tips I give you before. My iPhone 12 Pro phone was in idle mode in about 9 hours under the night. I also use E-sim on the phone...

Here you can see the result:

I only lost 9% of the battery for the whole night 😊

Try switching from LTE to 3G (if you don’t have 5G) I have the iPhone 12PRO after full discharge and charging (1A ) up to 100% holds 30 hours and my charge is now 67% (all services are enabled ... e-sim ), also I’ve disabled all the widgets ! One of the three actions helped ! Good luck 👍🏻 Attached last 30 hours

Ok guys...I have iPhone 12 and use dual sim. Last friday I turned off my e-sim and the batterydrain was 3-4% in idle mode over night. Yesterday before bedtime I activated my e-sim and this morning, as you can see, the drain was a fact! So, in my case the problem is running both sim at the same time. With this in my knowledge, is there a shortcut how to activate/deactivate my simcards?

I have done full settings and content reset to defaults, but it does not help. Also I've had chat with apple support with performing diagnostics, but they say that everything is OK with my device. Minus 35% per 3 idle hours. I definitely tend to think that it is not OK.

That looks really bad and certainly is not normal. Apple support is no help at all at the moment.

I did a restore, clean install, using finder on mine. Set up as new and now the battery is fantastic. Look at the screenshot. Before it looked like yours even though quite frankly not as bad, more like a 45° constant drain.

But this fix for me only applies to using one sim, in my case eSIM Telekom Germany. As soon as I insert the second sim the battery drain is back. This is a serious firmware bug.

Well, back on LTE after a successful experience with 3G in standby mode ... and battery drain back , -25% per night ! ( LTE is just eating up the battery at an inexorable speed doesn’t matter sim or e-sim)

I can confirm that using 3G worked for me as well. Usually my phone on LTE was losing around 30% battery overnight, on 3G for around 8 hours on idle it went down by only 3%.

I don't mind using 3G for now, because I'm at home most of the time.