iPhone 12 battery draining fast

Why?

It will only keep it charged at a 100% which in turn is bad for your battery.

I know iOS has the optimize battery charging feature. But that is only useful when you have a regular routine and not when you have irregular work shifts (night/day).

Far a device that cost over € 1000 I expect that the battery doesn’t drain that much when idle. Or that it will at least point out to you where the drainage is coming from.

If it can’t than it’s a design error or a bug that should be fixed by the manufacturer!

Confirmed now, my phone only consumed about 1% per hour during the night, so about 10%. Still more than I would to see from a complete idle device but acceptable and in line with what I’ve seen on older devices. I forgot to mention that I also toggled “low data mode” on, on the remaining 4G eSIM. So now it’s time to check the low data mode and the second SIM to see what exactly triggers the insane drain overnight. I’m curious to hear the experience of others with these tips.

Dude this is fukked up! I have the same issue but not like this. The first days I figured out 5G drain a lot. I mean A LOT but after i turned it off the next night the lost was about 3-6% perfect for me. The very next night it started again. No apps in background. No email push. No background refresh. Like always, WiFi und Bluetooth on and data mode turned off.

i think I’ll go to the apple store

I'm having the same drain issues using dual-SIM setup. When idle with dual-SIM its about 4% battery an hour of battery loss. Without dual-SIM it is about 1,5% battery an hour of battery loss.

I tried several other things as well like reinstalling the device but for now it just seems to be the dual-SIM that is causing all the battery drain.

Hi Busaku, Odiebla and ApplePears88. Thank you very much for your support.

I did an hard-reset (boot) and it did not fix the problem. And I was wrong about the energy saving mode, it was draining the same level. When I checked the graph, the yellow was dropping at the same rate as the green graph.

I'm testing tonight the Battery management. It's activated on my phone actually. I will deactivate it, hard-boot (will always do it from now on when testing things) and see if there is a change. Saw that playing with it for some people did it...

After that, if it still does drain the battery the same, I will erase my phone and see with the plain OS without importing stuff from my old 11 Pro...

That will probably be my last test before I go get a refund on my phone. I'll probably buy another one later when they fix this problem either on the iOS or Hardware...

Absolutely right! Today’s night my phone lost only 1% per night(8h), but that happened to me only with the airplane mode ON. The phone stopped heating while browsing social network, safari etc. I’m absolutely sure that the problem of heating and drain is related to a new x55 Qualcomm modem, and I do think this is a software issue. Hope apple will fix this.

Proof of the heating problem is caused by an X55 is the fact from too many users on a Russian 4pda forum, when all of us switched into the AirplaneMode, all of the games were stopped losing frames and the throttling is near to be gone

You are mistaken. first of all, now all models dual-sim: one regular card and one esim or two regular cards. Second: I have this problem on sim+esim model, moreover, when two cards are active, when any one card active - in any cases when 4G is active i have battery drain.

Why don’t you just follow the best practice of charging overnight, every night? There are processes that happen all the time, 24/7. When the phone is locked Wi-Fi turns off unless the phone is connected to power, so all processes that require data use cellular data. Which is the heaviest battery user after interactive gaming. Leaving it connected to power overnight has multiple advantages:

• If you turn on iCloud backups the phone will back up every night
• You can enable Optimized charging
• Wi-Fi remains on, so no data updates will use cellular data
• The running processes will use mains power instead of battery power, thus reducing the need to use charge cycles; as battery life is measured in full charge cycles this will greatly improve the useful life of the battery.

Your explanation is right to the point. This is exactly what’s happening and the issue must be the DSDS driver they use in iPhone 12 pro. Because the same sim setup worked flawless on iPhone 11 Pro as well as iPhone SE 2020. Hope everybody here follows the suggestions to submit feedback or call Apple support. My case got escalated and I’m hoping on a response from Apple next week.

factory reset etc. will not fix this issue. Thanks for your suggestions about the beta, if I don’t receive a satisfactory response from Apple I’ll submit the feedback through beta.

This is wrong. Please refrain from further comments as they do not help with the issue in this thread. The problem is the new DSDS driver on iPhone 12 pro. Probably also the regular 12 but I have no way of knowing. On iPhone 11 Pro etc. the same dual sim set up did not cause abnormal battery drain. A correctly functional dual sim standby does not cause double energy and battery consumption. If this would be the case there wouldn’t be any dual sim phone in use.

me too. Have an iPhone 12 single SIM and I’m loosing 15-25% every night while idle. BUT! last night I went into airplane mode and turned wifi off. See there I lost only 1% battery during the night. It has to be a problem with the Mobile data or SIM service. I’ll also report my issue to Apple. That’s a big thing

The other day, I posted that my replacement unit has excellent battery life. Well yesterday my phone was fully charged at 5pm and I tuned DND on. I didn't use my phone until this morning at 7am. So that's 14 hours on idle. I was again surprised that this new one discharged 17% of battery on standby just like the previous one. I have the dual sim version. Apple should do something about this software bug. I remember my 11 Pro Max. It remains at 100% for 24 hours on standby with active cellular network. No kidding.

Yes it is. in my case, my phone uses

7% overnight (8 hours) With only physical sim and 35% with the e-sim also enabled. And this is the case with more users in this discussion. And for the record, all iPhone 12 models are dual sim capable.

Agreed. I was responding to the 7%. For the 35% with 2 lines, what is the signal strength on each line? Cellular data and voice adjust power output based on the signal strength of the network access point. With 5 bars the phone can maintain a connection with 50 mw transmitter power. For 1 bar that goes up to 600 mw. And, if the phone is not plugged in, all data updates overnight use cellular data. And if you have 2 lines active the power required for the cellular connections is additive.

And the solution is still to charge the phone overnight.

Really? This fixed it? My cellular data has been the same as default voice line. So I’ll try to reset network settings. In my case this might make sense as I’ve transferred from my former iPhone instead of setting up as new. Is your battery still behaving normal?