Question: Q: iPhone 12 battery draining fast

I strongly but politely ask to refrain from cheeky responses. Of course we know you can charge a phone but a) many choose not to charge lithium batteries while sleeping and personally I think that is a good habit and b) many are not capable of charging overnight for whatever reason and c) it's beyond the point. The point here is that there is a clear battery drain and I think we as the community all benefit from it when we can identity the issue and have it resolved. iOS and iPhones should and can do much better and the iPhone11 clearly demonstrates that. Also, my tests clearly indicate there is an issue. Enabling low data and switching of my second SIM has dramatically changed the discharging curve and actually now shows a more normal discharging behaviour where there is a clear correlation between usage and rate of discharge. When the battery drain is present there is no such relation: the phone just discharges at a fixed rate, despite the actual use. That is not normal and it's perfectly legitimate to complain about it.

We're not complaining just to complain, at least I'm not. I'm complaining and we're putting efforts in it to come to the root cause and have it fixed.

There is nothing for Apple to fix.

These "battery drain" posts have been here for the last 8 years. None of them have any value or purpose other that for some people to say "me too".

I tried using low power mode overnight having charged to 100% - by morning I had only lost 3% battery. This sounds great however, to achieve this, I stopped all apps background refreshing, and used low power mode. To compare, I charged my iPhone 8 Plus (which battery health says the battery is significantly degraded) to 100% did not stop background app refresh and did not use low power mode & lost 3% battery rate. I may try the hard reset that others have mentioned & will let you guys know how that goes!

That is simply not true, I'm an engineer working in the mobile telecom industry and the discharge rate currently seen on my iPhone12 is a faulty curve. I feel no point in debating that, as this is just a simple scientific observation that I already cross-referenced with a known-to-be-good situation both both the iPhone11 and the iPhone12 under normal conditions.

Please check both curves, on the top you can see a drain, regardless of any handset usage during day OR night AND despite low-power mode. Any engineer can tell you this is abnormal behaviour. On the bottom you will see a 'normal' discharge curve, where you can clearly see it's not a straight line down the hill but is depending on usage etc. Note: both are made on my iPhone12Pro, the bottom one differs in 1) no second 5G SIM (in 4G mode only) enabled and 2) low data mode mode enabled on the first primary eSIM. I'm currently testing to see what actually caused the difference in discharging by disabling low data mode on the first eSIM. If the discharge rate continues to be 'normal' then there is a clear indication that enabling the second SIM caused abnormal behaviour. That is not 'me too', that is just a normal observation. If you think it's normal then you're perfectly entitled to that opinion, but then there is little you can contribute in this topic I'm afraid. It is my personal and professional opinion that this is not normal and considering the fact that Apple has accepted bug reports, fixed the issue and contributed them to me in the release notes I think I'm still doing a useful job here :-)

my 12 Pro looks exactly the same. Never seen this on my iPhone before. I believe it occurred after 14.1 update but I’m not 100% sure. No plateau just straight downhill.

I confirm, the curve is as your top one and now I remember, this issue started when I’ve put in the second sim. I’ve now deactivated data in the second sim to see if that makes a difference.

I tried this yesterday & it seems to have solved the issue for me. I only lost around 4% overnight without needing to use low power mode etc. I’d recommend others experiencing the rapid idle battery drain to hard reset!

Same issue here. I've owned every iPhone that came out since 2007 and this is the first time I have experienced something like this. Losing 18 to 20% on standby at night time which isn't comparable to previous iPhones that would only lose 0 to 2% overnight. Wifi and Bluetooth are both turned off. No apps running in the background. App refresh turned off. Mail push and fetch turned off. Tried rebooting. I factory reset my phone twice. And the battery drain is still there.

However, I tried turning on airplane plane mode overnight and the battery didn't lose a percentage of battery. So I reset the network and battery still drains. So this is a perplexing issue.

Yesterday I tried the hard reset method as well but still, 15% battery drain over night.......... I hope apple will fix this problem.

Are you using your iPhone in dual sim mode?

Yes, i have Dual-Sim

I bought an iPhone 12 Pro 256 Cosmic Gray. I already had an iPhone 11 Pro 256 Black.

I have no SIM in the new 12 Pro since I'm waiting for a flip protector case that they did not have at time of buying, before I do use the new 12 Pro phone. I know I'm parano but I prefer not taking chance to drop it.

I was charging it anyway since I wanted to test new features like Lidar. I saw it was draining fast the battery and was not too worry at first since I still have my 11 Pro and Lidar may be the factor here.. And I never look at battery life time with my old phone either since it suited my needs.

I began to log my use of the device when I let it completly unused on the table and it was at 23% at the end of day. I also rebooted the phone just in case and removed all App from "Task Manager".

here is my last log :

Nov 2, 11:37 AM unplug it leaving it in Airplane mode (remember I don't have a SIM in yet)

4:01 PM 88% left

9:18 PM 66% left

This morning 7:57 AM 23%

Here is the battery report: (my phone is in French but you should be able to understand)

Now I'm testing it with Energy saving mode still in Airplane mode.

I have the battery management mode enable too. That's my next test...

Will let you know.

Did you try hard-reboot?

Yawn.

Maybe try the hard reset as this seems to have solved my battery drain issue...but my graph looked very similar to yours before doing the hard reset