iPhone 12 battery draining fast

This happened to me also with my iPhone 12 pro. Just this morning, around 3am when I unplugged my phone it was 100%. Then when I woke up at around 730am, it was only 64%. When I checked who's the culprit, it says it was my accuweather background activity doing her job 3hours+. I was asleep the whole night then this happened? It really ****** me off :(

A. I haven't inserted a sim since the day I bought it.

B. what is "cell mast", no cellular/network or mobile data in my phone since I don't have a sim inserted in it.

C. I am from Pakistan, unfortunately, there's no official support from Apple :( there are resellers of Apple products only..

D. My iPhone 12 Pro had the same issue before and after the latest iOS Updated.

That tends to happen when your battery is aging. Percentage calculation is no longer accurate in this case. Usage then draws current from the battery, the voltage drops, and then the phone recalculates it's percentage estimate. Have a look at the battery health state, chances are it's already 80% or lower.

This sounds really abnormal for the phone to drain out like 40-50% overnight. I think apple has restricted the drain to about 10% overnight with their updates which is still not normal but its better than a 50% drain. Losing 25-30% per hour of usage is very strange. Its quite a lot of battery drain. One thing, its a waste of trying factory reset’s on your phone restoring from itunes its all a complete waste. Apple doesn’t have any solution to this problem and are not willing to even accept this fact because of their aim to complete a certain level of sales.

I faced the exact same issue as you described. I’m already down to 95% battery health and now even i get two days of moderate use only if i use it on wifi. On LTE it drains fast. I’m attaching a photo of my battery graph on LTE below.

That is very bizarre, because I too have noticed that my battery is a LOT worse on my home Wi-Fi. Right now I’m on a trip out of town, and my battery is hardly draining at all on all-day hikes (unless I take lots of photos), just as I’m used to. When I’m at home, I get a drain of 10% per hour or worse.

I have my iPad, WATCH, Powerbeats Pro, and half of my AirTags with me. No iMac, HomePods,

or other HomeKit devices. What else could be causing this issue on home Wi-Fi?

The Music app or others being listed in the battery consumption is false information, and misleading. If there is any background process from iOS itself causing this, and that's not listed there, there percentages get screwed up and whatever apps were active get blamed for it. Ignore that.

Regarding the home Wifi to Lohvarn: do you have Macs running in the same Wifi?

Ok, if you have a guest wifi, try that, or try using the regular home Wifi with the iMac shut down for a few hours. My hypothesis is that some communication between the Mac and the phone keeps happening, draining the phone's battery. I would be great to get another confirmation of that.

That’s an interesting theory. My apartment was recently being repaired from the flooding caused by the February winter storm (Texas); my iMac was off the whole day, and I do vaguely remember that both my iPad and iPhone’s batteries did not drain like crazy that day. I’ll have to mess around with that.

Do you have Content Caching enabled on your Mac?

I have three Macs (with my own Apple ID): two laptops and a server, and content caching is enabled on the server. I already experimented with different combinations of them being shut down or active, and the results were inconsistent.

Exactly, what I have seen. I feel like the battery has an internal clock that is not idle so people who use their phone often don’t see anything. I am more random with use , some days a lot n others not. I have talk to Apple about this discrepancy. Also when I use gps or FaceTime, it drains quickly . My mom’s iPhone 11 Pro is so much better battery, I have done comparison usage. I just want Apple to fix this or give me an 11 pro

I bought my 12 pro in December 2020 and the battery health is already 94%. Biggest disappointment is this iphone. The lidar scanner may be useful for a few but it just heats up the phone making it a stove in hardly a minute and the lidar scanner drains the battery so fast almost 2-3% every minute which is extremely frustrating. Apple should realise their mistake but doesn’t look like because they aren’t even addressing this issue till now. I’m pretty sure apple has already lost a large market and if this continues they will lose more and more customers soon.

In my case its always been a steep decline of battery (not quite as steep as yours but still abnormally steep for idling). Only thing up to the point of unsubscribing from the mobile dynamic IP package was to use the device in airplane mode with Wi-Fi calling whenever I was able to connect to a Wi-Fi network. I just lived with the heavy drain when I was out and connected to LTE. But I always knew that it had something to do with the cellular connection. But its strange that in case it seems that only the Wi-Fi connection is the issue. Weird!

I know a couple technical things but too little to know example what pcap files are etc. But did you try to completely reset your router, 'unlink' all devices and manually re-connect all of them one by one again.

Wait...you are saying that if you use airplane mode and connect to your home (regular?) Wi-Fi network, the drain is gone???

Hi Lohvarn, thank for bringing this forward. I'm reluctant to disable bluetooth on my phone, but of course will do to help narrowing this down, and try all the suggested combinations. Disabling bluetooth alone doesn't change anything for me though. And the "ask to join personal hotspots" setting was always set to "never" on my phone.

I want to start with the Finder setting, but I can't find the option "show on Wi-Fi". I currently have a German UI, so wording is of course different, but I don't see an option that sounds similar. Can you specify more precisely where that setting is?

For context, my Macs are on wired Ethernet, but that's of course connected to the Wifi the phone is on. One is on Big Sur, two are on Catalina (2012 hardware).

Over the weekend I was away at another's place, with Wifi, and obviously I had no battery problem at all. I also feel that my iPad Pro 11" 2020 is affected too, but of course to a much lesser degree because the battery is so much larger (if the same amount of processing happens there with the same Wh consumption, that's of course a much smaller percentage of the battery capacity).

Could you check your YouFone contract details and check wether there is a mobile dynamic IP package active? I recently found out and deactivated mine (drain curve looked EXACTLY like yours) and now my battery drain also looks exactly like yours before the blue line and after the red line. With airplane mode and Wi-Fi calling enabled I even get better times, I get a standby drain of roughly 1% every 2-3 hours which is great. 3% loss over night is much more satisfying and acceptable than then steady 1% decline every hour when airplane mode is not enabled. It seems, in 'regular mode' one can't get better times than a minimum of 1% every single hour. I contribute that mostly to the cell reception and the fact that my phone does not connect to 3G very often anymore. I live in a rather rural area and 3G coverage still is much better than LTE, yet the iPhone will continuously choose LTE over 3G (I do understand that download speeds are probably faster with a 1 or 2 bar LTE signal than a 4 bar 3G one, but I am connected to Wi-Fi anyway, so that doesn't matter at all . Especially in my house I usually have 3 bars LTE (top floor) but it drops to 1 bar in my kitchen (ground/first floor) and I really notice that the battery drains much faster when while I am in my kitchen. Sometimes it connects to 3G for a brief second (especially after just toggling off airplane mode) and its always 3 or 4 bars but it always switches back to LTE after 30 seconds or so. Hate the fact that my carrier doesn't allow me to force 3G anymore