I honestly don’t believe this to be a software issue, at least not a bug that can be fixed properly with a software update.
I think it’s amazing what Apple can do to optimise their OS and software to use as little power as possible. However, I honestly think that Apple have been a little too optimistic this year. They’ve overestimated how much software, combined with the A14 5nm can do with regards to power management. If Apple had of kept battery capacity’s at the same level as last year, added to the A14 5nm chip and software optimisations power efficiency would have been much better.
with that said, I believe this battery drain issue to be a problem with the modem it’s self. Look at Android phones with the same modem (The Qualcomm X55 I believe it is) they’ve all had similar issues. The modem used in the iPhone 12 series is known to be less power efficient than other modems available. Apple are switching to the Qualcomm X60 (I may have the model names slightly off) next year for the iPhone 13 series, which, is a much more power efficient, and all around more capable modem than the one they’re using this year.
sadly, I honestly don’t think we will see a real fix for this until the third quarter of 2021. Apple will already be aware that battery drain is a real concern on the 12 series, so, they will need time to either make replace models and start a replacement programme, or, release a statement informing iPhone 12 series owners to take their devices into their local Apple stores to be repaired there and then. I’d guess that the first scenario is more likely. Sadly I can’t see this issue being fixed with a software update, no matter how much Apple may try. I’m not even going to contact Apple support because, for me, personally I’ve two choices A. Return my device or B. Hold off and wait for the inevitable recall later on in 2021. If this issue is widespread enough Apple may indeed need to offer replacements with different modems, which offers its own problems because all future iOS updates for the iPhone 12 series may be fragmented due to differences in modems. If Apple do indeed go with a modem change and replace devices though I’d hope that they’d do this for all iPhone 12 series devices across the board.
I’m very happy with my iPhone 12 Pro Max, but power consumption does concern me. If I compare battery life on my 12 pro Max to my XS Max there really isn’t much difference at all. The 12 pro Max has ever so slightly better battery life than my XS Max, but not two generations of iPhone better. My partner had a regular iPhone 11 with an LCD display and her battery life puts my 12 pro Max to shame. Considering that my 12 pro Max has an OLED display that uses less power than regular LCD this doesn’t reflect well on the 12 pro Max at all. My 12 pro Max has acceptable battery life, but from a phone this big, with a 5nm chip, and all of apples software optimisations I’d expect a solid 2 days battery life for my personal usage. These are the settings I use on my 12 pro max:
5G is always turned off completely.
Background app refresh is always turned off.
Bluetooth is turned on for around 1 hour each day.
Location services are on for around 1 hour a day and then disabled as is mobile data.
I’m connected to WIFI all day and night.
Dark mode is permanently enabled and I use a dark wallpaper.
Automatic brightness is enabled.
with the above settings I’m getting through a day easily, but I’m disabling features that are essential really and listed along with the device as, well, features. If I turn background app refresh on, mobile data, Bluetooth and 5G my 12 pro Max can’t make it through the day.
one thing I’ve always enjoyed on iPhones and iPads is the standby time. Usually I can leave my iPhone on my bedside table at 100%, go to sleep and wake up 7 hours later with 100% battery life, or 99% worse case. My 12 Pro Max drains 15-20% whilst I’m a sleep for 7 hours with only WIFI enabled. I can get that to 10-15% with lower power mode enabled.
my 12 pro Max also seems to get too hot every few hours. A complete shutdown then power back up resolves the heat issue so perhaps the battery drain is being caused by the modem getting stuck in some kind of power loop.
anyway, I look forward to reading other people’s views and options on this issue and let’s hope there’s a fix on the way sooner rather than later.