Some iPhone 12 owners are experiencing unusual battery drain on their new iPhones. While faster battery drain can be expected when you first get a new iPhone due to all of the app installs and data loading going on in the background, the users in Apple's Community. Support forums are reporting excessive drain even when the phone is in Low Battery Mode or on standby overnight.
User Master26A on Apple's Communities forums brought up the fast iPhone 12 Pro battery drain on standby even when their expectations were that it wouldn't be quite as good as the iPhone 11 Pro. They brought up battery loss of about 4% (per hour) on standby shortly after getting their iPhone 12 Pro in late October ... Since then, over 1,000 others have said they're seeing the same trouble. Many are seeing between 20 and 40% loss of battery overnight, and many have tried things like turning off 5G and turning off background app activity, etc.
The user had tried to turn off suspected culprits like 5G, but that did not have any impact on fixing the problem.
No matter what I try, it seems to be going down oddly quick. Not to an useable level or anything world ending, but I guess its sort of suspicious. I check the battery report, and it's not showing any real culprit, just a rapid decline for no clear reason.
Another user spoke to Apple Support and came away with the notion that it may be a bug that could be fixed in an upcoming update to iOS 14.
I spoke to Apple support today & they ran diagnostics saying that everything checks out. I imagine what this means is that there is a software issue causing the battery to drain – hopefully they sort it soon. It 100% isn't normal for all apps to be closed, background app refresh off, Bluetooth off & lose 40% charge overnight. To illustrate here's my battery view overnight.
Many users have responded to the post saying that they are seeing similar issues with their new iPhones.