Batteries are kind of like our bodies, where if we exert a lot of energy doing tasks, we’ll get tired faster compared to if we just sat around doing nothing. This means that in theory, batteries in standby should last considerably longer than compared to if they were being actively used to run apps, take photos, watch videos, and so on.
However, some iPhone 12 users are discovering that isn’t the case with their phones. A growing number of users are reporting that even when their phones are on standby mode, which means that they are not in use, they are experiencing rapid battery drain where overnight, it can result in anywhere between 20-40% battery loss.
Obviously even in standby mode, battery drain still happens, but in theory it should be at a much slower rate as the phone is effectively not in use, so a drain of 20-40% overnight does seem excessive. Some users have taken their devices into Apple where upon a diagnostics check, it seems that their batteries are fine.
This has led to speculation that this could be a software bug with iOS that could be causing the drain. Not everyone is affected by this issue so if you’re not, count yourself lucky. However, if you are, then we guess you have no choice but to wait for Apple to release a patch to fix it.