I have an iPhone SE 2020 with iOS 14.2.
If I turn on Optimize Battery Charging, my phone loses about 40% of its charge while sitting unused overnight.
Anyone else experiencing anything like this? Check your charge before going to sleep, don't plug in or charge your phone, and see how much remains in the morning. Do with with Optimize Battery Charging enabled, and then again with it disabled, and let me know what you experience. Thanks.
14.3 is waiting
Please upgrade to 14.3 and see if this remedies the situation.
Re: iOS 14.3
I upgraded to iOS 14.3 yesterday and re-enabled Optimize Battery Charging. My phone lost eight percentage points of charge overnight, which is a huge improvement relative to the 35-40 percentage point drain under iOS 14.2. I'll consider the issue closed, but I hope Apple continues to make improvements, as even eight percentage points for ten hours idle is undesirable.
I personally also observed some battery drain issues under iOS 14.2, though not as dramatic as I've seen others report. For me rebooting the phone resolved the battery drain, but it would return a few days later. As far as I know, the update to 14.3 resolved the problem, but it's too early to tell for sure. My device is an iPhone SE from this year.
I never tried disabling the feature to optimize battery charge, so I don't know if it had an impact or not.
More results from iOS 14.3
With iOS 14.3, my iPhone SE 2020 loses 8 percentage points overnight regardless of the Optimize Battery Charging setting. This issue is closed.
I had the same experience with excessive battery drain. I found one of the culprits wasn't battery optimization but was the COVID tracker. I didn't want to, but I had to turn it off or just give up on having a portable phone, and if I'm not going anywhere then I don't need the tracker.
My iPhone 8 is old and has been very heavily used so I can't expect much from the battery, but I hope 14.3 will prove to be an improvement over 14.2.
With Optimize Battery Charging turned on, my battery drains fast
It shouldn't lose 8% at night. that is nuts. I have the covid tracking and battery Optimization turned off. I'll watch it. I noticed it drained a lot in 14.2.