Forbes released an article about it last week. Here are the important bits... ”Indexing Blues iOS 14 is definitely to blame for your iPhone not lasting as long as usual, but it’s not because Apple has secret code embedded in the new operating system that “targets” older phones.  In the days after you install a new version of iOS, it’s busy doing all sorts of housekeeping.  The biggest one of these is re-indexing. During this process, iOS 14 combs through all of the data on your device so that it can be cataloged for quick Spotlight searching. This takes a ton of processing power and chews through battery life like a hamster through a cardboard box.” “So How Do You Fix Battery Life in iOS 14? Wait. That’s it. Nothing fancy. No toggles to hit. No battery health screens to check out. Just wait 24-48 hours. After a couple of days and a few full charge cycles iOS 14 will calm down and you’ll see your battery life return to normal. “

I don’t know if this will help anyone but I have an iPhone 8 Plus and running the most recent update has essentially solved my battery issue. It was BURNING hot and draining rapidly. Now it seems to be running like it was before