New iPhone iOS update

There are several threads, including one long one, about battery drain and iOS 14.6.

If you just updated keep in mind that your Spotlight index has to update which will use battery and you will be getting a lot of app updates. If you have automatic updates turned on that will also consume your battery at a higher rate.

Give it 72 hours to a week and see if your battery life settles. If it does not go to Settings > Battery and see which apps/processes are using most of your battery. You may have an app that went rogue like Facebook is prone to do.

You can also do a Google search and find complaints about increased battery use after updates going back to iPhone 1.0.1

I'm sorry to hear about the issues you are facing after updating to iOS 14.6

There have been some reports of users experiencing problems with their battery decreasing slightly faster than normal after upgrading their iOS, Apple will likely fix this in a future update.

You can find out more information about battery, charging and optimising your battery to get the most out of it here