Hello kmldrx,
Thank you for using Apple Support Communities!
We understand from your post that an app called "install macOS Big Sur" is on LaunchPad and the battery percentage doesn't match up from the Launchpad to your Desktop. In regards to the "install macOS Big Sur" app you see, it can be removed using the steps below:
Use Launchpad on your Mac - Apple Support
"Add or remove an app
Apps that you download from the App Store or that are included with macOS automatically appear in Launchpad. If you download an app from another source, you can add it to Launchpad by moving the app to your Applications folder.
Learn how to delete an app from your Mac, which also removes the app from Launchpad."
Regarding the battery percentage being different, test the issue while in safe mode. Then restart your Mac as normal and see if the issue persists.
Start up your Mac in safe mode - Apple Support
Best Regards.