iPad notification to Iphone
How do I have my iPad notify my iPhone when the battery is fully charged?
iPad, iPadOS 14
There is no straightforward way for your iPad to notify your iPhone when its battery has been fully charged.
If your iPhone and your IPad are signed into the same Apple ID then you should be able to see your iPad in the Find My app. If you click on your iPad in the Find My app (on your iPhone) then you should be able to see the battery charge level. This is not as easy as getting a notification however it is a workaround for you.
Axel F.