It is not good for batteries when they are fully charged. In order not to forget to remove the charger, it would be good if a notification is sent when the battery is charged to a certain level (like if the battery should be charged, but with the message that you should remove the charger).
Many manufacturers offer the ability to actually set a charge limit, and we do expose that in the UI. I'm using it on my computer (a Lenovo ThinkPad X1 Yoga) to stop charging at 90%. That's the best way to do this. Showing a notification for this on unsuppirted hardware would be super annoying if we did it by default, and if we didn't, nobody would ever find the feature for it and you would grow tired of being nagged anyway. :)