When my battery is fully charged I would like a Notification Sound. It used to make a certain tone.I went to my settings, and tried to find it there but it gave me no information to do it. I tried searching Google but it was of no help. I look forward to hearing from you. I hope someone could help me.
Why don't you try an app for the purpose? On Google Play, a search for "full charge notification" brings up e.g. Battery Full Notification. I've just tested that app, and it works for me.