Solved for me: Someone in this thread suggested changing the home button. Mine in contrast to theirs was the original home button that I’d moved into a new third part screen. (It didn’t come with a button). The original button was Touch ID that stopped working.
So the battery would drain fast until eventually it was destroyed. (Too much charging and discharging).
The replacement button cost peanuts and I replaced the battery at the same time. Really pleased because I thought I might have to buy an original apple screen as people here have suggested. This worked for me anyway. Now I wake up and the battery is as charged as when I went to sleep. Bingo.