Battery charging

[Bick]

Have a,S21 plus. I have always put my phones on wireless charger at night.  Brought a new charger yesterday.  Put phone on charge last night with phone, at around 50% battery.  Phone showed that it was connected and charging.  Several hrs later got up noted that phone was at 99%. Great I thought.  Got up and the phone was at 84%!!!! Why wpuld the phone discharge on a charger??   Any thoughts? 

[Ragety]

Weird coincidence maybe, but...
Put on wireless charger at midnight at 1% woke up later in the night and noticed phone not charging and was on 84%! gave it a wiggle and it reconnected and carried on. 100% in morning.
It's in a case so figured not quite in the area to charge. I don't think related to your problem but the 84% thing weird.

[GoanGeek]

I believe it fast charges until 30% then medium until 80% and then slow charge if you charge overnight.
You should always have 100% when you wake.
I believe it uses your sleep wakeup pattern to decide that.
Day time should take around 1 and half hours to fully charge
I have the Ultra though.

[szocher]

same problem with s21 ultra. wireless charging overnight. wake up in the morning and 73% charged. I used same charger with my note 9 and 100% every time

[kevinmcmullen668]

I bought a new charger for my new  S21+ i also have it in a case, it starts charging figuring it would fully charged in the morning but it would be 72%, and my wife uses a cord and hers would not be fully charged either.. What gives is there a setting that stops it from fully charging does anyone know