This phenomenon happens once in a week or once in 2 weeks or so here is a screen capture in the battery menu from general under settings.
I have a XS Max with a Smart Battery Case
Sounds like Smart Charging. There's a setting somewhere in there for Smart Charge, buy which your device learns usage patterns and stops at 80% during upward charging, then pushes the last 20% just before it expects you to pull the charger and load the battery. I would guess if you're in the <wait at 80%> time slot it will also do a hold at 80% during discharge (78% is close enough!).
I thought the same but I always try to make sure to plug my phone in when the smart battery case is around 20% also I observed once the phone drains down with smart battery case it drains down till the phone is completely out of juice and then the phone restarts and charges from the case looks like the battery case is faulty.
Yes now my battery capacity is dropping as well
Hi albinjoseph,
It looks like you're wondering about your iPhone battery. If that's correct, check out the following resource.
Charge your iPhone with your Smart Battery Case
This should help.
Cheers.
Why does my iPhone drain randomly even when my smart battery case has some charge? Drains to 78% and back to 100%
