Hi All,
I have exactly same problem with my iPhone 7+.
It had suddenly bricked and I spent so much time to restore it and finally I restored as a new iPhone.
but the remained battery is 1 % or 100 % always and never changed.
And when I disconnect the charging cable, It turned off tens of seconds later.
I checked the battery health and found the current capacity of the battery is 100mAh.
Is there someone can help this?