Explanation:
This is a Samsung tablet from 2014, currently has LineageOS 18.1 (Android 11), the last it can get. Since it's unused I did a little experiment until I find someone who will use it. Today I have found so here is the post.
After charging it to 100%, I disabled Wi-Fi connection, put it on battery saving mode and it's been on for more than 2 months. Battery is still in good condition after all these years I guess. :)
That still doesn't make any sense IMO.