How do I fix red X on battery icon?

I had somehow accidentally disconnected some of the battery charging function when I opened the tab up. When I plug the tab into the charger while tab is powered on, a red Xshows on tge battery icon, and the tablet charges extremely slower. I am using the tablets own charger and cable, and this issue happened right after I opened the tab up.

Where are the areas / parts that I might have accidentally knocked loose which may have disconnected half of the battery charging functions?