Chosen Solution
Was attempting to remove my MacBook battery. Was unscrewing when hand slipped and removed a little cable, where does this go??
The flat cable next to battery connector goes to the battery indicator you have on the side of the Mac. Unless it was snapped broken it plugs to the small connector beside that one of the battery. You can see where it fits at step 14 of this guide: MacBook Pro 13" Unibody Mid 2012 Logic Board Replacement
I couldn‘t find the fpc 6 pin connector with 0,5 mm grid. However I managed to connect the flex cable directly on the mother board with 0,3 mm isolation filament! It was tough but I‘m so happy that it works again :)
