'Battery not detected' after temporary removal
I recently used the appropriate guide to remove the battery from my laptop while I was replacing the screen (as I read you should do this in a couple of places). With the screen replaced, I put the battery back in and re-connected everything. Now the screen works fine, but I get a ‘battery not detected’ status message, and if I remove the charger, the laptop immediately turns off.
What have I done to my laptop?