Everytime I unplug my computer, it immediately powers off. However, when I check my battery strength, it says 100%. I'm sure there's an easy explanation/solution for this, but this brother of Lil Pun has no idea.
I'm assuming this is a laptop. What brand is it? I've seen Dell laptops that will only work when plugged into an external power source, and it turned out to be an issue with the motherboard.
I'm not totally sure, but maybe check the power savings options to see if something is checked to power down the computer when unplugged.
See, if I knew where that was... I'm much worse than Lil Pun when it comes to computer stuff, however, I'm lucky to normally have access to someone who knows how to fix all this stuff.
I've seen this in the past and it always turned out to be defective system board. One thing that I try to remind my wife is to make sure she doesn't block the ventilation. Over time, it can degrade the components until something like this happens. Just a thought.