What is wrong with my Dell Inspiron?

I am having some issues with my Dell Inspiron laptop. Last week sometime, my computer stopped charging. The computer detected that it was plugged in, but the charge status was "Plugged In, Not Charging." I checked, and the battery was supposedly in working order. Then a few days ago, I was online and my computer just instantaneously shut off. I was able to reboot it with no problems. It did this a few more times. Now, my computer will only stay on for around a minute before it shuts down on its on. What's my issue?