Laptop only turns on with power supply

Registration date
Sunday June 25, 2017
Last seen
June 25, 2017
I am using Acer Aspire E14. Recently, when I unplug the laptop from power supply and press then ON button the laptop isn't starting up. When I plug the power supply to the laptop and press the ON button, the laptop starts up. Why? What am I suppose to do? I tried to follow some steps to solve this problem, but unfortunately I can't remove my battery. It's fully closed. What should I do? Is my battery faulty?