Hi sarah_rara, and welcome to the HP Forums!
I understand that you are having a problem getting the computer to boot up without the battery in. I will try my best to help you with this issue.
In this document for Computer Does Not Start and the LEDs Blink or the Computer Beeps it explains what the LED light means and explains what to do. I think this may be an issue with your AC Adapter so I am including this document for Using and Testing the AC Power Adapter for testing it.
I am also including this document for Battery Does not Power Notebook or Hold a Charge as it explains how to test and calibrate your battery, which should help with the charging issue.
I hope this information is useful. Let me know how it goes.
Good luck and have a great day!
