Hi paulbayly,
Welcome to the HP Forums!
I would like to take a moment and thank you for using the forum, it is a great place to find answers. For you to have the best experience in the HP forum, I would like to direct your attention to the HP Forums Guide First Time Here? Learn How to Post and More.
I understand you have replaced the battery and the AC adapter. The adapter is working but you are unable to use battery power. Here is a link to Battery Does not Power Notebook or Hold a Charge.
If you would like additional assistance, would you please provide the exact model of HP computer you have and the Operating System you are running. How Do I Find My Model Number or Product Number?