Hi Oluwabunmie,
Thank you for your reply.
I see you have ruled out the battery, by trying two others, with the same result.
Here is a link to Battery Does not Power Notebook or Hold a Charge.
If this has not resolved the issue, I suggest contacting HP support for further assistance.
Please call HP technical support at 800-474-6836. If you live outside the US/Canada Region, please click the link below to get the support number for your region HP Technical Support Sitemap.