There are companies out there that make replacement batteries for all sorts of laptops. but they will Void your HP warranty.

The battery dissipating that much in only 18 months? That is unusual and may be something wrong with the computer. i would turn it in to HP if possible.

Thank you for your reply, jermaghs07

Unfortunately, my HP warranty has expired. I have heard that normal battery life is around 12-18 months after which you would need to get a new one. Isn't that true?

no, i own or have own 3-5 yr old laptops with the original battery ,still holding charge for up to 2 hrs

Yea. I have had laptops that the battery lasts like caperjack said almost 5 years.

I would buy a replacement battery and use it for a while, if after 18 months it does the same thing you might want to take your computer to a tech and let them check it over and see if there is anything wrong.

When buying a new battery, remember the more cells the better.