Battery issue

[PinkhulaSkirts]

I have an HP Envy Notebook (product number: W2K91UA). I have had this computer for about 2 1/2 years in which I have used mostly for school work. I keep my laptop plugged into the outlet the majority of the time. In the last 6 months I realized that I could not take my laptop off the plug in charger without it dying within 5 minutes (no warning, the computer would just shut off). A few weeks ago, I realized that my battery was down to 33% plugged in but not charging. I searched for some answers and found one that said to uninstall the battery driver and it would fix the problem. I did this and initially it still said 33% and then about 20 minutes later the batter said it was 100% plugged in but again not charging. Over the last few weeks, my battery will go from anywhere from 99% down to 22% (which is what it is at now and has been for the last two days). It will always say plugged in (because it is) but it never says that it's charging (even though it's plugged into a working outlet). I did the battery check using the HP Support assistant and it says, "The battery is functioning correctly but due to normal aging of the battery, the battery life between charges has reached a point where your battery is no longer useful." So I am thinking I need a new battery. I have been having a hard time finding a battery through HP's website so I decided to purchase one from Amazon. In looking for my battery to see if the battery I was going to purchase was the same size I realized that there is no battery pack on the outside of the computer like there used to be. My question is where is the battery located? How do I purchase a new battery and install it? And if my computer stays plugged in will my computer continue to work regardless of the battery not charging? I do not want a new computer because besides the battery issue my computer is in good condition. Please advise. Thank you in advance. I should also mention that my computer is not under warranty.

[WAWood]

@PinkhulaSkirts 

The battery pack has not been outside the PC; you are confusing that with the charger.  In older laptops, the batteries could easily be removed from the case by moving a slider, and when those weren't available, opening a panel.

In the newer PCs, the are are no sliders or panels and the case has to be opened, in some cases PRIED OPEN, in order to remove the batteries and some of them are glued into the PC and not removable.

If your case does not open easily by removing screws, you can damage it severely by trying to pry it open.  You would need to take the laptop to a local laptop repair facility where they can open it and check to see if your model battery is removable.