What advice for running hp laptop without the battery installed?

Answer 1

When a laptop battery stops working you can continue to use the laptop plugged in to a wall outlet. It probably does not matter if the battery is still attached to the laptop, or not. You will have to treat the machine the same as a desktop.

You do have to remember that the laptop should not be unplugged from the wall outlet without first turning it off or putting it into hibernate, or sleep, or suspend, depending on what system you are using. If you just unplug it, you will lose your work and you may mess up the file system or harm the system software. If this happens, the next time it is turned on, you may have to (or be forced to) run some sort of disk check for errors, if you are lucky. It is also possible that the system will not boot successfully.