If your laptop is usually run on the mains, I believe that best practice for prolonging your battery's life as as follows:
Fully charge the battery and remove from the laptop.
If it's unused, then about once a month put it into the omputer and run on battery power until it's completely flat. Then charge it right up and remove from the computer.
On occasions when you do have to use the battery, always try to run it right down, then charge it right up.