This is a battery that came with my laptop that I ordered from HP. It's a 6 Lithium-ion battery. Unfortunately it did not provide my laptop with much power. For the first few months I used it, I found that it took about half an hour to charge and lasted for an hour at a time, if I was lucky. So I ended up just having the charger in at all times, even though I knew that would kill the battery some. The battery really doesn't last long. There is no way I'm going to be able to go on the plane or in a cafe and use it in public. Eventually, I got so fed up with the battery that I just took it out and I've just had the cord in ever since. At least since then my laptop does not turn on in the middle of the night and wake me up as well as drain the battery! Hurray, the battery isn't even needed! Boo, it was a waste of my money!
I really don't think you'll ever need the battery unless you go out or are traveling in a car or on a plane. If you're in a building, just have the laptop plugged in. It's easier on the battery if you take it out and you won't have to worry about charging it over and over. Just don't let anyone touch that cord!