Here’s a quick tip for you:
When using a laptop, so long as you have a healthy battery, it’s fine to use it without plugging it into the wall.
However, if you need to do something that will take a bit more power than basic applications such as installing software, installing updates, editing photos/ movies, or ripping/ burning a CD, I recommend that you plug your computer into an outlet.
When you run off of battery power, many computers will clock-down the processor. That means that your computer is jogging instead of running. Some computers might also clock-down the speed of your CD drive also.
Most of the time you can run on battery power alone, but if you need the extra juice, plug into the wall.