Also, something else to consider related to battery life. A laptop battery will lose it's full capacity over the life of the battery/laptop and are rated at their ideal conditions. For example, in 12-18 months, a 4 hour rated battery under ideal conditions may end up lasting 2.5-3 hours in reality and under normal conditions.
I'm fully expecting the same with the battery in the 1000HE which is currently rated at 9 hours with all power saving features on. In 2 years, if I still get 6 hours out of the battery, I will still be happy.
If you want more information about proper use, care, and maintenance of laptop batteries, you can go here:
http://batteryuniversity.com/