Well I guess it's too late to mention this since you already bought something, but oh well.

If you want to get any sort of decent battery life out of any PC laptop, you need to get one with a Celeron-M, Pentium-M, or one of the several mobile variants of the Athlon.

The regular Celeron and Pentium 4 systems out there get maybe 2 hours of battery life tops, and their heavy power consumption makes the batteries lose their ability to hold a charge rather quickly.

I know this, because I have one.

Next time around I'll get something with an actual mobile processor.