My averatec 1150-EH1 gets the same 2.5-3 hours but runs cooler and faster. My Lenovo x200 gets 9 hours with xp pro, 6 with Vista 64-bit and 5 hours with ubuntu 32 or 64-bit.
Ehh, something is wrong with that. 3 hour difference?
I also question how the averatec can be running cooler under Linux if the battery life is still the same. If it is using the same amount of power, it is dissipating the same amount of heat. Period.
I suppose the balance of power usage may shift (e.g. more power being dissipated in the screen versus the CPU) due to differences in power management strategies, giving the impression that it is running cooler. But that's probably a bit of a stretch.
Or perhaps Linux is simply getting the estimated battery life wrong, and telling you the battery is discharged when you've actually still got some life left.