I have an 8890, but I've found that I'm plugged in pretty much all the time...so batteries aren't an issue for me.
But, before I got it, I was concerned about battery life and ran into this neat device, the PowerPad. http://www.electrovaya.com/powerpad160.html
This is an external pad that you plug the laptop into and it delivers an extra 11AH of power.
Might want to check it out if you need more portability out of the beast