I used to get about 10 hours of battery life from my IBM ThinkPad 240X [1] running Windows 2000 way back in 1999. I did this by using the extended battery (whi

I used to get about 10 hours of battery life from my IBM ThinkPad 240X [1] running Windows 2000 way back in 1999. I did this by using the extended battery (which stuck out from the back), and by buying two of them. On long trips, I just swapped the batteries. [1} Ultra-portable model with no floppy drive and no CD-ROM, but a wonderful IBM keyboard.