I'd like something with decent performance, but battery life is my main
focus. Six hours or more per charge would be preferable. I can't plug in on
the train.
see if you can get a deal on a spare battery when you buy the notebook. Even
if you find one that is good for 6 hours it's charged time will decrease if
you are going to use it every day. Ask the Dell Rep to give you a discount
on battery #2
To my knowledge, no one battery will do that but of course you can
swap out batteries to do that. That's probably the easiest thing to
do but save your work in between. Whatever you choose, use the power
saving settings to prolong life of battery. And be aware that as you
use the battery over time, it's usefulness (charged time) will
diminish. And when home, try to take the battery out of the laptop to
prolong it's life and just plug it in.
Just to add...you hear many recommendations (stories/tips) about
charging and discharging batteries to prolong their life. Your lithium
battery has a given number of charge/cycles, whether 500, 750, or
1000. If you partially discharge it (say 20%) and charge at that
point...it counts for a cycle. So you lose the 80% you could have used
in that cycle.
I also believe that you shouldn't drain it to nil.
You would have thought at this point that technology would have come-
up with a more perfect battery! Low consumption, front lit display,
backed-up with solar charging.