Just bought myself a new laptop - and not sure what kind of battery life I should expect - what is considered to be "normal" battery life and what things can I do to extend battery life? Curious to hear what other laptop users have dealt with.
My experience: it depends. When I work on excel, word, powerpoint or surf the internet I can get somewhere close to 3 hours of battery life (good enough to watch a whole movie on a plane!). However, if I attempt to burn a CD the battery eats up the power really fast (no more than an hour).
You can buy a 6 hr battery (don't know how much burning takes from it) for $150, at least that's how much my sister's cost and it lasts double the time, from 3 to 6, although, this battery is a tad bigger.
Basically devices like disk drives, etc. high CPU and/or memory usage will have an effect on battery time. Unpowered USB devices (memory sticks)? I have one of those Compaq laptops with the non-mobile Duron CPU's (one of the infamous lap scalders) and I was able to do three or so hours of coding on a charge. It also depends on the laptop. Some are better at battery life than others (read reviews).
As a veteran of the DEC (cum Compaq) notebook team, I'll echo this comment. Using your screen at a lower brightness may increase battery life as much as 50%. Look for a lower power setting (we called it "passive" cooling) that cuts CPU speed to run the system cooler rather than using the fan (aka "active" cooling) since the fan will use power.
My laptop, A Dell Inspiron, has a feature to automatically set the power-saving settings on when you unplug it, and etc. Also one thing to note, you probably already knew this, though, is that a desktop replacement will have much less battery length than a true portable in most cases.