Laptops are currently outselling desktops, which means a couple of things. It means that users are more mobile, and are using applications while they sit in conference rooms, coffee shops, or airline seats. This also means that for a good percentage of the day, you can be away from the wall outlet that gives life to your laptop. I often find that I’m consciously aware of what I run when I’m on a long flight, because I want the battery to last it all the way to my destination. However, my choice of application usage is based on in intuition and environmental clues. For example, if the fan’s running, and the performance of applications is “chunky”, then I know that I’m loading the system down, and the battery is bleeding dry faster than I would like. However, I wanted something a little more scientific than just laying my hands on the machine, and trying to feel the force of the current flowing. There are some really sophisticated pieces of software that will examine the power usage of various applications, but I figured by just monitoring a few key performance counters, I could have a pretty good approximation of the drain rate.