It has been five years since we did a benchmark of the various web browsers and their effect on battery life, and a lot has changed. Our testing then included Opera 9 & 10, Chrome 2, Firefox 3.5.2, Safari 4, and IE8. Just looking at those version numbers is nostalgic. Not only have the browsers gone through many revisions since then, but computer hardware and the Windows operating system are very different. While there has been a lot of talk, there hasn't been a lot of data comparing browser battery usage. Today we're going to put the latest browsers to the test and deliver some concrete numbers.