In recent years web browsing has become a rather CPU intensive task. The javascript used for scrolling menus, Flash based ads and other (usually) unnecessary junk running behind the scenes on certain websites, can put your CPU to the test. Of course, whenever your CPU spikes it has to pull more energy which produces more heat which, for laptop users, can drain the battery much quicker than if this stuff was not running.

You can help prevent this by taking advantage of a script blocker, such as Firefox’s NoScript add-on.

SecTheory.com took a notebook PC, a couple of browsers and measured the battery drain on the Top 100 Alexa sites. They then took the worst offenders, that is, the ones that took the most power drain, and blocked script and ads using NoScript and AdBlock Plus. The results were quite significant. On a Dell Inspiron B130 notebook, with a 1.5GHz Celeron M processor and 1 Gig of ram, running fully patched Windows XP SP2, the power consumption when browsing the worst offending sites dropped by 11W, a 20% reduction.

These are pretty impressive results. Granted, it does take a bit of time for your white list to get caught up to where you don’t even notice a script blocker is running, but investing a little time can really impact battery life if you do a lot of browsing… especially on ‘intensive’ sites.

One of the improvements you can expect to see in the latest OS release by both Microsoft and Apple is a noticeable increase in battery life. By some estimates, Windows 7 will boost battery life by 11% and Apple’s Snow Leopard by 10%. These are accomplished through, among other things, more efficient handling of idle CPU time and better management of wireless radios.

Even if these numbers are off by a few percentage points, I would consider anything around 8% to be noticeable as you are getting an ‘extra’ 5 minutes on each hour. Of course battery life estimates are highly subjective because they depend on what the user is running, but for the most part many users will (hopefully) realize this difference.

Just something to keep in mind if you are in the market for a laptop or you already have one capable of running the new OS releases.