You no longer have to live on the bleeding edge to see how well Opera's low power browser mode works on your own computer: the developer has released a finished version of its desktop web browser that incorporates the promised battery saver. As before, flicking the virtual switch tones down background tab activity, site rendering and video playback in the name of keeping your laptop alive for a little while longer. Opera is promising up to 50 percent more running time, though that's undoubtedly going to vary depending on your machine and your habits. However well it works, it's likely worth a try if your regular browser saps all the life out of your system.