1.Brightness: how low can you go? Without any question, the fastest way to suck the life out of a battery is leaving your brightness high. Turn it down as low as you possibly can without needing to up your glasses prescription. On my Vaio, I can select from one of 8 levels. During one test, at brightness level 3 my system reported 60% full, with 3:52 (all times are hours:minutes) of life to go. I switched up to level 5 and in 17 minutes of use, I was down to 52% full, with 3:06 to go. In other w…