I installed SMCFanControl version 2.2 on my Macbook Pro 13inch I5 and I set the fan to 4000rpm. I can barely hear the fan so I am thinking about keeping this setting. One question I have is, is this software safe to use? Does running the fan at 3000 or 4000 rpm use a lot more battery than when it runs at 2000rpm by default? Thanks in advance for any answers.