Will adding ram to my MacBook Pro affect battery life? Is so how much? I don't want to lose more than 30 mins. I was going to put 2 4Gb crucial sticks in.
Nope, you'll get generally the same battery life. You actually might get a few seconds by saving the energy from starting up the HD and writing files to that, as that's what happens when the RAM is full... depending on what you're doing.