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.
To piggy-back also make sure that your MBP can handle certain mhz's. I know I got the 1600mhz and it works fine, I heard 1800 doesn't, not sure tho.
No. Any compatible RAM (204-pin SO-DIMM) should be designed for the same or lower voltage, otherwise it wouldn't even work.
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. (right?)