My battery barely lasts an hour while just web browsing with chrome (only a few tabs open, max 4). I went to apples site to try and find a replacement, and apparently they discontinued it. I tried OWC's NuPower battery and ultimately wasn't impressed by it's performance. The machine runs ML so maybe that OS is a battery hog (haven't done much research on power consumption between OS's). I'll buy another NuPower if enough people can vouch for it, but ultimately i'd like to see if anyone has any solid recommendations for me. Thanks in advance!