My late '08 MacBook has been showing 84% health in iStat Pro about 95% of the time. The past few days it's shown "Service Battery" for a few minutes, but then it cuts off. It just said that for me, and it shows 78% health in iStat Pro. Could it have something to do with me using an 85W charger today instead of my 60W? (I left mine at home and borrowed someone's at my school) If I need to replace my battery soon, I have one question. Are the Anker batteries that are on Amazon decent enough to use? ---------- Now iStat Pro shows 56% health. This battery only has 54 charge cycles on it (original battery, this MacBook wasn't used much at all by previous owner) ---------- OK what the heck... I unplugged the Magsafe and plugged it back in, the warning went away and 78% health shows again.