I have an early 2011 15" MBP - 2.0gHz with an SSD - which has been a beautifully-performing machine until I installed Mavericks. Now I have the "Service Battery" warning. Resetting the SMC and PRAM has had no effect. Attempts to calibrate the battery take it in the wrong direction ... I'm down to 39% of rated capacity after my fourth attempt to calibrate. When I started, I was at 68%. I've been tracking with Coconut but have yet to save the data ... you'll have to take my word for the numbers. I read the corresponding Apple discussions and wonder whether this is a purely software issue ... I have ordered a replacement battery, but I note that I did not have any battery issues before I installed Mavericks and now I'm pretty far along the path to having no battery at all. This is maddening, to say the least. Any ideas?