My MBP (2011) has been working perfectly the whole time I have had it. I use it for music and had to use it on battery a few times when I forgot the power cord on gigs. I've left it plugged in most of the time and just recently I had it unplugged and the battery indicator gave me the service battery message. I installed more RAM and a new hybrid SSD hard drive and did a clean install of Mavericks. Ever since, the service battery message is gone. Is it possible that there is nothing wrong with my battery? As I type this, it is unplugged and has almost 5 hours remaining according to the icon. I find it odd that before the upgrade I had the batter issue and now the message is not showing up. Is it possible that is was an OS glitch or even using it unplugged and plugging it back in ironed out the problem? I intend to make this my main Mac and sell my iMac so i want to make sure it is working correctly. It's really fast now with double the RAM and the 1TB SSD hybrid drive. Is there another way to test the battery rather than just look at the titlebar icon?