I have a 2011 MBP 17 with AppleCare good through May of next year and my battery came up as "Service Battery" and at the genius bar, it failed the battery test, despite the battery being just 205 cycles into its 1000 cycle lifecycle. The battery had also been draining ridiculously fast the last few months, I had been chalking it up to the fact that I run my computer with higher than normal settings even on battery mode. The genius quoted me $179 for the battery replacement fee and claimed that no warranty, not even AppleCare covered batteries because it was a consumable part. It was a good thing that I knew the difference between "wear and tear" and "defective" because I brought up the point that the battery was "defective" because it should not be failing barely 20% into its lifecycle. I agreed with her that "wear and tear" would not be covered anywhere, but I had to point out adamantly that the battery was defective and defective batteries are indeed covered under AppleCare. I then asked her to go check with someone (while I pulled up the AppleCare terms and conditions) and she came back to me 5 minutes later and said they'd cover the battery problem. They didn't have the battery part in stock, and told me to come back the next day, but at least they got my service ticket in the system. Came back the next day to do a quick swap out and I am not sitting happy with a brand new battery (and I guess the repair person fixed my trackpad's sticking problem, which I didn't even bring up). So why do Geniuses try to pull a fast one and convince us to pay for a defective battery replacement? I'm sure if it was someone less savvy about computers, they'd have just paid it. On another note, I did have this laptop docked in clamshell mode to a Thunderbolt Display for several months on end, would that have hurt the battery in that it never got a chance to discharge?