I've got a mid-2012 13 inch MacBook Air that I've owned since new. Quite soon after I bought it, the drop-down menu that appears when I click the battery icon in the menu bar included the item "Service Battery". I never did anything about this, as although the battery seemed to drain more quickly than I would like, I'm usually close to a power outlet and use my MacBook while it's plugged in.
However, I thought I'd try to fix the "Service Battery" indication and see if I could get the battery running for longer. I reset the SMC, and when I rebooted the battery icon had a cross through it. I've seen this before on my MacBook, so I tried my luck and unplugged it. The screen went black, but when I plugged the MacBook back in it took me back to where I was, and the cross had disappeared from the battery icon. When I clicked on the icon, "Service Battery" had come back.
Do I really need to take my MacBook into Apple to get them to service the battery? Or is there anything I can do myself? I've attached a listing of all the data relating to the battery. Does anything look wrong?