Yesterday I went in for an oil change at my dealer, and they told me that my battery post is cracked. I have had no problems with the battery - is this something that needs immediate attention and is it as simple as a new battery?
If it is in fact cracked, the connection will likely begin to corrode and you’ll begin to have starting problems. And yes, the only repair will be a new battery.
What he may have meant, is that the post is loose as it comes out of the battery case. If this is the situation, the top or side will have a gap around the post that will allow acid to migrate out. That will corrode the battery clamp and allow acid to get into the battery tray and its supports which does wonders to metal. If the post is loose get the battery replaced as soon as you can.