Answer to: Why is my MacBook battery swelling?I went to the local Apple Retail Store today with both my MacBook 13" and my MacBook 14" that I bought in November of 2009. Both of the machines have bulging batteries that are pushing out the back cover so that the machines do not sit on a flat surface properly. They said they could not replace the battery with a new one, but would be happy to sell me 2 new batteries. Since both machines are different models with bulging batteries, so much for the "once in a blue moon" claim! If it's so rare, why are both of my units suffering from the battle of the bulge!