How Can I Tell If I Need To Replace The Battery On My Mac?
In Mavericks, move your cursor to the menu bar and hold down the Option key while clicking on the Battery icon. The top item in the menu will show the condition of your battery. If will say either "Normal", "Replace Soon", "Replace Now", or "Service Battery". If it says either of the latter two options, we recommend making an appointment at the Genius Bar of your local Apple Store.