If your Mac battery runs out of charge quickly
If the battery in your portable Mac runs out of charge more quickly than you expected, check your battery’s condition.
Hold down the Option key and click the battery icon in the menu bar of your Mac.
You will see one of the following conditions:
Normal: The battery is functioning normally.
Replace Soon: The battery is functioning normally but holds less charge than it did when it was new.
Replace Now: The battery is functioning normally but holds significantly less charge than it could when it was new. You can continue to use your battery until you replace it without harming your Mac.
Service Battery: Your battery is not functioning normally; you should have your Mac serviced. Take your Mac to your local Apple Store or contact AppleCare. See Find how to service or repair your Mac.