Service Recommended Message

Check the condition of your Mac computer's battery - Apple Support

• Service Recommended: The battery's ability to hold charge is less than when it was new or it isn't functioning normally. You can safely continue to use your Mac but you should take it to an Apple Store or Apple-authorized service provider to get your battery evaluated.

Get it fixed: Mac Service and Repair - Official Apple Support

is this for your battery?

both my MacBook Airs state i need "service battery"

ignore that statement, mine are performing fine,

this is a new feature  staring using recently to boost up sales.

hopefully the next upgrade this will be eliminated or true were ones bad REALLY battery needs servicing.

just check the battery area and make sure there is no sigs of swelling or anything else periodically.

Please do take the message seriously and have the battery tested at an Apple store or authorized service center. None of us know if there is a problem or not and it could potentially result in damage to other components. Is the bottom of the computer a bit uneven?