Hi My Macbook 12" 2015 battery is at 43.6% design capacity(2296mah out of 5297 mah) after 320 cycles. Battery manufacture date is May 5, 2015 and laptop was made on June 8, 2016. I have periodic issues with charging the battery to full and OS Sierra says I should "SERVICE BATTERY". Earlier today it could not charge past 75% and was showing battery drain even with the charger plugged in. I still have about 7 months on Applecare and would like to know if I need to wipe all my personal data(Filevault is on) before handing it over to Apple. Does Apple need to have access to the OS for the repair? and for those who have had the battery replaced, do you know if the battery replacement will be covered as this seems to be premature wear. My macbook 13" 2011 still has about 80% battery capacity. I am setting up a genius appointment for this Thursday and would like to be prepared before arriving. Thanks.