Same issue!! After I upgraded OS to version 11.1, the battery status changed to Service Recommended. The other strange thing is when the macbook is woken up, a red battery standing for recharging is presented on screen, and it cannot be woken up. However, after I connect it to power adaptor to wake it up successfully, the battery will show above 70%. I went to Apple service today. The staff told me that the battery shall be replaced, and the cost should be paid. Because the battery is only one year of warranty time. Mine is bought last Sep. So frustrated on Apple.