I have the 2015 Macbook 12" with 247 charge cycles. I've powered the laptop using Anker PowerCore+ 26800 and a USB-A to USB-C anker cable. I noticed the 'service battery' warning yesterday and I want to see if this issue was caused by the Anker battery. I am not sure if it has been there for a while. It is the first time I noticed the warning. I had the Anker battery connected to my laptop and an iphone 6s and I wonder if this could have caused damage. I want to make sure the Anker is not damaging the battery. I tried reset smc/pram several times but that did not do anything. I have applecare warranty. Do they replace battery same day or ship it out? Thanks.