Auxillary Battery Malfunction

  mercedes/c-class/2015-____

2015 C300.  I was away for 15 days and did not use the car.  Upon first use, Auxiliary Battery Malfunction came on red, after driving a few minutes, continued to flash every couple minutes in Gray.  This pattern continued for a few uses (short trips), and has now stopped, after I drove a bit of a distance.  

Should I be worried?

 

16