If you have a obd2 reader and forscan (either on Android or a Windows based laptop) there is a great attribute which can be monitored, its called Battery State of Charge.
It seems that my car stops stop starting when the batter is displaying a SOC% of =< 65%, it tends to get this way after my short trip to work after a couple of weeks.
Anything higher and it works as desired. Saying that, I have never seen it hit 90% or higher. I'm pretty sure this attribute is a guesstimate, but it works for me!