In the top right corner of the Carbonite map (either size, minimized or maximized) there are two small boxes. Right click the farthest rightt one and make sure the "Hide in combat" option is not checked in the menu. As far as I know, that's the only place that option can be changed or set. (Of course, I could be wrong and I'm quite sure that if I am, someone will jump in here and correct me.
)
That option
should be able to be set (in the same way) for each Carbonite map size individually.