Hi Terry

I think it is a pretty sure thing that the battery got it's name from Robert H Cobb, son of Robert Livingston Cobb. In his obituary he is stated as the son of Robert L Cobb. Also several Cofederate Veteran articles say that too.
His cousin Robert Linah Cobb served in the battery from shortly after his escape from Ft Donelson until he was wounded at Shiloh. He was then transferred to the Engineers.
It was Robert Linah Cobb's sister Irene who married Frank Patton Gracey who was 1st Lt. then Captain of Cobb's Battery after Robert Cobb was promoted after Chickamauga.
Todd