Drove the Chevy today . . .

An older (gray haired gent who says he was a Chevrolet mechanic) at the coffee shop told me my "current draw on my battery" may be from my dash clock?  If it's parked for days on end - the battery gets drawn down to 11.5 volts or less.  I started un-hooking the ground, and now - no problem. 
Old guys rule.