You can find it at night only
At the battle tower thats where I found one
You can find basically all of them in mt. Coronet
I find them in mount cornet hope that helps
In Mt. Coronet or Turnback cave is where I'd go to find a good golbat
I found one in orebourge gate at lvl 10 hope helps
I found a Golbat at the top of the Lost Tower in route 209 below solaceon town^^hope it helps^^