Why is my converter is cooking my battery?

I recently checked my RV battery and found it to be pretty much bone dry. The converter (Progressive Technologies) light had been indicating everything to be normal up to this point. I topped the battery off with water and hooked it back up to see if I could manage to get any life out of it. The lights went thru the normal boost, then regular charge and then to trickle over the course of about a day. I checked the water level again today and found one cell dry and the battery was quite warm. I topped the one cell off again and reconnected. The converter went to boost charge (approx. 14 volts)the battery again got quite warm (hot actually). I even checked the line voltage at the cables with the battery unhooked because I thought I may have reconnected it wrong. (One heavy gauge white and one light gauge black to -Neg and one heavy gauge red and one light gauge red to +Pos) Would a shorted battery be doing this?