You would think that a camper that new would have a better charger that does not boil the battery to death.
Some people mentioned "poor maintenance" if you have a good charger there would be no maintenance required. Sure doing good maintenance might make the difference between a battery lasting 5 years or 7. But, not 3. Something is wrong if you need a new battery every 3 years.
We have dozens of battery's on the farm and we never check the water on them in this day and age. They last for years. Sometimes even a decade.
It could be that RV manufactures are not putting that good of chargers in their RV's yet though.