Hi,
I suspect that the battery charge voltage was way to high, and may cause any kind of damage. Melting holes into the bottom of the battery might also happen. Without water, then rupture can happen too.
So after replacing the battery, consider checking out the shore power charging system, and see what else is wrong with it. If it is charging at more than 14 volts, that is the problem. Perhaps one of the batteries is connected backwards? Applying +12 volts to the negative terminal can also cause problems.
Is the RV plugged into 120 volts or 220 volts? Perhaps the charger is not getting 120 volts and be the root cause of the problem?
What year is the RV?
What model number is the charger or converter?
This will help someone help solve your problem.
Fred.