Thank You Roger, you mentioned the primary causes of battery hydrogen explosions, overcharging and removing clamps when the charger is on and causing a spark. I saw the same thing happen when I was 15 years old and started working in a gas station and a mechanic put a high boost charge on a 6 volt battery and pulled the clamps off under load. Funny thing, I haven't seen one explode since.
A properly installed and vented battery (Hear that Parkliner
?) poses no safety threat when placed inside the coach.
BTW: When I move a battery inside I intentionally place it as close as possible to being over the axle
to give me more control over tongue weight
And... some RV storage lots specifically suggest removing batteries that are tongue mounted and store them inside the coach for security.