HAving done engineering work on that topic..
The RV batteries are designed for longer current discharge, not like automotive batteries designed for short bursts of high current.
Theyre also called golf cart batteries.
Yuasa engineering told me this:
1. NEVER discharge below 10.6 V or permanent damage
2. about 14.8v max float voltage
3. There is a max discharge rating, but I forget what it was and itll vary with brands and battery condition
4. use a conditioning charger to extend the battery life.
And, only fill it to the top of the plates, higher electrolyte levels increase self discharge.
The critical factor in Ham radio is that the average duty cycle of a TX is about 20%, SSB or, surprisingly, CW also.