You do have to keep the batteries from self-discharging somehow. If a Float voltage on shore power will be at too high a voltage, then all that usually means is they will gas more than is ideal, so you have to add water more often. Which raises the issue of which type of battery to get for that situation.
Wet Cell batts let you add water and see when you need to do that. AGMs don't. But people do have AGMs in hot places, so there must be a way to take proper care of them.
I don't know about living where it is hot, so over to the rest of the gang how to do that.