Tesla powerwall?

"Maintain my $30,000 battery bank? Sure; I have people that do that for me"

Lots of boaters are successfully using Lifepo4 prismatic cells, but it is not a drop in lead acid replacement.

http://www.pbase.com/mainecruising/lifepo4_on_boats

A couple RVers are doing it too, but one should have automatic high and low voltage disconnects to prevent battery damage. One over charge or over discharge can destroy them.

Also one needs to retrain their brain away from lead acid maintenance procedures. It is better to not fully charge them unless one needs their full capacity that night.
Better to cycle them from 20 to 80% than from 50% to 100%

Trouble with Powerwall for an RV is that it runs at 300 to 400 volts. Unless you plan to utilize 2 kW solar and run your air conditioner off-grid I doubt the size and complexity would be worth it.

Plenty of 12v to 48v lithium batteries available to more easily mange the power in a smaller RV situation.

http://www.lithiumion-batteries.com/products/24-volt-lithium-batteries/sb24300.php

No, and no, they are not a good "fit" for an rv. The same amount of storage can be had for a lot less using AGM or flooded jars for 1/10 the price of the power wall, and that is NOT including the rather expensive inverter the power wall requires.