[red-beard]

First, you want LiFePo4, Lithium Iron Phosphate batteries. You can run then ~3,000 full cycles or about 10,000 partial (60%) cycles.

We built a system for RVs we called it the Mi-Grid 500. It included 2kW of solar for the roof, ~7.2 kWh of energy storage and a backup generator. The generators we supplied were automatic start, so if batteries went low, the generator would kick in and charge to about 80% (about 1 hour, depending on your power consumption) and then auto shutoff. 2 kWh of solar will produce 8-12 kWh of energy, depending on your location. The inverter is 4kW which will run your RV Air Conditioner, microwave oven and a hair dryer, all at the same time.

On building your own battery bank, you need to understand how to properly apply a BMS (Battery Management System) to prevent runaway. The batteries we used had the BMS built in.

The latest version of our system used 2 x 12V 300AH batteries.

And the system was compatible with RV shore power. It would also charge the batteries back up while on shore power. And everything we supplied was UL for safety.

I'm not really in the business right now...