Batteries
My engine batteries are located in the compartment just ahead of the electric cord (on an electric reel). There is an electrical outlet in the reel compartment, used to plug in the engine heater.
I drilled a 1" hole through the compartments, and ran a Battery-Minder line through to the engine batteries. The connection is permanent. I plugged the Battery-Minder (velcro holds it in place) into the electrical outlet.
Now, whenever I'm plugged into shore power, the Battery-Minder is charging, desulfanating, and keeping my engine batteries fresh.
I also change all batteries (except the two engine) to Optimas. Yes, the 4 six volt on the inverter are now 4 twelve volt blue top Optimas. The coach batteries are yellow top.
I also put a charge wizard on my converter.
My previous days of having to clean acid off my coach batteries weekly are now over. The battery compartment required a complete cleaning and repainting, but overall it is worth it.
Safe Travels.
Rick