The Magnum in the Tuscany flows through so usually the inverter is shut off unless were in the process of loading or unloading the fridge.
I like the inverter to be the backup if the fridge is full and power goes out for any reason, so battery bank is on during those times.
Sealed batteries will tend to last as long in use as on the shelf, properly maintained, so it is a wash.
Having to add water is a different story
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