[QUOTE][/The difference is that they CAN be run down to 20% state of charge.
Redo the math with 20% instead of 50%.
Your batteries have 210 Ah usable.
This one has 466 AH usable.QUOTE]
Actually, AGMs can readily tolerate discharge down to 35-40%. I'll grant that lithium-ion batteries are even better, but that comes at a price.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL