Just my .02 but if I were you, I would seriously consider the switch to Lithium. If you are boondocking 9 days at a time then lithium will give you much better performance in all aspects. They are lighter, last longer, charge faster and you can pack more power into a fixed amount of space. The Elite 2 battery tray can fit 2 of the Epoch 300ah batteries which would give you plenty of power for long boondocking adventures.
John