We own a 2013 converted MB Sprinter Leisure Travel Van SS 3500. The house bAtteries (2 golf cart deep cycle) are located in the engine compartment. Can these be easily swapped out for lithium batteries? I know the lithium are somewhat heat sensitive so placement here may be a problem. Our fridge is not hooked to propane, so our current batteries won't allow us to boondock for any length of time due to the draw from our fridge. The shorter, none slide out version of this conversion has propane fridge, but ours does not. Our style of camping is one that we would prefer not to always be dependent on shore power. Thanks for any suggestions.