Lead acid batteries must be located where they are vented. This usually means outside the living space of the motorhome. You could use a storage compartment, but make sure it's robust enough to hold the weight of the batteries, and it has a positive airflow to vent off-gassing to outside.
Lithium batteries are a different story. They can be placed just about anywhere INSIDE the motorhome. They can also be installed in any orientation... on their side, etc.
So... type of batteries will make a difference where you plan on installing them.
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