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Originally Posted by jubei
I just realized the univolt system is missing as well. Is it possible to run the system of a battery charger with a brain attached to a deepcycle battery.
I agree that what you propose as a short term
solution is quite workable, but with one caution. You mention that the previous owner removed the battery compartment boxes, and that does bring up an issue with where you mount the battery unless it happens to be an AGM battery. With a lead acid battery, venting is critical and particularly so in an enclosed RV. One of the reasons that I switched to AGM batteries in my '64 Overlander was the fact that modern Deep Cycle Marine batteries that I can find where I live were not compatible with the '64 Airstream method of venting. The battery wasn't well isolated from the interior so the smell of battery off-gassing was immediately apparent. As an interim solution, you might want to consider temporarily locating a standard lead acid battery in a battery box on the hitch and running its cables either through the existing battery door or through an open window when the coach is in use. The best alternative may be to install a new battery box as you will eventually need a permanent home for your coach's battery.
Good luck with your project!