Our house batteries are gone...can I open the slide out without them ?

Back in Feb '22 our catalytic converter was stolen (cut away from our) '08 Itasca Cambria. We have been waiting since then for a replacement which was ordered by a Ford Dealer. We are in southern California. We are told that these converters are hard to get as the theft and black market of them is rampant.
Does anybody have any experience or ideas as to getting one ?
Thankyou.