Short answer is YES. The slides may need more power than the converter can convert.. in fact I have seen this in real life. Was ask to help move an RV from a site to storage by park management.. The house (And chassis as well) batteries were .. Well. FLAT. I mean Completely gone. We dropped in a new chassis battery (Well the Landlord bought it and I installed it) but not the house. We put 3 people on the slide. Myself and another fairly strong park employee pushing and the camp host pushing the button and got it in..
Workhorse 8.1L vortec, been sitting for years.. Fired up and ran like it was brand new.. I drove it to storage and .. from there the former owner's family claimed it.
