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Do you have a small digital multimeter for some testing? About $20 or so at most hardware stores and easy to use. We can do some testing here and track this down. Camping World is about the worst place to get anything fixed! Lots of complaints here on them.
If you can pick one up this is not that hard to track down. Otherwise we are kind of guessing at what it might be. You do need at least two batteries and 27 series would be much better than 24 series. Slides just won't work correctly with just one battery. Slides take a lot of power and will run one down quickly and then you have the problem like you are describing.
But we need to be sure that they are wired up correctly AND being properly charged.
Sometimes it is just that simple.........and a meter would show you that in minutes most of the time. Good job!