New Fiver - slides and jacks use - w/o killing battery

Assuming it's a mechanical slide, find where you can hand crank it in and out and where the crank handle is (those often disappear after not being used for years).

It's a pain but a dead battery becomes a nuisance issue if you can operate manually.

A fully charged battery should handle several times in and out or as others have suggested, just plug in with the truck running.