Pull-out roller bearing trays are not cheap. I had to install a sailboat-like floor panel in my bus so I could pull it up and then lay on the floor to check my L-16 batteries. It isn't fun. So I purchased 12 recombinant battery cell caps which helped a lot but are $$$
Try this
Remove and shine-up battery cable terminals and battery posts
Use felt rings which are like washers over the posts.
Silicone dielectric grease. Rub it into the washers both sides
Then encase top bottom and sides of battery terminals with the grease. It will last many years.