this type of box might serve a good use for trailers with exposed hitch-mounted battery placement - though I think most RVs with battery boxes under or within the RVs storage areas or steps are already designed for the batteries and don't need additional 'cover'. Batteries actually 'want' air flow - it's better for them.
'14 Palazzo 33.3 bunkhouse 34' diesel
KingTailgater2 Dish HD, 100w/5a SOLAR, BlueOx
100,000+mi since '14 - US, Alaska, Canada.... formerly Georgia, then NorthCarolina, now Alabama : )