When I bought this trailer here, it did not come with a battery. I bought a cheap deep cycle from the big box mart and it is almost burned up. I expected it to last a year and it exceeded that. When I...
Most farm tractors from the 1960s and earlier had exposed batteries. Our 1978 Nomad TT had an exposed battery until I built a new frame to hold two batteries and added battery boxes mostly to make it harder to steal the batteries.
Older batteries probably held up to the elements better, the materials used for batteries these days I'm not so sure about. I would use a cover of some sort.