Ann, unfortunately, the battery
is something that wears out and can be replaced with what ever the owner feels like. I have bought a Trillium
that someone put the battery under the dinette seat, and another that had a group 27 battery that they built a bracket that allowed them to seat it, length wise, inside the V of the tongue so that it was flush with the bottom of the square tubes. A group 24 battery is most common in my limited experience.
Do you know where on the trailer the battery is? Any pictures of it?