Please help- what is this box for?

[sfedeli3]

Hello all,
Since owning my 85PT40, I've wondered what the purpose of this
white box is in the basement of the bird. (please see photos link and
look at "What the heck is this" towards the end) It has no writing on
it and a large 2ga. 12V wire going to it. Thought that it might be an
iverter, but not sure. Does not appear to have any 110V wiring coming
out of the other side. Any help would be greatly appreciated.

Shane Fedeli
85PT40
Hershey, PA

55 degrees windy and sunny- October is here!