dc to dc charger wireing

[Turd Furgeson]

i am gathering the stuff to do the dc to dc charger.
i can pass a fish tape from the battery compartment under the insulation up to the pin box just to the right of the under deck light.

how should i get these wires thru to the pin box or thru the fiberglass lid?
a am thinking a 1" hole and grommet just to the right of the light on the lid.

any idea's or help would be appreciated.
pix too if you have em.