I think I have mentioned this in years past, but  a handy auxillary
fuse panel for our vans can be found on 2000 or so and newer new
beetles and golf/jettas. Its a small hinged lid box with a thickish
gage wire that attached to the donor car battery. Inside are 4
fusible links (2 X 110 A, and 2 X 80 A , amperage figures from
memory) and 3 spade type fuses. It would probably be panel enough for
camper accessories.

I have been procrastinating in workshop and took a couple of pics of
it, see here;

http://shufti.wordpress.com/2010/04/06/aux-fuse-panel/

alistair