RE: Cable to Connect External Solar Panels
If looking for rugged but very flexible cable to connect external solar
panels I can recommend this stuff:
<http://www.powerwerx.com/wire-cable/red-black-zip-cord.html>
I ordered a 25 ft roll of #10 for my panels, rulls back up on the original
spindle and stores very compact.  I also had the same in-the-ground #10 that
Frank used, from Arizona Wind and Power, and use a section of that from
where the wiring comes in through the back of the van and up to the
controller but it is much to stiff to be practical for deploying the panels,
much like Romex used in the house.  After finding out how nice the zip cord
was in the heavier gauge I ordered small rolls of smaller gauge zip cord and
have used it in a number of applications both in the van and for other
things, really nice and flexible stuff.