i run 6mm for the fridge and lights.
ive updated the lights and now run leds.........awesome!!
low amp draw and super bright, yet to replace the main fluro.. utilux..
boat bias are great to deal with and well priced, great lights too.
with the dual battery, if the second battery is further away run a thicker cable.
ive run the matson kit in mine and mates car.
very easy to fit, just upgrade the screws into the firewall, to stainless, they bite harder and hold better.
avoid autobarn on the kit.. WAY OVERPRICED....like a 100 just on the kit.
do the ring around, usualy the local auto shop
will be better priced than autobarn or repco.
use good quality fuses waterproof, and buy some silicon spray, and spray the inside of the fuses, that helps with corrosion.
support your local auto shop they will be cheaper than repco, autobarn, and better service, just make sure you get everything as they are open less than the other two, and get caught out on sunday putting stuff in.
get good quality thick round washer looking terminals, they will handle the heat better and not warp.
its easy stuff to do..
only relays and stuff is the hard part like with driving lights, but theirs enough threads on here, to do it yourself.
nothing better than working on your car, and wiring up lights, and to see it work, with switches involved
awwwwwwwwweeeeeeeeeee