Originally Posted by 44'cruisingcat
You could install either an Outback flexmax or Xantrex XW charge controller, and wire the panels
in series. Then a smaller wire size would be fine.
Not sure what you gain here other than saving the cost of using larger wire at the expense of considerable loss of output when your series-wired panels
are shaded by your mast
pole, clouds, or what ever. Go parallel with #6 wire and call it a day. I have 500 watts of solar
panels wired up this way into an Outback Flexmax controller, and it kicked out 199 amp hours a few days ago. I went six days without running my engine
to top up the batteries.