I use a 100w Renogy suitcase set-up. I needed an extension cord, since here in the northeast we deal with a LOT of shade. It was recommended to me to use low-voltage outdoor lighting wire. I bought a 100' roll from Home Depot, with the thought of cutting off what I needed. I used 50a powerpoles on the ends - figured I'd try the entire 100' length for openers. Since I usually only output around 3a to the batteries from the charge controller, I wasn't too worried. I was unable to see any loss by using the entire 100' roll of cable - so that's what I still have! Meets my needs just fine. I am sure someone much better versed can find fault in my system, but since it works, measured by the ability to keep my 2 12v deep cycles full, I'm happy, and can move the panels as needed over the course of a day to catch plenty of photons! ST