IAMICHABOD:
Do you also have a Renogy portable suitcase? My cable is about 10' long and has MC4 connectors about 2' from the pigtail that's connects to the controller. The other end has alligator clamps. Since my batteries are covered and vented in the front compartment of my 5th wheel, it's inconvenient to connect the alligator clamps directly to the battery. I would like to build a new 20' cable that will plug into the existing MC4 connectors and then connect the other end into the receptacle on my trailer. I have a photo of my connector but can't seem to upload it to the post. The connector is a 2-pole receptacle that would take something like this:
https://www.amazon.com/Standard-Motor-Products-POLE-CONNECTOR/dp/B002OPHRXW/ref=sr_1_4?s=lawn-garden&ie=UTF8&qid=1467816103&sr=1-4&keywords=2-pole+flat+trailer+connector
Are the cables you reference very flexible? The connector on my camper doesn't seem very stout. I wonder if I should have a smaller gauge transition to the 2-pole connector so I'm not applying any torque or force on the connector with the weight and stiffness of the cable pulling down on the connector.
It sounds like I can buy the MC4 connector tool and install MC4 connectors on one end to mate with my existing cable and then install a 2-pole connector on the other end to mate with my camper, or buy the cable you referenced and attach the 2-pole connector on the pigtail end.
Thanks for the link to the MC4 cables and assembly tool!