My thought is to have a short (less than 2ft) wire coming from the controller on the panels as well as coming off the 12V male plug that connects to the trailer. If you connect two of them in parallel, your total amps would be 16 amps Imp and the voltage would remain at 18 volts Vmp.

But I think for the amount of time I would be charging on the road, getting something over 13 volts to the battery in the field will be adequate. This solar connector is used to connect the mc4 plugs of all our solar panels to a compatible SAE camper van connection. Note: Never connect or disconnect solar connectors whilst they are under electrical load as this can cause arcing which can damage the contacts.To travel the 20-foot distance to your equipment, you will need a 20-foot wire with a male connector and a 20-foot wire with a female connector. Unfortunately I don't think there is ever a perfect answer since it's impossible to know the exact future conditions you will find yourself in. That way you can use less expensive wiring (such as THHN rated insulation) inside the electrical conduit to cover greater distances at substantially less cost than the MC4 cables. And even with fridge, radio, plotters, autopilot and occasional radar it seems that these panels are keeping up with my usage. If you're only using two modules, or two strings of modules, the easiest method is to use MC4 multibranch connectors.

I can confidently say the installed systems are up to the task and I can now cruise in comfort eight months of the year. Tip; separate type connectors but useful related to how not to get gunked up electrical connections pro-tip; (thank you Craig and Cary for diagnosis, finding this issue while refusing to let me leave on a late hectic Friday after factory owner tour. Wiring MC4 Equipped Modules in Parallel: Parallel wiring requires the positive leads to be connected together and the negative leads to be connected together.In this case, you will want to cut the extender cable at a spot that allows both cut ends to reach the combiner box with a little slack to work with.

Comes with reverse polarity adaptor - please ensure that the positive and negative from the panel match with the connectors as often the MC4 connectors in particular will be reversed. This may not always be the case, so it's always a good idea to look at the markings on the junction box or test the polarity with a digital voltmeter. Since I can easily swap the polarity when installing this is not a big issue but I will have to remember the connector/polarity of the cables will be reversed. Once the housing is placed on the contact it is difficult to remove so make sure you have the lock ring on the wire first. SAE connectors can get snug to seat fully, which is a good thing as opposed to being sloppy and sliding in easily.You no longer need the multibranch connectors because the combiner box will be performing the same function.

Lyall provided great advice and the systems included cabling, connectors, controllers, and circuit breakers plus guidance for the DIY installer.com/p/Renogy-Male-and-Female-Connector-to-SAE-Adapter-13-AWG-Cable-CNCT-MC4-SAE/301811354" on this server. Even though MC4 connectors appear to shield the actual electrical contacts when connected, when disconnected, those contacts are just as susceptible as SAE connectors to salt air, etc. The other consideration is the gradual loosening up of the pinch action as they are connected and disconnected repeatedly. Over the course of a year, it will get charged much more at home where I can always get max charging. I'm sure people will have a fit when I say how I solved my wire problem between the panel and the camper.