Connecting External Solar Panel Array

[rvsprinterguy]

Hi Everybody,

I just purchased two 100-watt solar panels and a charge controller. I don't want to mount the panels on the roof because I'd rather be able to park in the shade when possible.

My idea is to arrange them some reasonable distance from the van using whatever gauge of cable is necessary to minimize loss.

My question is, how to best connect the cable between the controller and my onboard battery? I'm thinking Anderson Powerpole connectors using a weatherproof panel mount housing such as the one sold by Powerworx.

Has anyone done something like this?

[GallenH]

Well about a year ago I bought a Renogy 100w suitcase package that came with a controller and an "extension" cable that terminated in battery clamps.
The extension and the cabling from the controller was only 14g. I upped it
to 12ga. You're looking at 200w, however, and I would defer on what this means gauge-wise to someone with more electrical knowledge.

I can tell you that I took the cable from the battery to the trailer hitch area so
that I could do a "plug-and-go" when connecting things up at the campsite; much like you're talking about. I went with MC4 style connectors since they originally came with the suitcase. Those were extremely hard to disconnect without some pulling even using their special tool. Bad choice; maybe they're ok for more permanent installations. The connectors that you're looking at appear to be a better choice. Not sure how you intend to mount the port on your RV. I was able to put an outdoor box on part of the frame and didn't go through the body of the RV.

[rvsprinterguy]

Thanks for your reply.

I was thinking along the lines of drilling a new 1-1/8" hole in the van body. I'd prefer to minimize the length of the cable run inside, so I was leaning toward trying to mount the Powerwerx panel somewhere on the passenger side.

Instead, I think I'm going to mount the panel inside the utility box, where the AC power cable and the water connections are. So, no new hole in the body with its potential rust issues.

How have you liked the Renogy kit?

[GallenH]

What I actually did was to convert my connectors to standard 120v plugs. My unit is older than yours; a 1997 PW. There was a structural plate coming down in the rear by the trailer hitch that I drilled holes through and mounted a standard outdoor box. I bought a special receptacle with a rubber cover meant for RVs, but realized afterwards that I could have just used a standard outlet and a weatherproof outlet cover. I had to change the plug on the Renogy controller outlet from the MC4s to a standard plug. My first test was with a standard 12g outdoor extension cord. Seems to work fine.

Caveat: many extension cords are not solid copper. Choosing a cheap one means the 12g is functioning more like a 14g. I think. From what I've read.

I like the Renogy. I have relatives that work the Cibola wildlife refugee in the winter months. That's in AZ but right on the Colorado river. They stay in their A and tow a Jeep. So when we're there, we're just boondocking on BLM land and don't drive at all. No generator. The Renogy charges my single 100AH to 100% in a half day. I think the ability to have it at an angle pointing directly at the sun is a plus even if you find that when the shade shifts in the campground you have to reposition the panel.

But, I find that when we're on the move, the alternator has it up there quite quickly. When we went to Glacier for 2 weeks last year, I took it but really didn't need it that much unless we were static for a few days.

[SteveJ]

I'm using this style of connector:

https://m.media-amazon.com/images/I/...RCH212385_.jpg

I'm using 12 ga cord for 150 watts of panel. Max output is about 8.5 amps. !0 ga would likely be better for 200 watts but 12 ga would work with a small voltage drop on a long wire run at full output. More importantly, use 10 ga from the controller to the battery. I also have the Renogy panel and the older Adventurer 30 amp controller with temperature compensation. I relocated the controller to the interior of my Roadtrek, near the battery.

For a cord I have 25' attached to the panel, a short one to jumper the other panel, and a 25' extension cord, all with the above connectors. I have basement storage in the 200V so that's where I have a lead to the controller from the panels.

This system has worked fine for me. I do make it a point to keep all connections high and dry to avoid any shorting issues.

The connectors have been reliable and are quite easy to use.

All electrical connections were soldered, shrink wrapped and taped with a copious amount of 3m electrical tape.

[GallenH]

Speaking of high and dry. I was experiencing some corrosion with my Renogy ring connectors to the battery. Got so extreme that it made for failed connection. Recently tried this:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

It's what marine guys swear by. And they are the kings of corrosion. We'll see in a few months what the ring connectors look like.

[cullenskink]

I use the anderson power poles on pretty much everything 12V. They work really well, can be con be configured into more complex blocks than just +ve and -ve etc. The housings have a number of options for protection from the elements. (don't be random on what side you put the wires, I use the SAR's standard which is also common in the Ham radio community)

The standard 30amp housings, can take inner connectors for 15,30 and 45 amp capable connectors. given that you are connecting 200w, amperage will be 16 amps or less. For this you can get by with 14 gauge wire. However it would be little more expense to use 12 gauge and you would have capacity to add more panels.

Ampacity table
Wire Chart

[bl_smith25]

The charge controller should be mounted inside near where the batteries are located, but not exposed to any offgassing or weather. Run good size short wires from the controller to the batteries. No longer than 1-2 feet to reduce voltage drop. Tenths of a volt count!
Then you can put your panels anywhere and run whatever length of cable you need to get to the controller. The solar panels put out 19V or thereabouts. Well above what you need for the battery so voltage drop isn’t as much of a concern over a long distance because by the time it gets to the controller, you’ll still have good voltage.
The job of a good controller is if you’ve selected your controller properly for the type of batteries that you have, it’s job is to output what the battery needs to charge at the various stages it provides, hopefully bulk, absorption and float at a minimum. The battery needs to see the proper voltage for the correct duration to charge properly. So the wire runs from the controller to the battery are the critical item here since the controller will take whatever it’s given by the solar panels and output what’s needed for the batteries. Too long a run and the battery will see too much voltage drop to get what it needs and will starve - basically suffer from chronic undercharge leading to a shorter life and early replacement.
I hope this makes sense.

[NFRicaS]

Originally Posted by rvsprinterguy

Thanks for your reply.

I was thinking along the lines of drilling a new 1-1/8" hole in the van body. I'd prefer to minimize the length of the cable run inside, so I was leaning toward trying to mount the Powerwerx panel somewhere on the passenger side.

Instead, I think I'm going to mount the panel inside the utility box, where the AC power cable and the water connections are. So, no new hole in the body with its potential rust issues.

How have you liked the Renogy kit?

I had my local RV place connect a wire from battery out to a plug that my solar battery panel plugs in to...has a pretty long wire, too, so the panel can be moved away from RV. Inside wiring only about 8 inches long..