Let’s make this easy. If you want to install Renogy solar panels on your van, check out the video right here. But if you need even more help and some extra details, scroll down a bit further for the step-by-step written version. Either way, by the end of it, your solar panels will be installed and you’ll have all the electricity you could need…if you’ve designed the electrical system correctly.

How to Install Renogy Solar Panels – Video Edition

How to Install Renogy Solar Panels – Text Edition

For those of you that need a few more details with your Renogy solar panel install, here’s a 10 Step how-to that will follow along with the video.

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1. Put the solar panels on top of your van where you’d like them to be installed

I had the general idea of where I wanted the solar panels to sit on top of my van, but without dry-fitting them first, I would have overlooked how the mounting holes actually lined up on the contoured roof. It’s also good to see how your flat panels will lay on a curved roof. I ended up needing some additional washers to make a solid mechanical connection with some of the outer mounting holes.

2. Mark the holes for drilling with a dry erase marker

Once you’ve got the solar panels placed where they’re going to live permanently, use a dry erase marker to mark the mounting holes. Make sure you double and triple check everything is where you want it. Once you start drilling holes in your ceiling, there’s no turning back….easily.

3. Hold your breath and start drilling 24 holes into your roof

The Renogy installation manual calls for a 3/8″ well nut (expansion nut) to be used for mounting the panels, which can be purchased directly from the Home Depot. That also means you’ll use a 3/8″ drill bit, but again, YOU’RE DRILLING HOLES IN YOUR ROOF!! Make sure the drill bit really is the right size for the expansion (well) nut. i.e. You didn’t accidentally grab the 1/2″ bit instead of 3/8″.

4. Drill a hole and add a grommet for the extension cables

The standard MC4 cables that come permanently mounted to the panels aren’t long enough to go directly to the charge controller, no matter if you’re hooking them up in series or parallel. Because of this, you also need to purchase MC4 extension cables, and this is how the electricity is going to travel to the controller.

The best, physical way of accomplishing this is drilling another hole or two in the roof for them to pass into the living area or wherever your charge controller is located. The sheet metal of the roof is sharp and jagged after drilling so you’ll also want some rubber grommets to protect the cable. The inside diameter of the grommet should match outside diameter of the extension cables for weather proofing, and the outside diameter of the grommet can be of any size as long as you have a matching drill bit to drill the hole.

Once you’ve got all that figured out, drill the hole, file down any sharp edges, and pop the grommet into place.

5. Layout panels on the ground and verify electrical connections

This probably could and should be done before Step #1, but since I’m following along with the video, it ends up here.

You want to do this to make sure your cables are long enough and can actually make the physical connections once the solar panels are mounted on your van. It also gives you a chance to verify the panels are working by checking the voltage, and that you clearly understand how to connect the panels to each other (series or parallel).

The panels are “12V” so if you have a 12V system, you should connect them in parallel. In parallel, the voltage of the whole system stays the same, but the output current of each panel adds cumulatively. If you have something other than a 12V system, some combination of series and parallel may be necessary to achieve your system’s design rating. Remember,

In parallel connection, the voltage stays the same and the current is additive. In series connection, the voltage is additive and the current stays the same.

Also, I say the panels are “12V” because they will actually produce 20V +/- 2V in direct sunlight with no load. This is no problem for a 12V system because the charge controller is what regulates the voltage and current sent to the battery. But if you have a 24V system or higher, you need to make sure the panels are capable of producing that voltage or connected in some form of series to achieve it.

Lastly, in order to connect your panels in parallel, you’ll need an additional cable assembly to combine all the positive and negative wires.

6. Install the extension cables

The Renogy extension cables come with standard MC4 connectors on one end and rough-cut on the other. Feed the bare, rough-cut end through the grommet from the outside of the van. As soon as you can, grab cables from inside the van and pull them through. You’ll probably have a lot of extra cable you don’t need and pulling is easier than pushing.

Pro tips: Use some lubrication on the cables so they pull easier through the grommet, AND don’t pull too fast or you might pull the grommet all the way through the roof. Then you have to figure out how to get it back in the drilled hole.

In the video, you’ll see that I have two cables going through one hole. That’s because there was already existing holes in the roof from when I bought the van so I didn’t want to drill even more. I got lucky in that they were a standard hole size and big enough to fit a grommet with two cables. To weather-seal the tiny gaps created by two cables in one circular hole, I used moldable putty to fill in the empty space.

7. Weather seal everything

Even though the expansion nuts are rubber and will…expand…I still don’t trust they’re 100% water sealed or that they couldn’t dry out, crack, and/or rot; therefore, allowing water to leak into my ceiling. I reinforced the seal of every expansion nut and the extension cable grommet with waterproof, 100% silicone where the rubber meets the metal. The theory behind silicone, as opposed to adhesive, is that it will expand and contract with the weather and not crack or break, losing the water seal.

8. Connect and mount the panels outside

The silicone should be set well enough in an hour or two in order to mount the panels. First put all the panels on your roof and make the electrical connections with the MC4 connectors. Once you’re happy with the connections and cable routing do one last voltage check inside with the digital voltage meter to make sure everything is truly connected and working properly.

After everything checks out, it’s time to screw down the panels. Make sure every machine screw has a flat washer and a lock washer. These only need to be tight enough to completely flatten the lock washer. No need to crank them down with all your might. If you’re using a cordless drill or impact driver, make sure the torque is set extremely low so you don’t strip anything out or damage something. You can always check by hand if it feels tight enough.

9. Connect the panels to the charge controller and battery

At this point there’s just two connections left:

Solar panels to charge controller and charge controller to battery

Solar Charge Controller to Battery

Per Renogy’s installation manual, we should make sure the solar charger is connected to the battery first. Your system and/or solar charger may be different than mine so I’m going to leave it up to you to do the research and make sure you have everything connected per your manufacturer’s instructions.

The only thing that can be said in all generalities is that the positive output of the charge controller should be connected to the positive input of your battery [system] and the same for the ground/negative/return. The best ground connection is directly to the chassis in the shortest amount of distance if possible. If not, you can run a wire directly from the controller to the battery terminal, which at some point absolutely must be grounded to chassis.

If you have some kind of master switch for the entire house electrical system, make sure that it is also turned ON before connecting the panels.

Solar Panels to Solar Charge Controller

You should have two wires (positive and ground) coming in from your panels with no connectors on the end. As your controller can be different than mine, make sure you use the correct mounting terminal. Here are few common connecting methods that might be on your solar charge controller:

Plug-in type connector – terminate your panel wires with the correct mating connector.

Machine screw connectors – I recommend terminating your panel wires with a spade or ring terminal.

Set-screw – strip some insulation off the end of your panel wires and make sure to tighten it as much as possible.

Once again, in general, the positive output of the panels should be connected to the positive input of the controller. Same for the ground wire. In this case, the ground is NOT tied directly to chassis, but must be connected to the negative input of the controller.

Safety tip: If possible cover the panels with cardboard or some other material to block the sunlight. Once sunlight hits the panels, they begin creating voltage and could cause a voltage spike when connecting to the controller or cause a short circuit if you accidentally touch bare metal with both positive and negative terminals.

10. Drink a beer and be amazed

Congrats! You’re now off the grid! If you’ve done all the calculations correctly leading up to the actual installation of your system, you may no longer need to rely on the alternator or any other charging system.

My 300W panel system is enough to power my refrigerator, charge my electronics, AND charge the batteries at the same time when in direct sunlight.

If you need help designing your system check out my electrical design guide. If you still have questions after that, feel free to give me a call.

And the video once again. Just in case you missed it the first time.

How to Install Renogy Solar Panels Video 1 More Time

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