How to Install RV Solar Panels
This is what I'll be installing the solar system on. It's a 2005 Custom GMC Super C.
These are the panels. They are 175 watts each. I'm installing 4 for 700 watts.
I'll be attaching them directly to the roof.
I need 700 watts because I'm running an electric fridge, a swamp cooler, lap top and lights.
I will use 4-6 volt batteries, a 2000 watt inverter and a 40 amp charge controller. More about this later.
You can build a rack for your panels like I did on this Penske conversion.
This allows you to put the scews on the side.
I'm using this extruded aluminum angle to attach them to the roof.
You can buy this at the hardware store and you can cut it with tin snips.
You'll see that I have a 1x2 as a spacer which will raise the panel off the roof to keep
it from resting on the roof.
First I attach 1 side of the angle using "tech tip" zinc plated #10 sheet metal screws.
I will wait until I get the panel on the roof to attach the other end of the angle. This is because there
is a "arch" to the roof. It's very important that the angle "Lay" flat on the roof so there are no sharp edges "digging" in to
the rubber roof creating a whole and a leak.
Next I drill the holes to attach the RV solar panel to the roof. I'm using 1/4" zinc plated lag bolts. I'm
only using 1 mounting bolt on each angle piece. Remember, you are drilling holes in the roof of your nice RV.
Any hole becomes a possible source for a leak. The less holes the better. Just a side note: I'm
writting this 2 years and 5000 miles after the install and 1 bolt each worked great.
After I get the panels on the roof, I then let the angle "settle" on the arch of the roof so it lays flat against the rubber.
Then I can attach the other end of the angle.
I'm using 1 piece of high quality putty tape under the angle to help seal it.
You'll be tempted to use more putty tape but it's more important to get a nice, tight, snug fit when
I put the lag bolt in.
After I place the putty tape in between the roof and the angle, I screw it down.
Being very carefull not to stirp it by getting it too tight.
You can see when it's tight, the putty tape will ooze out.
Then I seal the whole thing with Dicor Self-leveling sealant.
This is the only thing that will stick to a rubber roof.
You want to cover the bolts and the edges of the angle.
Next, I'm running the wires down the fridge vent shaft. There are 4 screws that hold the vent cover on.
Next, I cut a hole in the screen to feed the wire through.
And I just feed the wire down to the fridge.
I seal the hole with putty tape.
The wire I like to use is "Outdoor lighting wire". It's made to be outdoors and
made to withstand the elements. I use wire nuts for connections because I like them
better than the fancy connectors they make. There's really no other way than to just let the wires
just rest on the roof. Just make sure all your positive and negative wires are connected together in parallel.
Do not daisy chain the. This is called
series and the the output voltage will be too high as it doubles with each panel.
And out the wire comes from the back of the fridge.
Then, it's just a matter of drilling holes and feeding the wire up to where you want your charge controller.
I finally had it come out on this cabinet. It's close to the converter and it's where
I can check my battery voltage easily.
Ok, the output of my fpanels comes straight into the charger. The output of the charger connects to the batteries.
The best way to do this is just connect these outputs to the connections in your converter where the batteries
come into it. I'm using this 40 amp MPPT because the output amperage of each panel is 9 amps. I should have a total of 36 amps. However,
I have never seen more than 9 amps come out of the entire panel array. This is a great charger because you can set the charge voltage where
you want. I set mine at 14.3 volts. Most inverters will shut off at 11 volts. This gives my 5.3 volts to use before shut down. I've never
gone below 12.3 volts.
I'm not going to give you a lot of calculations and specs here.
I've arrived at this set up from trial and error which is really a lot better.
I'm have a 2000 watt inverter. I sometimes use a lot of power. The electric fridge stops and starts all day.
When it starts up there is a spike that can be 1000 watts or more for a 100 watt fridge. So, if I'm using a lot of
power these spikes can cause the inverter to overload and shut down. Which means my 2000 watt inverter with 4000 watt peaks
might not be what is advertised. But, it works pretty good for what I have and for the price. If you don't need that much
power, you want to go with a smaller inverter as it WILL use power just when it's idling.
You'll see that I have the inverter mounted very close to the batteries. This is very important.
Long cable runs will use a lot of power. All your cables for batteries and connection to the inverter should be
at least 4.0 gauge.
The output of the inverter can be 12 gauge romex.
This is my remote for the inverter. Works great and it has a simple voltage meter on it.
You'll also see my generator remote, my Input Power Switch and a switch to turn the converters charger on or off.
The Input Power Switch allows you to choose between: Shore, Generator or Inverter power. You need a switch like this so if for instance
you're connected to shore power, you aren't feeding power to the outputs of the generator and the inverter.
This will burn them out. The Input Power Switch isolates each source. Many factory RV's will have electronic switching
which I gues you could get but I perfer 'simple'. The switch has 3 inputs and 1 output. You'll connect Gen, Inverter and Shore to the inputs
then connect the output to the 12 volt input on yourconverter.
The charger switch is required when you connect the inverter output to to converter. When your running off
batteries and you try to also charge the batteries you create an internal loop that will shut the inverter down.
So you need to have a switch that turns the charger off. In your converter you'll find one wire that powers
the charger. Put the switch on this wire.
Buy these solar panels Here
Buy the Edecoa Inverter Here
Buy the Solar Charger Here
Buy the Input Power Switch Here