The solar panels
Solar panels have different parameters that you should know to make a decision:
First, there is the maximum power Pmax in watts. You can find this number on every solar panel. I bought 100-watt panels.
Next, the voltage in volts. That's 18 volts on my panels.
In addition, the maximum current in amperes, for me 5.9.
You need these three key figures for the purchase and the comparison.
The panels should provide enough power in one day to fully recharge your batteries. I need about 55 Ah a day and would like to get by for 3 days. So my system has to deliver 165 Ah per day. Less is also enough, as some energy is always coming from the roof, even when it is cloudy.
So I bought 2 100W monocrystalline solar panels to start with and can build a third one on the roof if necessary. If you don't have that much space, buy one or two with more power. Below I recommend various modules.
The charge controller
The charge controller is the third part of a solar system in the mobile home, also called a stand-alone system. This takes the current from the solar modules and directs it to the battery similarly. So it is there to charge your batteries properly. So you must ensure that your charge controller fits the battery or offers a charging mode. Most current controllers can handle wet, GEL, and AGM RV battery.
The maximum power and, above all, the maximum current are important for the controller. I wrote above that my panels deliver 5.9A maximum. Since I have two pieces and would like to reserve a third, I need a controller that can handle at least 18 A and 300 Pmax.
Purchase recommendation solar system mobile home
I'll explain to you why I chose exactly these components:
For the solar modules, I chose a supplier with a good Amazon rating.
- I bought 100 watts because I calculated it.
- For the charge controller, I decided on a branded product against an inexpensive product from eBay. On the one hand, I wanted to have a guarantee and, on the other hand, a display to see how much electricity I was producing and also to have a reserve for connecting another solar panel.
- I bought the two spoiler sets because simple aluminum brackets were too unsafe. I don't want the panels swept off my roof at 100 km/h and subsequent drivers injured.
- I deliberately bought the connection cable with a diameter of 6mm. If the cables are too thin, then there is more power loss in the form of heat. On the one hand, I want to avoid losses and, on the other hand, a potential cable fire.
Installation of the solar system on the mobile home
You should set aside a weekend for assembly. It took me two days to do this. I worked from noon to around 7 p.m. First, I built the spoilers on the panels, mounted the solar panels on the roof, and connected everything. I explain it in Detail here:
Pre-clean the roof
First, I carried a solar panel and two spoilers onto the roof and tried to find the best position. No shadow must fall on it from the roof structure. I then drew the outlines with a pen. So I know where to clean and sand where.
The first cleaning I did was with soapy water and a sponge. Then wipe dry with a cloth. This step is simply about removing the coarse dirt.
Prepare solar spoiler
In the next step, I prepared the spoilers. These are already pre-drilled on one side. First, I had to drill the holes. I used a 3.5mm drill for this.
Then I put the first spoiler on a shelf and inserted the solar module. Because next, I had to drill holes in the module's frame. Pre-drilling is important so that the screws go in well. I used the same drill bit to drill through the spoiler into the frame to get a mark. Then removed, the spoiler was drilled through the frame.
Then I screwed the spoilers to the solar modules with the supplied screws. The spacers must go into the spoiler.
Next up was the roof. In the area marked for the spoiler, I roughened the area with the abrasive fleece provided. The aim is not to completely remove the paint but to make the surface rough. Quite nice work at 30 degrees and sunshine on the roof.
After roughening, I taped the edges flush with masking tape. This makes it easier to remove the excess glue after gluing.
Gluing the solar modules onto the mobile home roof
Next, I pre-cleaned the adhesive surfaces with spirit. First, clean with the supplied activator/cleaner. I used a soft, lint-free cloth to do this. Then the whole thing has to flash off for at least 10 minutes. Next, I applied the primer with a soft, lint-free cloth. Apply thinly to the splice. At the same time, I also applied the activator and the primer to the solar spoiler. The primer must flash off for at least 30 minutes.
After the waiting time, I glued the first module. I turned it over on the roof and applied the adhesive, Sikaflex 252, in beads to do this.
Then turn the module over and stick it carefully and precisely to the area marked with masking tape.
After gluing, you have to press the solar module lightly. The glue should be 2 and 3 mm thick between the roof and the spoiler. Then I glued the second module.
Gluing on a cable duct
Both modules are connected in parallel with me. This adds up the current, and the voltage remains at 12 V. In the basement, I still had a little cable duct that was 5 cm wide. I mounted the C4 Y-adapter in these and connected both modules in it.
Mount the roof duct on the mobile home
Next, I mounted the roof duct on the roof. I chose the spot near the modules and the former satellite antenna. As a result, the cables come out in the large closet, and I can do great wiring. Then marked and roughened. Next, I drilled a hole in the roof with a 23mm hole drill.
Then I glued a small gauge pipe into the hole with Detail. The pipe protrudes a little at the top. If a little water somehow gets into the roof duct, it doesn't run directly inwards.
Then I masked the edge with masking tape and cleaned and primed the surface and the roof duct (as already described for the solar module).
Next, I pulled the cables through and pushed them to the right length. After waiting, I applied the Sikaflex and glued the bushing on.
Then I sealed the two passages from the outside with Dekasil sealant. Since the two cables were thinner than the rubber seals. I didn't use Sikaflex glue because I might have to get to the cable again.
Installation and connection of all components of the solar system
Before I wired everything in the next step, I covered the solar panels with cardboard. As soon as light falls on them, they produce electricity. Since I didn't get wiped and didn't want to sizzle, covering it up makes a lot of sense!
Next, I looked for a place for the solar controller. I bought one with a display so I could always see how much electricity we were producing. Gimmick, but nice and a bit important for us. So it had to be fixed outside the cabinet and as close as possible to the RV battery. I found a place near the bench. Then attach the controller with four screws.
Next, I connected the regulator to the battery. First, I connected both cables to the controller. Next, the red to the battery's positive pole and then the black to the negative pole. This order is important. Since minus in cars and mobile homes is usually also attached to the frame. This way, you avoid short circuits when connecting.
Next, I connected the positive lead of the solar panels to the controller and the negative lead. To make it look nicer, I put the cables in cable ducts that I had there.
Then I removed the cardboard, and we produced electricity and charged the 12v lithium ion battery for the RV. A great feeling.
I needed about 14 hours for the complete assembly. With this article, you can do it yourself too.