camper solar

Solar system in the motorhome, installation, assembly, wiring and integration into the electrical system in the motorhome

Here we have an article from one of our customers for you. We asked our customers to write a detailed report about how they installed our solar systems on their caravan.
Our shop customer made the decision to order the 200 watt premium solar system from our shop.
As soon as it arrives, we will tell you about the installation. The delivery of a solar system always depends on the availability at our manufacturer. Our manufacturers naturally deliver to us as quickly as possible, because the solar market is currently extremely booming, delivery delays can sometimes occur. However, this then amounts to a maximum of two weeks, because the solar systems have to be built for us. Of course, we always have various solar systems in our warehouse here in the US, but as it usually is, the customer always wants the product that we don’t have in stock at the moment 😉


In the event of incorrect or incorrect application of our instructions, we are not liable for damage! We no longer consider ourselves as laypersons, but rather as advanced hobbyists who “know they do”, but we are also not trained and trained experts in electricity and solar!
So if you use our instructions for your own installation, please keep in mind that you may run into other problems! You can face hurdles and obstacles and there may be questions that we may not have covered in our report!
So you should ideally see our experience report of installing a solar system in the motorhome as what we wrote it for! As an aid to assess how high the approximate work and material expenditure is and whether you trust yourself to do it yourself based on your knowledge and skills! Your own solar system is a completely different house number than e.g. replace a window seal or install a mini Heki! You need a certain level of advanced knowledge and craftsmanship. If you do not have the confidence to assemble or connect a solar system yourself, please speak to a professional and instruct them to install your new solar system on your mobile home or house.

Of course, you have to know that it is very dangerous to work with electricity. If you have no experience in this area, please always ask a professional first!

So after we have these introductory words briefly … * DINGDONG *, oha! The parcel carrier is here! Well finally! It can go to the installation of a solar system in the camper!

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1.) Delivery, unboxing and preparations for installation
The delivery reaches us in just 4 days. That was quick! The delivery consists of 2 packages. A long one with two combined solar modules and another thick package with all accessories, charge controller, cable, sealant / adhesive, battery clamps, Bluetooth dongle, roof brackets, screws and so on.
Of course, we first unpack everything and check whether everything is really there and no part of the transport has been damaged:

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Now of course we are looking for instructions. We find these after some searching and are a little confused. Because it is a pure text instruction, printed on both sides on two A4 pages. We initially put the stapled papers on one side because we had kept them for general safety instructions such as “Do not work on the ladder without holding on to them” or the like, which, frankly, probably hardly anyone reads anyway.
Instead, on these pages, packed in pretty static sentences, there is actually a description of how the solar system is installed and connected. Without a single picture, without a drawing!
Anyone who has ever built an IKEA wardrobe or bed will surely know the multilingual picture-only instructions from IKEA. With the drawings that everyone understands. If there is a counterpart in the universe, the instructions from the manufacturer would be close … 😉

Addendum: In the wake of our installation report, we contacted the Campers shop again and referred to the unusual operating instructions without any pictograms or drawings. Of course, the written text is enough! But then you should understand what you are doing! Absolute laypersons could possibly have problems with the instructions as they came with our package! Advanced users, on the other hand (which we call ourselves cheeky), definitely get along, even if we have to read several sentences several times! And professionals? They don’t need any instructions anyway … 😉
Campers-Shop gladly accepted our comments and wants to see if they can improve their instructions. That would be something!

One thing is important before you go to the installation. Something that no matter whether IKEA stick figures or text instructions have in common in any case.
The need for the “second man”!
We have already carried out many additions, extensions and conversions to the mobile home or caravan. But installing the solar system with two people was rarely as important as here!

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2. Installation of the solar system in the motorhome (installation of the solar modules on the motorhome roof)
After we have checked that all parts of the package are completely ready, we start the installation. It is important that you catch a day with good weather! Not only should it be dry, but also warm! Reads great, others write, rarely works during the winter break. But we were lucky that at least a few days at a time in the sun it was already around 10.12 ° C. This is important! That at least the sun has been shining on the roof for half a day so that it warms up! Otherwise you have to help with a hair dryer! If it is cold, the sealant / adhesive adheres less well despite preparation and does not distribute itself optimally when the holder is pressed on! Speaking of adhesives / sealants: You should also warm that! PreVent even suggests that the agent should be warmed to 35 ° C before it is processed. The tip is not unjustified.
Incidentally, we are NOT working with Dekalin Dekaseal 8936 for the first time! Because this is ONLY a sealant, small adhesive! Since the roof brackets are only glued and not screwed, the sealant must of course also stick!
For this purpose, the manufacturer includes a tube of Dekasyl MS-5 in the set. Since we trust the products, the manufacturer gets a big plus from us at this point! Could have been any no-name cheap product in a set for a dollar cheaper …
But more on that later, gluing is still a long way off.

By the way, another important note: If possible, plan your work so that you can leave the motorhome in place for a few days after the installation of the solar system! This is important (and, incidentally, can also be found in the enclosed safety instructions for installation), so that the adhesive can spread and harden optimally! Do you drive e.g. with freshly applied and just dried glue, the movement and stiffening while driving can cause small cracks and cracks in the sealant, which can lead to leaks! So if at all possible, you should let the motorhome rest after the work!
Ideally at least 2 to 3 days up to a week before you go on tour with your new solar system for the first time! I know that can be difficult! But there is really no use if the best work is ultimately nullified by a leak.

Before you can start with the installation, of course you have to prepare the motorhome inside. Take a look at where you ideally want to put the cable into the interior of your motorhome through the ceiling.
With his motorhome, Thomas decides for the first cupboard right after the alcove bed on the driver’s side. Some cables are already running there, both at the factory and afterwards. Fixes (already here you need the second man!) The hole approximately on the inside and compares this with the outside on the roof. The site should ideally be easily accessible from both sides after installation. Both from the cable on the roof and later in the interior.

The location of the solar panels on the mobile home roof is the next point!
Thomas, of course, is interested in the best possible light output on the one hand and in a proper alignment on the roof with the shortest possible cable paths on the other. Furthermore, of course, none of the mini Heki roof hatches should be hindered and positioning on the roof rack in the rear area is out of the question, since Thomas occasionally carries sports equipment for water sports. The rear rear area with the roof rack of the motorhome should therefore remain as free as possible!
In addition, for easy access to cleaning, the solar panels on the roof of the mobile home should be aligned as far as possible on the edge and not in the center, so that standing on the ladder is good for spring cleaning.
As far as the desired concert …

In order to find the best possible position for the solar panels on the roof later, we simply use the empty boxes of the solar modules as templates!
This prevents us from having to push the expensive panel back and forth on the roof and scratch the roof or the panel itself.
With the cardboard template you have to take into account that the holders have to be installed later, so you need a little more space! But it is always enough for a first orientation.

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After moving it a bit on the roof, Thomas decides to position it lengthways and once sideways in the direction of travel. We believe that depending on the course of the sun, we can shed a little more sun on one and the other panel during the day than if both are oriented in the same direction. Of course, we cannot prove whether this is true with a formula or even a scientific study. But it sounds logical. 😉

After we have found the right orientation on the roof, the holders must of course also fit! The boxes are used again for this. Now we cut out the outlines of the solar panels exactly from the boxes, so that we can move the cut pieces of cardboard back and forth instead of the panels on the roof! Our choice of position on the roof also seems to work with the brackets, in the front area of ​​the motorhome roof we can attach one panel lengthways and one across the direction of travel. Perfect!
We now mark the position of the holder on the roof with a pencil. So we can remove the holder again and do not have to fear that it will slip accidentally and the panel will surprisingly not fit later.

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By the way, when determining the final position of the solar modules, we took into account another positive feature. Thomas wants to position the roof duct so that it is covered by a solar panel, provided the solar modules offer enough scope.
This variant would be quite attractive and would have two advantages:

– Firstly, the roof duct would be e.g. better protected against rain, sun, wind and weather even by heavy rain thanks to your own panel! Not that this is necessary. Of course, the components are also absolutely usable for direct “outdoor use”. An additional advantage would be that the own solar module even covers and protects the area of ​​the roof opening.

– In addition, it not only looks a bit more discreet on the roof, but also offers a small advantage in terms of cleaning! Cable ducts (or other elements) laid on the roof form corners in and in which dirt collects. If the passage is now ideally directly under the solar panel, this corner of dirt is largely eliminated and the installation of cable ducts can be dispensed with.

As a test, we place a “correct” module in the positioned holder and see if the roof duct cover can disappear under the solar module. And lo and behold: it fits! Very good! So we kill two birds with one stone!
Thomas now only measures once in peace whether the determined distances of the cover on the roof match the determined dimensions in the mobile home in the small closet. So that we don’t have a surprise later…

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Next is the breakthrough through the roof! Although “breakthrough” sounds a bit too brutal. We pierce it. As small as possible and as big as necessary. The “compromise” between possible and necessary is a 10mm drill that Thomas clamps in his small cordless screwdriver. Yes and then? Then even the otherwise experienced hobbyist Thomas costs a bit of effort to drill his own mobile home roof … 😉

By the way, the hole comes out in the desired place in the cupboard. Everything measured correctly! From the inside, the hole could have been a little closer to the side wall, but the compromise to position the roof duct on the roof at the desired location was more important, especially since the cable will later be placed close to the wall in the cabinet with cable holders and so it doesn’t really bother.

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Thomas checks the freshly drilled hole in his camper roof and tests the cable once. It fits perfectly.
The roof opening is then deburred with a file and the aluminum skin is rounded off so that sharp corners and edges do not damage the sheathing and insulation of the cable when it is pushed through later. Then we pull the cable from the inside of the camper through the roof to the outside.
Of course, we make sure that the cable length is long enough to be connected to the solar panels.

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If something could be improved at this point, a kind of “roof opening” would be a good thing. Just like the fireplace of the mobile home heating, only smaller! The cable could then be routed safely through the roof so that it does not rub against the insulation when pulled through. On the other hand, such a roof duct also requires a larger diameter, which requires a larger hole in the roof. Something that doesn’t necessarily have to be if it can be avoided.
We are not worried about the tightness at this point. On the one hand, the roof cover (which is also located under the panel) will be completely sealed, on the other hand, we will add some sealing compound around the hole in the roof around the cable as soon as it is certain that the cable end on the roof is long enough and no longer has to be moved. That will hold!
Nevertheless, we will of course keep an eye on the roof penetration in the near future (as, by the way, basically all critical points such as skylights, chimney passage, etc.!) As part of a regular moisture check in the motorhome.

After the cable has passed through the roof and sealant has dripped into the hole, the cover for the cable duct on the roof continues.

Roof and cable housing must be clean! For this we first remove the coarse dirt from the roof. Normally with a little warm water and a small sponge.
For any stubborn dirt such as grease or resin, the enclosed cleaning kit from DEKA is used. With the enclosed special cleaning cloth and the primer (activator) also included, we wipe the roof thoroughly clean at the planned location. And lo and behold: there is actually still some gray smear in the cloth!
The cover itself is also prepared before gluing. First, it is roughened from below at the later contact point to the roof with the sheet of sandpaper that is also included. Then removed from the dust and also processed with a cleaning cloth and primer. If everything is dry, the next step is to glue.

Of course, you still need a few items that are not available to buy or order in the shop, but we get most of them in our local hardware store.

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Now the sealing silicone is being used for the first time!
Because in the next step we will glue the fully assembled roof duct to the roof!
Thomas, who is extremely experienced in pulling small sealant sausages, also draws his serpentine path artistically and confidently with his solar system. Thomas makes the sausage about as thick as a cable, so the thickness of the solar system cable is a good comparison value!
By the way: The second man pays off not only when aligning the panels, the brackets, when drilling through the roof or just now! One holds the part and angled it optimally, the other pulls the web with the sealant / adhesive. So nothing smears and everything stays where it should stay.

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After the sealant has been applied, we press the roof cover firmly onto the motorhome roof and hold it down for a few seconds. You did it right when some sealant oozed out of the sides. You can remove it later so that it looks nicer and the adhesive does not catch any foreign bodies at this point. We’ll probably leave it that way because it doesn’t overflow. Let’s see.

The next step is to mount the holders for the solar panels on the roof. We do this in the same way as for covering the roof duct. So pre-clean the area on the roof, then treat with a cleaning cloth and primer. The holders are also roughened again with sandpaper at the later contact point, then freed from abrasion and then also treated with a cleaning cloth and primer.
Then there is the skilful application of the adhesive / sealant sausage.

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The adhesive should have a thickness of at least 2, better 3mm on the glued elements (i.e. on the roof duct and all four or 8 holders!) After pressing on and gluing on the roof! Since the plastic elements and the roof of the motorhome are made of different materials, both also have different lengths when temperature changes. This difference in length must be compensated for by the adhesive and therefore it also needs this minimum thickness!
So please do not save with the adhesive / sealant! The content of the tube is enough for all 8 holders of the two modules, the roof opening and of course also for the opening cover over the hole in the roof! You’re not doing yourself a favor if you save on the sealant here!

By the way, for the sake of security, we first just stick the first two on the short side and use the cardboard to check whether the long ends still fit. At this point we could move the holders a little bit despite the glue! But we don’t have to.
We can therefore treat the two brackets at the long end accordingly and glue them to the roof of the motorhome.
Finally, we even put the solar panels in the holders for the first time! This is because the continuous weight of the solar module exerts additional pressure on the holder so that the adhesive can spread better.

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By the way, the boxes will be used for a third time at the latest! Because the solar panels are already producing electricity!
Although the current is currently “evaporating” in the line, since the panels are not connected, we do not have to provoke a short circuit due to carelessness in the subsequent cable work. The cardboard of the cardboard is placed on the solar panels and thus covers them.

Before we finally screw the solar panels into the brackets, the next step is to wire the two connections on the roof!
Again, make sure that the solar modules are really well covered, because as I said, otherwise electricity is already flowing through the line!

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When connecting the solar panels to the adapter, we now notice the missing sketch in the instructions on the butter side for the first time (i.e. negative). Because the two plus lines from both modules have to be connected to a plus line. Likewise the two negative or ground lines. What sounds simple and logical in theory is not that easy in practice!
How do the cables get into the adapter? The indication “+/-” on the Y adapter is not entirely conclusive, even almost contradictory!
Finally, Thomas no longer looks at the symbols attached to the Y-piece, but simply connects the plus from panel 1 and plus from panel 2 in the first switch and connects the single end to the plus cable, which protrudes from the roof edge. Ideal orientation point: the color of the cable! The enclosed cable is provided with red insulation. The same applies to the cables of the modules!
Simply connect all the red cables to one another in a Y adapter and simply connect all the black cables for the minus or ground in the second switch! Then you are not doing anything wrong. Which cable adapter you use and what it says on it doesn’t matter much.

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After Thomas has properly wired the two Y-adapters and is sure that the cable route between the panels on the roof is now sufficient and no longer needs to be corrected, he fixes the cables to the frame of the solar panel using cable ties.
For this purpose, he drills the frame of the solar module at a free location and then leads the corresponding cable tie through the hole. By the way, Thomas uses bright cable ties because they absorb less sunlight and the plasticizers in the plastic do not harden as quickly and the cable tie breaks in the end.

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After the cable from the cross module to the Y adapter has been laid and fixed under the longitudinal module, the final assembly of the solar modules in the holder follows!
To do this, Thomas first drills a small hole through the holder and the frame with a 4mm drill. The hole is as large as the core diameter of the screw, i.e. the thickness of the screw measured on the inside of the thread. Thomas deliberately does this. Although the screw can then be screwed in a little more difficult, it also cuts through plastic and metal and thus holds together optimally later.

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When screwing in the screws, Thomas makes sure that he does not immediately screw both screws onto a holder, but rather turns them “crosswise”. This is so that there is not already a fixed voltage at one point and in the end the pre-drilled holes no longer match the holes in the aluminum frame of the solar module.

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After all screws have been screwed in and we have cleaned the roof a bit and freed it of plastic residues and crumbs, we now have to do the wiring inside and the connection to the electrical system!
Attention! Make sure that the solar modules remain covered in any case! If the wind comes up, you may have to weigh the cardboards down a bit before you are in the vehicle and only too late notices that the cardboards are just flying away! 😉


3.) Connection of the solar system: Integration into the vehicle electrical system / electricity network of the motorhome
After we have finished the work on the roof, we continue inside the motorhome. Before Thomas connects the solar system to the vehicle electrical system, the supply cable is laid properly. To do this, he saws out the shelf of the cabinet a little in a corner and first runs the cable through there without fastening. In the lower half of the cabinet, the base plate is not completely continuous, here Thomas can simply push the cable through and comes out below the cabinet.

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In the direction of the floor, Thomas now routes the cable along the fender (the transition from the cab to the living area) and leads the cable into the chest right behind the driver’s seat. A part of the fresh water tank is located here and there would also be space for the second body battery. In the further course of the installation, Thomas decided to first remove this battery and have a look whether the first battery (due to the design is already under the driver’s seat of the motorhome from the factory) can be used for the newly available solar power the power requirement is always covered so that Thomas can permanently do without this second battery.
If this works, you might have to consider whether the body battery will move to this location! This is because the temperature control of the charge controller only works efficiently if it is installed directly next to the battery. For the first year, however, Thomas first tried the installation variant in the seat chest and left the battery even under the driver’s seat, where it is installed as standard.
After the cable has been laid through the individual bushings, the charge controller is connected immediately.

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Installation and connection of the charge controller for the solar modules
Before you integrate the charge controller into the on-board system, please observe these important basic rules:

1. Disconnect the battery (s) from the vehicle electrical system at the latest now!
2. Make sure once again that the solar modules on the roof are really covered and don’t supply any electricity!
3. FIRST connect the battery to the charge controller! Only then are the solar modules connected to the charge controller! (we’ll explain why this order is important)

Thomas has positioned the charge controller in the dinette’s seat box behind the driver’s seat. He cuts off the cable that comes from the roof and can easily lay the cable from the solar charge controller to the body battery under the driver’s seat along with the remaining piece of cable. Here, too, the cable ends of all 4 cables (2x from the roof with plus and minus and 2x from or to the battery with plus and minus!) Must of course be equipped with ferrules! This is also because the wires of the cable itself are a little too thick to be connected directly to the solar charge controller.

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After the power is supplied from the charge controller to the battery, Thomas connects the cables from the roof to the charge controller. Of course, the solar modules are still covered now!
The order is important! If you would first connect the solar modules and they immediately supply plenty of electricity when the sun is shining, the charge controller would erroneously interpret another electrical system and e.g. switch to 24V mode! Because the charge controller is first connected to the battery, the charge controller automatically adjusts itself to the 12V electrical system!

If the cables of the roof and the battery are connected to the charge controller, the charge controller is mounted on the seat box. It is simply screwed to the wood of the seat box in Thomas’ motorhome with 4 screws. At a later date, the body battery (currently still under the seat) will be moved to the same place in the seat chest (the second body battery that Thomas threw out as part of the installation of the solar system is now clearing the space), so that Temperature control of the charge controller next to the battery can work successfully.

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Finally, the plug of the Bluetooth dongle is now connected to the charge controller. By the way: A dummy is on the plug connector for the Bluetooth dongle to protect the plug! You have to remove it before you can connect the Bluetooth dongle.

Once you have connected the Bluetooth dongle, connected the battery to the charge controller and also connected the solar modules, the decisive moment comes. The solar modules are revealed!

The great anticipation of almost unlimited electricity thanks to the sun is replaced by an incredulous surprise! After the app is finally ready to start, the app shows no current flow. Did we do something wrong? No. The solution is simple. We have been tinkering with the camper for so long that it has become pitch black outside! In any case, electricity no longer arrives in the motorhome today.
As a precaution, we cover the solar modules on the roof again for the night. The premiere has to be postponed until tomorrow … 😉

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4.) Let there be light, * uh * electricity! The solar system in the first function test
The next day, the time has come! After Thomas removed the cover of the solar modules the next day, electricity flows immediately!
It is particularly nice to look up in the app, but the charging current is also immediately displayed on the on-board control panel. The fact that the pointer deflects very weakly towards “charging” is not a fault in the system, but due to the fact that the battery is still almost to the brim and the charger therefore only provides a trickle charge. But Thomas will put the system through its paces in the next few days and weeks and will certainly bring us more pictures with more impressive numbers.
We will report on this in Chapter 3 “Long-term experience” at the end of the year at the latest and then again and again in the further course.

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A few words about the Victron app, which is used to read and control the solar system:
The free app is quite normal via the app store e.g. available for Android phones!
Thomas had no problems installing the app on his S3 Neo cell phone. The connection also worked immediately and without any problems. That surprised us a little bit positively!
The advantage of the app and especially the wireless connection is of course obvious! Due to the position of the charge controller in the storage box, an additional control panel of the solar system would also have to be attached to the panel board of the motorhome. This is in Thomas motorhome (Dethleffs A 5880 HG) above the main door! So a cable should have been laid from the storage compartment of the seating group to the body door. An unnecessary effort!
Especially if you can do without the extended options of a separate control panel, as in Thomas Fall. The serial wiring in his motorhome is already so well designed that the charging of the battery and the voltage status are also shown on the standard panel. So also that the solar system charges the battery! We have not laid any additional cables for this, this is already ensured by our own on-board system.
The app is also intended for programming the solar controller. Thomas switches e.g. the system immediately into 12V mode so that it e.g. when removing the battery, not even accidentally feeds too much voltage into the battery.

We’re done with it for now! Even in adverse weather conditions, the solar system runs and supplies enough electricity to always supply the body battery with electricity when the camper is parked.
A first endurance test under real conditions will show whether it is also enough if the solar system should not only provide electricity to maintain the battery’s state of charge, but can also compensate for correct daily consumption by feeding in electricity! Only then will it be proven whether the system is really not only sufficient, but also really spacious. We are really very satisfied with the quality we received from and would like to thank you again!


Finally, important and worth reading about these installation instructions:
At the end of this installation report of our solar system in the mobile home, we have a few key points for you:

Assembly time:
We built around 3-4 hours in the afternoon on 2 days each. So we had a total effort of about 8 hours for the complete system with installation and electrical connection of the solar system to the vehicle electrical system in the camper.

Tools required:
Use scissors or a sharp knife / carpet knife to cut the outlines of the panels from the box. Then a good cordless screwdriver with drilling function and two drill bits. One 10mm for the roof opening and one 4mm for the holder and frame of the solar panels.
For the electrical system, we needed stripping pliers for the cabling, as well as crimping pliers for the cable lugs or ferrules. The wire end sleeves are ideally soldered with a small soldering device.
A thin round file was used on the roof to file the hole. Here and there a screwdriver or a chuck insert “cross” for mounting the solar panels in the holder. You should also think of an open-ended or ring spanner for installing / removing the connections to the battery.

Required consumables that we had to buy outside the set at the local hardware store:
In the set everything was included! Not only the charge controller, the panels, the Bluetooth dongle and the sufficiently long cable, but really every wire end sleeve, every screw, the battery contacts, the cleaning agent, primer, and even the sanding paper were included in the package! This is rarely as good as it is! We only provided some cleaning supplies and a sponge for the rough pre-cleaning on the camper roof, so nothing that would not be available in the household anyway.

The solar system installed here:
We have already linked the system one or two times in the article. For the sake of completeness, we list them again here. The solar system installed by Thomas is the 200 watt premium solar system with charge controller in the complete set from Here is the system: 200 watt premium solar system. Of course, you can also install other solar systems, with higher or less power. You can of course also install more solar panels on your roof.

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