Categories: RV Solar

Ultimate Off-Grid RV Solar Power System Build

More direct solar energy falls on the Earth in one hour than the entire human race consumes in a year. Here’s how we’re using RV solar panels to capture this unlimited power source to energize our travels.

Using Solar Power on RVs

Many homeowners and RVers like us have been using solar power for years. Solar photovoltaic arrays allow you to take all that free energy that falls on your roof every day and turn it into usable electricity and we have been primarily living off this free energy for over two years.  

We dove into RV solar energy with a cost effective power system to see how we liked it, and we have fallen in love with its silent generation that enables us to easily live wherever we want as we are the power plant. ​

This was at the start of building the first system with 1100 Watts of residential 72 cell glass solar panels.

Check out our previous solar power system! 

PART 1: Installing RV Solar Panels

PART 2: Installing a Tesla Battery Module

PART 3: Installing the Inverter 

We decided to take our solar electric to the next level.

We’re going to be squeezing out as much power as we can get off this 33 foot RV with the latest technology and try some things with an off-grid system we never thought possible.  Join us as we build our Ultimate Off-Grid RV Solar System!

WATCH THE VIDEO:

RV Electrical System Upgrade

With Tom being an electrical engineer and a do-it-yourselfer, he designed and built the whole system himself – so we had no labor costs for both system installs.

For this build we are completely replacing the whole previous system with upgraded technology.

​RV solar systems may seem complex, but if you break it down off-grid solar systems consist only of a few major components. In this article, we will be covering an overview of the components, and you can check out the full schematic below and join our newsletter to get notified about future posts about the new system.

This is the full schematic of our build.

If the schematic seems complicated, don’t worry. We are going to break things down to their basic components.

The Batteries

At the heart of every solar system is the battery which stores the energy for nighttime and cloudy day use. (Every RV solar system is essentially an RV solar battery charger.) We installed a much larger battery bank, 8 Battle Born 12V 100Ah GC2 Lithium-ion batteries. ​​

Our first RV solar system was built with a Tesla Model S car battery at its heart.   This worked very well but was a complex build as Tom had to design the whole battery management system himself to make sure the battery was safe. 

Tesla modules are a lithium NCA chemistry and pack a lot of energy into very little weight, but have the drawback that if anything gets out of spec with the battery they are prone to  catch fire.

While we had built a safe system and never had problems, it was much easier to install Battle Born Batteries for the upgrade.  These batteries have all the protections built in so they can be hooked up like normal batteries.  We also already had 5 batteries from our previous project, the Go North Expedition and this was a perfect opportunity to use them.


The Tesla module is on the right and Battle Born on the left, a few cells of what are in the Battle Born battery sit in front of it.

One of the biggest benefits of lithium batteries is that they can be installed anywhere in any direction. For this build we decided to install them upside down.  Years ago we had removed the black tank from our RV  and installed a composting toilet.  When we did that we were thinking that we might use the space where the black tank was for batteries in the future, so that’s exactly what we decided to do. 

The Battle Born Batteries all hung upside down on where the black tank used to be.

We built custom brackets to hang the batteries upside down where the black tank used to be and wired them all up with the terminals facing down. 

Closeup of how the batteries were installed
The space we had to install other equipment underneath the batteries
Custom mounting brackets notched out for the battery terminals

We wired them in a 24-Volt configuration because with the amount of solar we would be installing we needed a higher voltage system to handle the current.  With larger systems we always recommend building at least a 24-volt setup and possibly even 48-volt. ​
Batteries all wired up upside down and ready to be connected to equipment

The RV Solar Panels

The solar panels generate the power from the sunlight that is used to charge the batteries. In this build we are going to use the latest tech mobile application solar panels to more than double our power production from our first build.

  ​When we were starting to think about a solar upgrade we found out about Battle Born Batteries latest solar product offerings and were happy to hop on board to try them out. 

*Battle Born Solar Panels are currently only available through their Bundle Packages.

We decided to install their 230 watt panels that come in two shapes and sizes, the BBS230A and BBS230B panels.   

Tom holding one of the BBS230B panels prior to installation

We installed 10 panels on the roof of the RV, and because of the cool peel-and-stick design, we also decided to install 2 more panels on the front cap of the RV! 

The panels on the front cap won’t perform as well as the roof solar most of the year, but come wintertime is where they really start pulling their weight. As a full-time RVer, we use our RV year round and solar always struggles in the low sun angles and short days of winter. Continue reading to find out how they have performed!


All 10 Panels on the rooftop, the 4 BBS230A are on the left and the 6 BBS230B are on the right.

Two additional BBS230A panels installed on the front cap of the fifth wheel.

What makes these RV Solar Panels special?

This is a rendering of the structure of these cells. The grid has a wave like design both on the cell and on the connections to other cells that allows for flexibility. It also achieves very high contact and minimizes series voltage drop.

These panels  are unique because they are high-efficiency mono-crystalline cells in a flexible stick down package. 

Let’s break this down:

HIGH-EFFICIENCY. These panels are 19% efficient vs. our previous panels’ 14% efficiency, meaning we get more power out of the same space! This is especially great when you’re working with limited space – like an rv roof.

FLEXIBLE PANELS. In the past we have been leary of flexible panels because they tend to have short lives due to thermochemical stresses internal to the panels, but these panels  have solved that. 

The Battle Born Solar Panels utilize a special grid structure instead of bus bars that allows for considerable movement without breaking.  This structure also puts so many points of contact on the solar cell that if it cracks there is minimal power loss.    

electing RV solar panels can be tricky depending on your needs, but we found that these panels checked a lot of boxes for our RV solar system. 

First, these are very lightweight RV solar panels.  This is huge because weight is such a limiting factor in many RV solar builds.

Second, the ease of installation and no holes to be drilled in the RV’s roof eliminating leak points.

Third, durability. These panels are also military grade and should take the beating that many RV solar panels take because of branches, and vibrations of just going down the road.

Now these panels do have their drawbacks as well, the biggest of which is heat dissipation.  Hot solar panels preform worse, and being stuck to the roof with no airflow these can get very hot.  They can also dissipate that heat into the RV making your living space hotter. 

The second biggest drawback is the cost as these panels are more expensive than a similar glass solar panel alternative or even some other flexible competitors. As with any system, the drawbacks must be weighed against the positives for your situation.

As we test the system more, we will elaborate on the pros and cons of these panels, but so far we have been loving their look and their performance!

We split our combiner box into 3 busbars to handle the 3 solar circuits.
With 2 panels in series and the rest in parallel our Open circuit voltage off the roof was a bit over 50 volts.

We wired all the panels in a series parallel configuration and utilized a special combiner box on the roof that allowed us to wire them in three separate circuits.  From here the wires ran down to the electronics.

Inverter, Charge Controllers, and the Brains

Solar panels cannot be connected to the batteries directly and need a special charge controller installed between them and the batteries.

This is because the panels power output will differ from what the RV batteries require for charging and this device converts it to the appropriate level and optimizes solar panel efficiency. 

With our Ultimate RV Solar install having so much solar power, we needed to use three separate charge controllers to handle the load and to make the system more efficient.

We installed 3 Victron Smart Solar MPPT 100|50 charge controllers.

3 Victron 100 Volt | 50AMP charge controllers for the solar. Disconnects on the left and fuses on the right side.

Partial shading and different lighting conditions on some panels and not others – like we have on the front cap panel set – can negatively impact the performance of other panels on the same charge controller, but keeping them on their own controller prevents this making the system more efficient.

Connected to the battery are the RVs loads and typically an Inverter to convert the DC battery power to typical residential AC power.

Our past install utilized a Victron 3000VA inverter and for this build we upsized it to a 5000Va Unit.  (VA stands for Volt Amps and is a unit of power used for alternating current, similar to watts)     This larger inverter can provide a lot of power to be able to run multiple large appliances at once including the air conditioner and really helps to make it feel like we are hooked up to the grid all the time.  We can run the microwave and instant pot and at the same time, no problem! ​

The new 5K VA inverter installed underneath the batteries.

After installing the inverter there were only a handful of components left to install.  First the DC-DC converter that changes the 24 volts of this battery bank to 12 volts that the RV’s DC appliances and lights use.  Our first install was a 24 volt system so this was not a change for us and we were able to re-use the same Victron Orion converter we had used before.

We have been using the Victron Orion 40 AMP converter and we re-used it for this system Lastly, we installed components that would monitor the system and allow us make changes to its performance remotely.  A battery monitor is essential in an ultimate off-grid system as it gives an accurate reading of the state of charge of the batteries

  We used the Victron BMV712 battery monitor. ​The BMV712 is a 2-part meter that includes a shunt installed on the negative lead of the power system and this internal display unit installed in the RV. For our Ultimate System we also installed a computer called the Octo GX that is designed to communicate with the inverter, charge controllers, and battery monitor to wirelessly communicate the systems data with an online portal.

This allows us to see how the system is functioning on a phone or computer as it shows solar energy, battery state of charge, AC and DC power and how it is flowing.

It also sends this data to the Victron VRM Portal that allows us to log into the system remotely and see its performance real time. Here we are able to easily make programming changes to the system – we will be sharing what we utilized this for in an upcoming articles and videos. 

The Octo GX unit we are using as the brains of the system, it has no display but connects wirelessly to a phone or computer Below you will find a summary of the changes we made.  Note the weights of the system components as this was a huge factor for us.  We only had about 150lbs additional weight we would allow for this system and when all was said and done we came out only around 110 lbs heavier overall which we are thrilled with since we increased capacity 3X on both RV solar panels and batteries!  

  Click here to see the list of system components:


Performance

We have been operating this system since June 2020 and things have been working great. 

We have traveled with this system over 3000 miles and all the connections to the batteries and electronics are still tight and all the panels are staying well adhered so were very happy about that!  

With the larger inverter we have been able to run multiple large loads, like cooking appliances, hair dryers and even the air conditioner we have run a bit on sunny days, without worrying about overloading it.

It really feels like we are living with the RV hooked up to shore power all the time.  We are also loving having the system connected online so we can monitor its performance.  ​

Data Data Data!  This is the dashboard for the Victron VRM portal that the Octo GX sends data to and can be accessed online. We will be sharing lots more about the performance of the system in the future. Overall, we are seeing daily power output in full sun between 1600 and 1800 Watts but have seen peaks upwards of 2300 Watts.

A lot of that power loss we believe is due to heat on the panels and will elaborate of this in a future post.

Front Panel Performance in Summer & Winter

What about those front solar panels?

While at first glance they may seem impractical, there is a method to our madness. You see, as full-time RVers, we chase 70 degrees and stay in our RV year-round. In the wintertime, the sun’s angle is much lower in the sky. The steep angle of the front camp, while a disadvantage in the summertime, is an advantage in the winter.

Let’s look at some numbers:

Panel
Section
Summer Peak
Performance*
Winter Peak
Performance**
Difference
Front Panels200W/460W = 43.5%340W/460W = 73.9%+30.4%
Roof Panels1500W/2300W = 65.2%1020W/2300W = 44.3%-20.9%
Total System1700W/2760W = 61.6%1360W/2760W = 49.3%-12.6%
*Sunny July Day in Michigan data; **Sunny December Day in Arizona data

In both instances, the nose of the RV was pointed directly south. One was in Michigan (summer) and one was in Arizona (winter).

Based on the data above, we see a few interesting things happening.

First, the winter peak performance of the front panels increased 30%!

Second, the roof panel performance decreases by 20%.

Third, the performance percentage of the front panels in winter exceeds the peak performance of the roof panels in summer. This is because while we have more direct and powerful sunlight in summer, the temperatures are higher – the panels can get upwards of 160 degrees F! This decreases the overall performance of the panels in summer.

More data and analyses coming soon!

Overall Takeaway

The best thing about the panels, however, is the weight and how that enabled us to put so much power on this RV’s roof.  Before finding these panels, we didn’t want to use flexible lightweight RV solar panels but now we are confident they will last. We have been able to max out the generation capacity off this 32 foot RV’s roof, hence why this is our Ultimate RV Off-Grid Solar install.            

Cost of the System?

So a huge question we get asked is: what did it cost?  Considering we did all the work ourselves the components for this system would come in around $17,000 retail. 

This may seem like a lot to spend on a power system in an RV, but there are a lot of factors to consider in the investment so why might you do this.

For us, this is our home and we have no plans to leave the RV. So to have the amazing benefits that come along with not having to worry about power anywhere we go is huge for us. Solar power has changed our mobile lifestyle for the better and we couldn’t imagine not having it now.  

We also have property that does not have power pulled to it.  To get the utility to pull power from the road would cost more than $20,000 – so that right there makes it worth it!  We can have power on our off-grid spot and take it with us, too!

Why do we need such a large RV Solar System? ​

Well, we hate running our generator. We love the silence and ease of this system, and we love not worrying about having enough power or battery capacity.

That said, this system is oversized for our average daily power need, but this really helps with multiple cloudy days in a row or the shoulder and winter seasons when we don’t get as much sun.

The system is also large enough that on very hot summer days we can run the air conditioner on solar power to break the heat – a huge plus!

Tom scrubbing bugs off the front cap solar panels while traveling. We fill fuel at truck stops frequently and the semi window washer wands work well!

The trick is that when we don’t have a big electrical load and the batteries get fully charged that the power goes unused…unless we find something else to store it in.

Charging an Electric Car with Solar Power

We decided to dump the excess solar energy into a plug-in hybrid/electric car. Read all about how we did it here.

What’s Next?

If you’re interested in the specific details of this particular installation, watch out on our YouTube channel for the next video in the series where we dive deep into what an install like this takes. ​

Also, join our newsletter below to learn when we post more about this system, as we are not done playing and fully testing it out yet! We’ve got lots more data and performance specs to share.  

Read the latest:

Mortons on the Move

We are Tom & Caitlin Morton. We gave up the stationary life for one where we are constantly on the move. We live in a fifth wheel RV and travel with our two pups, Mocha and Bella. We enjoy hiking, biking, boondocking, videography, and upgrading our RV to suit our off-grid mobile lifestyle. Our goal is to share educational, entertaining, and inspiring content with our readers and viewers.

View Comments

  • I 'm watching carefully. Getting ready to outfit our new 40 foot solitude so we can stay out of the pay big bucks per night to get electricity world. Looks like your system is worth following.

  • Like the new setup Tom! If you haven't yet disposed of your old system components, I'd be interested in purchasing some of the superseded items to beef up my Tesla module battery bank system.

  • Tom & Cait
    Very impressed with the thought that has gone into this and the quality of the install. In terms of cost savings, in addition to eliminating the cost of pulling power to a stationary home, avoiding nightly charges at an RV park, eliminate cost of a diesel genset & diesel usage etc.
    But the most importantly, in the midst of CovID19 your solar generator will allow you stay clear of crowds. Eagerly looking forward to your adventures.

  • Hi Tom,
    You state above that the 8 batteries have 11,200 equiv. Watt- hours which would mean each battery has 1,400 W-hr. Is Battle Born understating the power storage of their batteries by 20%? 100A-h *12V is only 1,200 W-h. Is their average voltage during actually higher than 12V and the 100 A-h perhaps a bit conservative as well?
    I contacted them for some tech info many months ago and they really don't seem to have a really tech competent person on staff. They were very friendly and responsive but could not provide the answers I was looking for at the time.
    Thanks for sharing your very well executed project.

  • May I simply just say what a relief to find somebody that actually
    understands what they are discussing on the
    web. You actually realize how to bring an issue to light and make it important.
    More people should check this out and understand this side of your story.
    It's surprising you are not more popular given that you certainly possess the gift.

  • Hi Tom,
    We purchased a new Jayco North Point fifth wheel this last June. While it has been “pre-wired” for solar and generator, I have not not purchased either until we went out with it and experimented in the clamp grounds a little - as we did earlier this year. We do want to go boon docking. Planning on outfitting it with panels and batteries sometime this next year, and currently looking at options. You got my attention earlier relative to your design involving the Tesla battery and I’m still interested in it as part of a solar design for our fifth wheel. Also tracking your latest design with Battle Born batteries and solar panels. With that said, are you aware of the EVTV Motor Verks PowerSafe 15? If so, interested in your thought’s on it? The performance vs the price? They stacked 3 Tesla Model 3 batteries into a single box, complete with battery management and a 6KW DC-AC pure sine wave inverter/charger. Apparently built specifically for RV and marine applications. I’m also interested in the actual Battle Born battery performance data. Doesn’t seem to line up with the 11,200 WH estimate you came up with? I liked your design including, and info on the new BB flexible solar panels. Trying to find more info online now. Big benefit for not poking a bunch of holes in the roof...

    • Very exciting! Yes, I am familiar with EVTV. I have not worked with them or their stuff, but they seem to know what they are doing. For the price that is an amazing product and I feel like they have implemented it safely. As for the BB real-world data is coming VERY soon! We did some laboratory testing that explains how we got 11.2 Kwh out the 8 batteries... more on that soon! :)

  • Tom,
    My wife and I are your biggest fans and have learned so much from you and Cait. We are planning a trip into Canada starting at end of July thru first part of September.
    We have on order a new RV, our 6th in 20 years.Our new RV is a Living Vehicle. They make 3 models and ours is the PRO and has the following Solar and Power setup:
    Living Vehicle® PRO energy system
    - Power supply 52-volt input 14V output at 40 amps
    - Dual 8M VSP 8 Module Case energy packs
    - 48 kW energy storage using automotive grade energy backs using nickel manganese cobalt technology
    - 8,000 Watt hybrid inverter with continuous 120V AC
    - 3,080 watts of total solar power
    Solar Awning package included as standard equipment with additional roof mounted panels
    High-Capacity Axles with electric over hydraulic disc brakes
    PRO Pro Black Treatment protective spray along chassis
    PRO-HD frame and running gear. 18,000 lbs. GVWR
    4-Wheel Electric-Hydraulic Disc Brakes
    Automatic Leveling
    Would really like your comments as to this model's solar setup, as you wear your Electrical Engineering hat.:)
    If you will, look Living Vehicle and read more about this RV. They make 25 per year and we are waiting for ours, which will take 9 months to take delivery.
    Thank you in advance for your comments.
    Malcolm

    • That sounds like an incredible system! I am not familiar with those trailers so will look into them. From a high-level perspective that seems like a well-balanced system with enormous battery capacity. It would need to be a very custom system with a well designed BMS to make those batteries safe, but if done properly sounds amazing! I will need to take a closer look at them!

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