Owlbear Solar and Electrical Use Case

Unleashing the Power of Solar and Battery Systems: A Use Case for Electric Consumption in RVs

As the world moves towards sustainable living, more and more people are turning to renewable energy sources like solar power to meet their energy needs. This shift towards clean energy is also evident in the recreational vehicle (RV) industry, with RV owners increasingly exploring the use of solar and battery systems to power their adventures on the road. In this blog post, we will delve into the development of a use case for electric consumption, specifically for the specing of a solar and battery system in an RV.

Why Go Solar in an RV?

RVs are a popular choice for travelers who seek the freedom of the open road and the ability to explore new destinations at their own pace. However, traditional sources of power in RVs, such as generators or relying solely on the RV’s engine, come with their drawbacks. Generators can be noisy, require fuel, and emit harmful emissions, while running the engine for prolonged periods can lead to increased fuel consumption and wear and tear on the engine. This is where solar power can be a game-changer for RV owners.

Harnessing the sun’s energy through solar panels on the roof of an RV can provide a reliable and sustainable source of power. Additionally, coupling solar panels with battery storage allows for energy to be stored and used even when the sun is not shining, providing power during cloudy days or at night. This combination of solar and battery systems allows RV owners to enjoy the benefits of clean and quiet energy, while also reducing their environmental impact and saving on fuel costs.

Developing a Use Case for Electric Consumption

When it comes to specing a solar and battery system for an RV, it’s crucial to develop a comprehensive use case that takes into account the specific electric consumption requirements of your RV. Here are some steps to guide you through the process:

  1. Assess Your Energy Needs: Start by evaluating your RV’s energy consumption requirements. Consider the appliances, devices, and systems that you will be using in your RV, such as lights, refrigerator, air conditioner, water pump, and entertainment systems. Note down their power ratings, usage patterns, and estimated daily energy consumption.
  2. Determine Your Solar Panel Capacity: Once you have a clear understanding of your RV’s energy needs, you can calculate the solar panel capacity required to meet those needs. Consider factors such as the location and orientation of your RV during travel and camping, the average daily solar insolation in those locations, and the efficiency of the solar panels you plan to use. You can use online solar calculators or consult with solar experts to determine the optimal solar panel capacity for your RV.
  3. Choose the Right Battery System: Selecting the right battery system is crucial for storing and utilizing the solar energy efficiently. Consider the capacity, type, and voltage of the batteries based on your energy requirements and the available space in your RV for installation. Lithium-ion batteries are a popular choice due to their high energy density, longer lifespan, and lighter weight compared to traditional lead-acid batteries.
  4. Plan for System Integration: Once you have determined the optimal solar panel capacity and battery system for your RV, it’s essential to plan for their integration into your RV’s electrical system. Consult with a qualified electrician or solar installer to ensure the safe and efficient installation of the solar panels, charge controller, inverter, and battery system. Consider factors such as wiring, mounting, and protection against overcharging, over-discharging, and other electrical hazards.
  5. Monitor and Optimize Your System: After your solar and battery system is installed, it’s crucial to monitor and optimize its performance regularly. Keep track of your RV’s energy consumption and the performance of your solar panels and battery system. Make adjustments as needed to optimize the system.

This Specific Use Case

It took us about four months to develop a use case that was workable. Some of the challenges were changing expectations of what is possible and normal, and personal behaviors of consumption, and maintenance. A simple difference between home vs RV life is that at home, people typically let the faucet run while brushing your teeth, where as in an RV with only 50 gallons of fresh water and perhaps days until you’re at a place where you can refill, the behavior is modified to just get the brush wet or use a glass of water for the whole process. The same goes for electricity. Turn things off while not using them, turn the heat down, turn the cooling up, etc.

In the end, it was decided upon the following:

  • Batteries should have enough capacity for three days without sun.
  • Air Conditioning could only be run for short periods of time on batteries to initially cool the area.
  • Install more efficient air-movers to help circulate warm and cool air.
  • Technology such as internet, monitors, etc. are required and thus their consumption 24×7 must be taken into account
  • Solar panels should recharge a minimum of 30% batteries in six hours of good sun.
  • The Inverter should be able to run everything in the trailer, not all at once, but at a minimum, all minor loads and one major load such as the air conditioner, microwave, or electric heater.



It was decided to go with a 24v system. There are advantages and disadvantages with this. The primary advantage is efficiency and lower current. Following Ohm’s law, V * I = P where V is volts (the amount of electricity), I = current or amperage (the flow of that electricity), and P for power in watts (the amount of work that the supplied electricity can do). So increasing the voltage from 12 to 24 volts, in turns reduces the current by half while still providing the same amount of power.

The number of batteries, it was decided, were six 100ah @ 12v Battle Born LiFEPO4 batteries. These are arguably at the top of the industry, much of the price of them is for the name. But they work, and that was very important to GLRay. These batteries (more tech talk) were to be configured in three parallel lines of two batteries in series – yeah, it’s a mouthful and the head needs to be wrapped around that. Basically it means that the two batteries in series will bump the voltage up to 24v. You put three of these series together in parallel and that changes to available amperage up to a whopping 300/600 amps. Not that this system would ever use that, but hey… it’s available. We actually limited it to 200amps, as there is nothing in the trailer that would ever exceed that – not even if all of the loads were turned on at the same time.

These batteries will provide 300ah @ 24v of power or 7.2kwh. That’s a lot of power, but not enough to run air conditioners all day long.

Solar Panels

As the use case stated, we needed the batteries to be charged a minimum of 30% in six good sun hours. That would call for a minimum of 450w of solar panels on the roof. That would be the bare minimums. There is also an arbitrary rule of thumb ration of ah@12v : 2x w for batteries:solar. So for this ratio, for the 300ah @ 24 or 600ah @ 12v, we would need 1200w on the roof. Since solar panels are inexpensive, we went this route. We have six 200w panels on the roof feeding the batteries and they generate quite a bit of power.

System Components

Since I have experience with Victron Energy components in El Alebrije, we decided to go with Victron all around – well… almost.

The SmartSolar MPPT controller is a 150/70. What this means is that on the input side, it can convert up to 150v, and on the output side, it can convert up to 70amps to charge the batteries. So min-maxed this SmartController could support up to 2000w of panels on the roof. We only put 1200w up there – so room to expend if we need to.

The next thing would be the Orion DC-DC charger. This device functions to take the 24v battery power and convert it to 12v for the trailer. All of the components in the trailer are 12v. This is a little bit of added complexity, but the trailer would always have the required voltage to run everything there – without having to worry about the voltage fluctuation of drawing directly from a 12v source.

Next is the brain of the system – the Victron MultiPlus-II 24/3000 2x120v. That’s a mouthful. This device is both an inverter and a charger. It will take shore or generator AC power and convert it to DC @ 24v to charge the batteries. It will also take the 24v DC power and invert it to 120v AC to power things like the air conditioners, the microwave, and laptop chargers.

System Monitor

The system monitor is a display or UI that is installed in the trailer and relays pertinent information regarding the electrical system, holding tanks, and temperatures to the user. This is important for a variety of reasons, primarily to give information and knowledge. And as we all know, informed people and knowledge lead to power. With this information, we are able to adjust behaviors, change itineraries, etc. Without it, we would be surprised when we ran out of power or water – which would be a bad thing.

We chose to go with the Simarine Pico Blue. Made is Slovakia, they primarily focus on leisure water craft. It’s a pretty nice system, although there are some software issues – which, with time, are getting remedied.

Ironically, the main issue on the maiden voyage had to do with the Pico not reporting correct SOC (State of Charge) for the batteries, thus giving false information and a false sense of security – and a bit of frustration. That problem was fixed right away.

2022 Apple Harvest and Pressing

It’s that time of year again. 600lbs of apples sweating in the garage for a few weeks. Crush will be In a week or so. Then followed by pressing and a couple of bottles of sweat cider, and the rest to fermentation.

Last year my yield was low, I hope to double or triple it through a different crush process this year.

Since I made a new masher, I was able to double the yield from 2021. We got about 35gal of juice this year. Enough to make four different varieties and have a bit of simple cider left over to give away.

We had four varieties this year:

  • Pippin Crisp – a single varietal cider. Quite sour but is mellowing with time.
  • Just Cider – a multi varietal cider. Unfortunately this cider didn’t have enough sugar for the yeast and it became stressed and ended up being drinkable-but-funky
  • Guava Treat – a multi varietal cider back sweetened with guava nectar. Turned out quite nice with fruity hints of guava – not not to sweet.
  • Holiday Spice – the same multi-varietal cider back sweetened with holiday spices. This too was quite delicious and is getting better with time.

Apple Pressing

We (me) couldn’t wait two weeks for the apples to sweat. Good that we moved on it now, the apples were perfect.

We used 4 bushels of Gravenstein, one of Whitney crab apple and one of mixed apples consisting of honey crisp, snow and jazz apples.

Today we processed six bushels of apples – about 240lbs. Washed, de-wormed, cut rotten sections out, ground, pressed and… enjoyed fresh unadulterated apple juice.

We got about six gallons of juice, 5.5 is prepped for fermentation while we are enjoying the other half gallon just to sip now.

Acids were at .775% so we brought it down to .65% Sugars were at 15%

Tomorrow morning we will put the yeast in and the fermentation will commence.

Between all of the prep, processing and cleaning, it was a good 5-6 hours. But we had a good time.

1-2 weeks after the yeast goes in, we move it to secondary fermentation where it will sit for 4-6 months. Then on to bottling and another fermentation for another 4-6 months. This time next year we will be enjoying our first batch of cider.

Apple Harvest

Getting close to pressing. Waiting two weeks to sweat the apples for flavor – although the three bushels we collected today and one yesterday are probably ready to press now.

Fermentation stage one will take 1-2 weeks and then another four months for stage two and clarification. Then to bottling for 6-12 months. Once of the downfalls of a new cider maker is the impatience. We will have to see how long I last.

What to do with all of the apples?

On to another adventure.

Since we live in Sonoma County, every summer & fall, it’s harvest season for apples. Gravensteins are the locally known varietal with significant influance from the famed botanist Luther Burbank.

That paired with my love for hard cider, we will be pressing apples this year. Last year I made a press with some plastic buckets and while it worked, it was messy.

This year, we have a propper fruit press and are planning the harvest and processing appropriately with dedicated gear and space.

One of our trees is an early variety of Whitney crab apple – deliciously crisp with the tight balance of tartness and sugars which we harvested today We go 40lbs from a five foot tree – leaving a few apples for the birds.

We have also sources through friends 300lbs or so of apples of different varieties to harvest later in the season.

The apples are now in storage to build some additional sugars and then to pressing.