Read More About Our Setup
We’ve chosen to live the RV life because we want the freedom and flexibility to go where we want, when we want. But what good is that freedom if we’re tethered to RV campgrounds at $35 bucks per night? After all, even the most robust mobile Internet setup needs power to run.
So, how can we reclaim our freedom without living in the Dark Ages?
How about a generator?
One solution is to get a generator that’s big enough to power our RV off the grid. And we did that, purchasing the 3500W Harbor Freight Predator.
It runs at just 57 dB, which is incredibly quiet, and is rated at 2800 running watts and 4000 surge watts. That gives us about 24 amps of current with the ability to surge up to 33 amps. Our RV hooks up to 30 amp shore power, so we can run basically everything using the Predator generator.
Generators are great because they can stand in for shore power (if you get a big enough one) but they come with two big disadvantages:
Disadvantage 1: They’re loud
When I said our 57 dB generator is quiet, I meant by generator standards. It’s still a generator and it’s still loud. When we boondock in Wal-Mart parking lots or stay in no-hookup sites at campgrounds, proper RV etiquette dictates we don’t run our generator 24/7. That means one of two things:
- We have no power when we boondock at Wal-Mart, or
- We don’t boondock at Wal-Mart.
Well, why don’t we just stay at campgrounds? First, the aforementioned inconvenience of having to jump constantly from campground to campground. Second, that’s a recurring cost we don’t want to deal with. At $35 per night, one month’s worth of campground stays is $1,050. That’s money right down the drain that we’ll never get more utility out of.
Plus, many campgrounds won’t let you run a generator or restrict the hours during which you can use it.
Disadvantage 2: They need fuel to run
Our generator has a 2.6-gallon gas tank and is rated to run 11 hours at 25% capacity–about 700 watts AC or 6 amps at any given time. Well, guess what? If we run our LED living room lights and charge both laptops, that’s 6 amps of current right there. If we do anything else, we’re way over it. And that means our 11 hour run time decreases.
I’d estimate our generator runs for about eight hours with our normal power usage, which means we’ll need at least 2.6 gallons of fuel per day. (I’ll assume we’re out hiking or something for a large portion of the day, and we can power everything down at night when we sleep.)
There are two downsides here.
First, our 5-gallon gas can only has enough capacity to run the generator for two days with our typical usage. If we’re off the grid for a few days, we may need more fuel. That means carrying more with us at all times or going to a gas station.
Note: Some generators have the ability to run off propane, which is a great way to mitigate this annoyance.
Second, at $2.75 per gallon of gas, that’s $7.15 worth of fuel each day, or about $2,600 per year.
Generators don’t last forever; depending on the model, you can expect to get 3,000-5,000 hours of run-time. If you run it eight hours per day for a year, that’s 2,920 hours. You’ll have to get a new generator every year! (Especially if you buy discounted as we did with the Harbor Freight model.)
So, now you’re repeatedly inconveniencing yourself for fuel, incurring huge expenses, and ticking off everyone around you.
There’s no way I’d want a generator to be my only source of off-grid power. That leaves solar.
Why we love our solar system
(And no, I don’t mean this solar system, though we do love that, too.)
With our solar setup, we can boondock to our hearts’ delights. The only thing really limiting how long we can stay off the grid is the capacity of our fresh, gray, and black water tanks.
Our system is comprised of the following:
- 4 x 98W solar panels (392W total)
- 2 x 300Ah 6V AGM batteries wired in series to 300 Ah and 12V
- 30A Victron SmartSolar MPPT charge controller with Bluetooth
- Victron BMV-712 battery monitor with Bluetooth
- Victron Multiplus Compact 2000W pure sine wave inverter
It’s actually the Adventurer solar kit from AM Solar, except we swapped out the 200Ah lithium batteries for 300Ah AGM batteries. This gives us about 40A more usable capacity for about $800 less.
AGM batteries have a depth-of-discharge of up to 80%, which means our 300Ah setup gives us 240Ah usable capacity. Our typical usage is about 75-90Ah per day, depending on how much time we spend in the RV. That means we get about three days from our batteries if we never recharged them at all.
But the solar panels do the recharging for us. A good rule of thumb is that a single solar panel will provide four times the power it’s rated for in a single sunny day. For our 392W setup, that means a typical day will give us nearly 1,600Wh of power.
Note: Watts (W) and amps (A) are instantaneous rate measurements meaning they apply to a single point in time. Watt-hours (Wh) and amp-hours (Ah) are volume measurements. If you run a 1000W TV for two hours, that’s 2000Wh of power used. The 1000W measurement is how much power the TV is using at a moment in time whereas the 2000Wh is how much total power it used while being operated.
How many Ah is that? Ohm’s Law dictates that Current (Amps) = Power (Watts) / Voltage (Volts). Our panels put out about 20.5V, which means they’re able to store about 78Ah per day (because 78Ah = 1600Wh / 20.5V).
So, in a typical sunny day our solar panels recharge a similar amount to what we use. This lets us stay off the grid as long as our tanks will let us.
But it isn’t always sunny. In fact, the last few days have been partly cloudy, and we’re parked under some trees. As a result, we haven’t been hitting that 1600Wh per day estimate. Instead, we’ve had 780Wh, 1120Wh, and 780Wh over the last three days.
Over the last three days we’ve only replaced about 130Ah in our battery bank despite using over 200Ah. This isn’t sustainable for the long term.
Thankfully, our batteries also recharge when we drive our truck and RV to the tune of about 3A per hour. On days when we drive for five hours, that’s 15Ah of capacity, or 5% of our battery bank.
Should we get into a pinch where a string of bad weather days leave us unable to recharge sufficiently, we can also plug into either shore power or our generator to power the RV and charge the batteries.
We haven’t had to do this yet despite some really cloudy days. In our first three weeks on the road, we stayed at campgrounds for just six nights while spending 15 nights off the grid. That’s over 70% of our nights for free, a savings of about $525.
That begs the question, what’s the return on investment (ROI) on our solar setup?
Is solar worth the upfront cost?
For us, unequivocally yes.
Our solar setup cost about $5,500. That includes the cost of the Adventurer kit from AM Solar, plus some tools and extra cables that we had to buy (because we’re solar novices with only passing experience with electrical stuff).
Note: We installed everything ourselves, which took 10 days and 80 hours of my dad and I getting some real good father-son bonding time. And that’s just build time and doesn’t include research. AM Solar will install the system for you at an additional expense of about $6,000, which just means your breakeven point moves further out.
To break even we need to sleep off the grid (cost-free) for 157 nights, assuming an average cost of $35 per night. If we stay in campgrounds for two nights per week and boondock for the other five, we’ll break even on our solar investment in 31.4 weeks, or just under eight months.
Considering we plan to full-time for longer than that, solar was a no-brainer investment for us.
Snapshots of our solar setup
We installed the panels on the rear of our RV roof, as shown below.
Each panel is rated at 98W, but I’ve seen our solar output hit 420W or 105W per panel. These panels are manufactured by Zamp Solar, and they say each will perform better than 98W in optimal conditions.
Three other things to note in the image above:
- The black box in the middle of the panels is our solar combiner box. All panels are wired into that box in parallel.
- The crude white tape on the roof is Eternabond and it secures the loose cables to the roof.
- The black and orange cables run into the RV’s front storage compartment about 27 feet away where they connect to our solar controller.
Just like our mobile Internet installation, we ran the cables through the refrigerator vent and didn’t need to drill any holes in the roof, save for the ones to install the panels.
We did have to drill several holes between the various sub-floor storage compartments in order to feed cables everywhere.
Here’s what the front storage compartment looks like now:
1. Victron Multiplus Compact 2000 W Pure Sine Wave Inverter // Inverts the 12V direct current (DC) supplied by the battery to 120V alternating current (AC), which is required to run appliances from wall outlets. We can run up to 2000W at any one time. When plugged into shore power or a generator, this inverter also regulates the flow of current into the battery bank, allowing us to recharge the system safely.
2. 300A Class T Fuse With Breaker // Used as circuit protection between the inverter (1) and battery bank (4).
3. 40A DC Breaker // Used as circuit protection between the battery bank (4) and solar controller (6).
4. 300Ah AGM Battery Bank // What we run our entire RV off and what the solar panels charge up. Has the capacity for about three days off the grid if we never charged them up.
5. Victron BMV-712 Battery Monitor // Reads battery voltage to estimate how many Ah have been used and transmits that information via RJ45 cable to an interface we installed in the living room of the RV.
6. 30A Victron SmartSolar MPPT Charge Controller // Connects the solar panels on the roof and the battery bank (4) and intelligently regulates the flow of voltage into the batteries to prevent overcharging. Also connects to a Bluetooth dongle pictured below the number 6 (and above the number 7), which allows us to monitor both real time and historic solar output as shown in a screenshot above.
7. TireMinder TPMS Signal Booster // Not a part of the solar setup at all, but I wanted to call it out to avoid confusion in the image above. This two-pronged, wall-mounted device is a signal booster for our Tire Pressure Monitoring System (TPMS) that alerts us to any changes in tire pressure and temperature before bad things happen.
8. Empty Battery Box // The box where the stock lead-acid battery for the RV was housed. It’s no longer used and sits there empty.
You’ll also see three small red boxes, which I didn’t call out. Those are disconnect switches, which allow us to easily cut power at key points in the system. From left to right in the image above:
- Between the inverter (1) and the battery bank (4)
- Between the battery bank (4) and the rest of the 12V DC circuit (e.g. water pump)
- Between the solar panels and the solar controller (6)
Both our inverter (1) and battery monitor (5) are connected to interfaces about 10 feet away inside the living space of the RV.
The top interface is for our battery monitor. It tells us how full the batteries are, what our real-time draw is, and instantaneous battery temperature and voltage. I check this monitor about 10 times per day, mostly because I’m obsessed with numbers and enjoy seeing the readings change as we use more/less energy.
The bottom interface is the control panel for our inverter. When we’re plugged into shore power or a generator, the LEDs on the left side of the panel (under “charger”) light up. As you can see, right now we’re plugged into shore power and our inverter is allowing float charge into our battery bank. When we’re off the grid, the LEDs on the right side (under “inverter”) light up if there are any warnings.
Oh, and this stuff is heavy
This system has some serious heft, most notably from the batteries. All told, I estimate we added nearly 350 lbs to our fifth wheel:
- 60 lbs of solar panels (4 x 15 lbs)
- 186 lbs of batteries (2 x 93 lbs)
- 25 lbs of inverter (1 x 25 lbs)
- 30 lbs of cables and wire
- 40 lbs of plywood
Our fifth wheel can hold up to 4,400 lbs of gear, liquids, and other stuff, which we won’t get close to exceeding. Our truck will be able to handle the extra weight, too. You can read more about our truck and RV setup here.
Snapshots of the installation process
It took 10 days and about 80 hours to install our solar system. Here are some snapshots of our progress along the way.
In the end this solar setup has completely transformed how we live in our RV. We have the freedom to go anywhere we want without being tied to 30A outlets at RV parks. The only thing that stops us is Internet connectivity, but we can just plan our in-the-boonies trips for the days we don’t have scheduled work.
Again, we are not solar experts. I’m a total electrical novice, and my dad has just intermediate knowledge from his life experience. Ultimately we watched a ton of YouTube videos, studied wiring diagrams, and purchased a kit with everything included.
Speaking of the kit…
Would I recommend purchasing a solar kit from AM Solar?
Yes. In the end, we paid more going with the AM Solar Adventurer kit than if we had piecemealed everything. We probably could have built this system for $4,000 if we were willing to buy everything separately and go with lower quality parts in some spots (like a modified sine wave inverter instead of a pure sine wave inverter).
But solar isn’t something we wanted to skimp on. With AM Solar we get top-of-the-line parts, great customer service that was willing to help us when we called, and a ton of wiring diagrams specific to our kit.
That last one was crucial and shouldn’t be undervalued. A great wiring diagram is gold, and AM Solar’s documentation was incredible. I’d recommend them to anyone looking to do their first solar installation.