Detailed Look at Our DIY RV Boondocking Power System

We love to travel the Southwest US during the winter. Camping out on BLM land, exploring wildlife refuges and State/National parks. This means camping off the grid without electrical hookups. Some sort of boondocking power system is essential if we want to camp more than a couple days.

We started out using a 2000 watt Champion generator to keep our batteries charged. It worked fine but even being a quiet inverter style unit it still had an annoying drone and needed to be filled routinely with fuel. At 48 lbs it’s also not the lightest thing to move around.

About a year and a half ago I decided to install some solar panels and build up a decent boondocking power system for our Cougar fifth wheel trailer. Since we are full-time RVers and need to be frugal to keep it that way I had to build slowly. I added pieces and made improvements as I could afford them.

Boondocked in California near Yuma AZ

If you have followed the blog for a while, you’ve likely seen some of these upgrades. Up until now, they have been published as a string of separate posts and videos. Now that I feel I have my off grid RV power system complete I’m putting out a detailed overview of the system, the components used and how much they cost. Luckily for me, labor was free as I did all the work myself with the odd bit of help from friends.

Disclaimer: Working with electricity can be dangerous. Performing the modifications detailed in this blog posting may void your warranty. The following is for educational and entertainment purposes only and should not be taken as instructional. If you decide to do the same modifications I’ve done then research and beware of the risks involved. I accept no liability. You have been warned! – Ray

System Components Explained

Click the Headings or Photos for more in-depth installation info on each.

Battery Bank

The heart of any RV boondocking system is the battery bank. I chose to go with a tried and true power source. Four big 6-volt lead acid batteries with a total capacity of 464 amp hours. Although they require extra maintenance versus other types plus good ventilation, I find them to be a great bang for my buck. Maintenance isn’t a problem for me, and the trailer’s front storage compartment, where I’ve installed the battery bank, has abundant fresh air flow.

Four Interstate 6 volt batteries

I found the plastic box to house the batteries at a local marine parts store. It fit the compartment floor width perfectly and came with a lid, and the wire holes precut. I just had to add ventilation holes to the bottom and top of the battery box.

Battery System Monitor

Next, to keep tabs on my power bank, I installed a sophisticated battery monitor. I picked a well thought of unit from Bogart Engineering called the Trimetric TM2030-RV. The Trimetric keeps a record of the current flowing into and out of the batteries and monitors the precise voltage of the bank. Then it calculates the percentage of charge left.

Trimetric Meter and Shunt installed

I’d advise a battery monitor as one of the first upgrades to make. It will give you an idea of your daily power usage so you can figure out how much solar will be required when the time comes.

1000 Watt Power Inverter

All boondockers need a power inverter if they want to run any items that use 120 volt AC power. Like things you would plug into a regular household power outlet. We decided on a 1000 watt unit as our AC power demands were relatively meager compared to others.

We don’t usually run any high wattage items such as the coffee maker, microwave or toaster when boondocked. If we ever do desire to use those, I’ll fire the portable gas generator for the brief task.

1000 Watt Inverter install

The cost was a significant consideration. The difference between a 2000 watt inverter and a 1000 watt unit is substantial. We did spend the extra dollars for a “pure sine wave” inverter because it would be powering our sensitive electronics. My name would be mud if I blew up my wife’s iMac. 😉

 500 Watt Solar Panel Array

I started out with a 200 watt Renogy solar kit to get my feet wet. It proved to be a decent little system, especially for the money spent. If we avoided using our 43″ TV and Anne’s 21″ computer we could get by, but a little more wattage would be nice. So, I added two more Renogy 100 watt panels on the Cougar’s roof last December and recently added a 100-watt remote ground panel. Yay!

5 100 watts solar panels

With the 500 watts of solar panels, I’m now seeing 25-30 amps of current flowing into the batteries during peak sun hours. Should be plenty for our particular boondocking power needs.

Solar Charge Controller

You will hear many different opinions on charge controllers with most folks flat out stating that an MPPT controller is the only way to go. I guess I’m a bit of a contrarian and went with a PWM type unit from Bogart Engineering.

Bogart SC2030 solar charge controller

I believe it was the best way to spend my money. I envisioned my system staying in the smaller 400-500 watt range and being a tinkerer wanted full control over the way the solar controller charged my battery bank. IMHO the SC2030 controller when mated with the companion Trimetric monitor, fits the bill perfectly for me.

(For more information on my choice of a PWM over an MPPT type controller check out section C1 of the Bogart Engineering FAQ)

InteliPower Battery Charger

Solar power is incredible, and I love it, but unfortunately, the sun doesn’t always shine. Get too many cloudy, dry camping days in a row and even our large battery bank runs down. Then, out comes the gas generator to top up it up.

Once I had installed the Trimetric battery monitor, I quickly realized how pathetic the OEM converter was at recharging the batteries. It was taking forever, wasting my time and fuel, not to mention the extended periods of noise pollution. It would start at a relatively high charge rate but would quickly drop, petering along at a rate that took hours and hours to get the bank properly charged.

InteliPower converter charger 60 amp

As an upgrade, I bought myself a high-quality converter charger in the form of the InteliPower PD9260CV. I installed it right beside my batteries and connected it with large one gauge wires. It does a night and day better charge job than the cheap OEM converter located far away in my rigs kitchen. It boils down to 2 – 3 times less generator run time.

I performed a side by side comparison one day when the battery bank was quite run down. The OEM unit was putting out ten amps, while the InteliPower was putting out over thirty!

Wiring, Breakers, and Fuses, Etc.

Using large gauge wires with quality fuses, breakers, and connectors is vital to get maximum performance from your boondocking power system. Wherever I could, I kept the cable runs as short as possible. There are online wire loss calculators that helped me figure out how thick the wire gauge needed to be for a certain distance.

The cables are a combination of (off the shelf) premade and custom built to length by a friend.  I treated all the connection points with Ox-Gard Anti-Oxidant Compound before connecting and Permatex dielectric grease afterward to ensure against corrosion.

Boondocking power system front storage compartment

For circuit protection and convenience I used several waterproof switchable breakers. I have 40 amp breakers on either side of the solar charge controller, an 80 amp breaker to the inverter and a battery disconnect switch to the main RV 12 volt circuits.

They are extremely handy when I need to work on a particular section of my 12-volt power system. Moreover, I can easily shut down the whole system if required. Disconnection may be desirable during a lightning storm or if the RV goes into storage.

Blue Sea Systems 285-Series Surface Mount 40A Circuit Breaker
Price: $36.94
You save: $2.64 (7 %)
73 new from $34.910 used

Because I wired the solar panels in parallel vs. series, I added an inline fuse on the positive wire to each one, just in case one of them shorts out. In that unlikely event, it could be possible for the other four to produce enough amperage to cause an overheating condition and worse case scenario a fire. I added a 10 amp fuse on each panels positive line to prevent this.

More info at this external reference: How to properly fuse a solar PV system by WindyNation.com

As a final failsafe I added in what’s called a “catastrophic fuse” right near the battery banks positive output. This large 250 amp fuse is there just in case some major meltdown happens to the 12 volt DC power system. Hopefully, it blows before the RV burns down!

250 amp cat fuse

RV Boondocking Power System Diagram

Boondocking System Diagram

Boondocking Power System Parts List

Total Parts = $2,766   Note: All parts were purchased by myself except for the Lenun solar panel which I received as a free promo for the review. A few other odds and ends were donated by fellow RVer friends.

Renogy 400 Watt 12 Volt Monocrystalline Solar Starter Kit with Wanderer
Price: $616.57
You save: $63.42 (9 %)
4 new from $609.991 used from $524.00

Off Grid Power System Video Overview

Conclusion

I believe I’ve been able to strike a pretty good balance between and cost, performance, and quality with this boondocking power system. I know of course the payback time of solar versus continuing to use our already “paid for” gas generator will take to take many years. Especially, considering the recent low fuel price.

However, for us, it’s well worth the lifestyle benefits. It’s so nice to be off grid enjoying a beautiful remote landscape while the solar system quietly replenishes our batteries. Or to be able to keep the peace camped amongst tent campers in a National or State Park setting.  Or to spend a few days pavement camping at a casino without worrying about pulling out the generator.

Camped in the Nevada desert

Check out many more dry camping related articles and videos in the Love Your RV Boondocking Archives

Details of our 500 watts 464 AH DIY Boondocking Power and Solar System by the Love Your RV blog - http://www.loveyourrv.com/ #RVing #solar #DIY

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  • Jason Klems

    Ray, good stuff. I just picked up Renogy’s 2×100 watt panel and Adventurer controller for my two Trojan T105 6v batteries (12volt system). I am a rookie to this stuff but I was curious if your travel trailer had some kind of built in converter and how that factors into this. My trailer has a WFCO WF-8955PEC converter. When plugged into shore power it has a feed to help charge the batteries. when this is plugged in, I see my voltage meter jump significantly; so I am worried about overcharging from both the coverters shore power and the solar system. what do you suggest; if you have a diagram that will help me. thanks in advance

    • Hi Jason, You should be fine with the solar on there it can put out the proper voltages and is a smart charger. Rather than overcharging, the biggest problem most RVers face is undercharging causing sulfide build up on the plates and reducing the capacity of the batteries over time. Most people don’t care because they only dry camp for a day or so. But when boondocking for long stretches it’s important to be able to bring the batteries back to 100% charge at least every few days.
      The Trojans can take a high voltage and actually need about 14.8VDC during absorption phase for a good charge.
      The Adventure looks like it puts out 14.6 volts so that’s about right.
      I also have the WFCO as my OEM converter and it is terrible at charging the battery bank so I added a better quality unit specifically for off grid generator charging to help speed it up, less generator run time. – http://www.loveyourrv.com/installing-the-inteli-power-pd9260-for-improved-rv-battery-charging/
      You can see me using it in this video for that purpose – https://www.youtube.com/watch?v=Ppx3gODUPP4
      Cheers Ray

  • Dave’n’Kim

    Great article tying together all your individual stages Ray! Just a couple of notes for other people’s info: we got a big (and also expensive!) Victron Multiplus 3000VA (Watt) pure-sine-wave Inverter, rather overkill for us now, but just because it was suggested as compatible if ever we want to upgrade to Lithium batteries in future, something that continues to hover in the back of my mind. Also, for anyone like us wanting to keep costs as low as possible, I came across a plastic storage bin in Walmart to use to house our 4x 6v golf cart batteries, it was a lot cheaper than the ‘proper one’ you use and a good fit except being 3″ longer (so just add packing to hold batteries in place: I’ll store distilled water there when I find the right size container!) and having to cut out my own cable and vent holes. It has worked well.
    Oh Ray on a separate issue, as someone else asked, would it be possible to have some ‘date stamp’ on your articles so we know when they were written? It can be useful to keep track. Many thanks.

    • Good idea, really frugal. 🙂
      You bet, I remember removing a bunch of stuff that the theme shows to try and keep things uncluttered. I’ll add the date meta back in. Cheers.

  • Slim Lundeen

    I am saving this whole thing as a PDF for future reference; everything is quite clear now but what about next week??? In reading through a couple of comments I wanted to respond to. One is MPPT; you and Bogart aren’t the only two in our RV community that think they aren’t the best thing. Specially when you are traveling and camping in temperate climates and working hard to make sure your outputs match. Wish I had the links but I am sure they are pretty easy to be found. The reason I went with larger inverter I can remember many times Ginie saying she wished we had a microwave. Usually after the steaks have “rested” and she likes her food pipping hot. Stopping to start the genset, heating food, then shutting down and such seems to be a long time when all I want to do is eat my steak. Things to think about when planning your system. And I am not getting Tilly till April.

  • Slim Lundeen

    Thanks for the parts list. I am going to go with the Go Power 3Kw Pure Sine instead because I like lots of head room when it comes to electronics. Totally unrelated but related none the less I assume that if I buy through your links it helps pay for the education that you are providing. After all it’s only fair in my opinion; doesn’t cost any more and keeps these lessons coming. I always price check and don’t usually find it any cheaper. Again Ray, I am Grateful. Slim

    • Yes Slim, the links to Amazon contain an affiliate code so I’m credited with the referral and earn a small commission. Thanks! Ray
      For powering a 3K inverter you’ll want to make sure you have a hefty set of cables between the battery bank and the inverter input. It should say what is recommended in the Go Power manual.

      • Slim Lundeen

        As always length is also a determining factor. I know the Xantrex inverters recommend 3/0 for < 3', 4/0 for 3'-6'. and 500 MCM for 6'10'. IMHO if you have to go any farther you're doing something wrong. And I won't do you wrong; I am a good learner with a good teacher. As always, Grateful.

  • Gladys & Steve

    Hi Ray, I can’t find a date on this post. Is this something that you’ve done recently or was this a starting point that you may have added to.

    I guess what I am asking is if you found this setup sufficient for your needs or will I find that this is an a newer post with more info available.

    • This my system as it stands right now and it’s basically the system I used for many boondocking stints this past spring and worked great for our power needs. The only thing I’ve updated this summer was the addition of the 100 watt Lensun panel for use on the ground. That will come in handy during those mid-winter months with limited daylight hours.

      • Gladys & Steve

        Thanks for your quick reply. Love your posts. They are well written and helpful.

  • Jeremie Hacker

    Hi Ray, love your videos and blog. The batteries are a nice tight fit in the box. Where is the bottom vent hole and is it covered by the bottom of a battery? Thanks, Jeremie.

    • Thanks!
      I used the hole from the original OEM boxes setup. It’s on the box bottom. I drilled out the bottom of the plastic box so the hole is between two batteries so there is some area for air to get in. Seems to be enough, I don’t have any issues with gas build up, but if I want I could add some wood shims under the batteries and raise them up more to get more air through it.

  • Kurt Bischoff

    Ray:

    This is a VERY helpful article. One question — after looking at your schematic, I dont see where the -12vdc for the RV 12v circuits is supplied. The +12vdc which is supplied from the battery selector switch but where are you getting the -12vdc?

    Thanks!

    • The RV’s 12 VDC circuits use the metal RV frame as a negative return line.

      • Kurt Bischoff

        Thanks, Ray! We just bought our first 5th wheel last week so I’m really new to all this. We spent about 10 years sailing a boat across the Pacific and we used solar and wind to charge our batteries but, apparently, RVs are a little different!

        • You’re welcome. 🙂 The frustrating thing about most RVs, especially trailers is they don’t have wiring diagrams. End up having to hunt and peck around for yourself to see how they wired it.

  • Hey Ray,

    This is awesome! I have to admit I’m a little jealous. I want to install solar panels in our RV but we have a few other expenses higher on the priority list right now (hoping to get a gopro soon!)

    My girlfriend and I actually just started fulltiming this month. Any tips for a newbie?

  • Jim Walker

    Hi Ray, I am an electrical engineer and just wanted to say a big thank you. It appears you have very robust and safe design that is working for you great. This blog post was well written and well illustrated. So very helpful! Thank you for taking the time to share with others. What a great example you set!

    • Thanks very much for the kind words Jim. Much appreciated.
      Cheers Ray

  • Kevin

    How do you tilt your panels in the winter to take maximum advantage of the sun that is so low in the winter months?

    • I don’t tilt the roof panels they are fixed in place, though they are on a bit of a slant on the front of the fifth wheel and I always nose into the midday sun when I set up. My goal was to have enough power to not have to climb up and set them up to tilt and have to put them down all the time. We move fairly often. Also, the more times I climb the roof the greater the chance I fall off it. 😉
      I do now have the remote ground panel and can move it around to get the best output, so that should help.

  • chrgrsfan

    Hey Ray, Again I want to thank you and Eddie for the advise on getting my solar hooked up. It seems to be working great so far…This newest write up on your solar is great on how and why you did the things you used.. Hope your future travels are safe..and keep the mod’s and reviews coming..
    LOV’IN MY RV….. Larry

    • You’re welcome, Larry! Will do. 🙂