Our Electrical/Solar System - A Phased-In Approach

We knew nothing about RV electrical systems when we bought our fifth wheel and and went on the road full-time in 2005.

What we did know was that we didn't want to spend a bunch of money on a battery and solar system until we lived the lifestyle awhile. It took us two years on the road to determine we wanted to upgrade to an electrical system that would allow us to live for about a week at a time (two weeks at most) without electrical hook-ups.

It was never our intent to be serious boondockers, but it takes a pretty good system even to make it a week without having to be really conservative. We have no problem conserving, but the less we have to do, the better. :)

We knew we could easily hang out for a week on our holding tanks and our fresh water capacity, but our pitiful single house battery was just not cutting it. And we certainly didn't want to run our generator all the time.

So we made the decision to phase-in our electrical upgrade. Let's begin the discussion of the details including our costs.

Hint: If you, like us in the beginning, know nothing about RV electrical systems, perhaps it would be best to read through our RV Electrical Systems page before trudging through this page.

In The Beginning

We'll start with our set-up from the beginning and work through our modifications.

We ordered our fifth wheel with the generator option. We were really green. We didn't know why or if we would need it, but we were still employed and we decided it was better to spend the money then rather than later.

We ended up with an Onan Marquis Gold 5500 watt propane generator - $4,900 (early 2005).

That was the only thing we did up front that affected the electrical system in our new RV. And, at the time, we didn't have a clue as to how it fit in with the full-timing lifestyle.

So we started with the generator, the single house battery, and the converter that came with the rig. We didn't know the house battery and converter were inadequate at the time.

The battery was housed in the generator compartment on the far right in the photo above. It was squeezed in below the hydraulic system that runs our slideouts and front landing gear. It was very difficult to access to check water levels and fill the battery.

But, during our first year on the road, we were rarely without electrical hook-ups. We only ran the generator to exercise it as suggested by the manufacturer. We were doing fine with our minimal system.

Toward the end of our first year on the road (May - June 2006), while parked at my parents former farm in the summer, we did a two-week boondocking experiment to see 1) how long we could go on our tanks, and 2) the minimum amount of time we could run our generator and still use the appliances we wanted.

That told us a lot and eased our fears about boondocking a little. That was the point when we learned we could go a week at a time on our waste holding tanks and fresh water tank with just a bit of conservation.

However, that was in the summer when our furnace wasn't necessary and in a place where we could run the generator as much as we wanted. We ran the generator about five hours a day - two in the morning and three in the evening. We didn't realize that wasn't very practical at the time. Sometimes we are slow learners as we ran through two forty pound propane tanks pretty quickly by using the propane generator that much. :)

Our First Addition

Later that summer, we made our first improvement - one we should have made in the very beginning. We added a SurgeGuard Model 34560 50 Amp Hardwired surge guard with voltage protection - $300 (July 2006).

Well, actually a friend of ours added it. For someone experienced, it's a matter of finding the main electrical line, splicing it, and connecting the incoming line to one end, the outgoing to the other, and mounting it in a visible place.

Of course I wouldn't have tried that myself. Camping World and RV dealers can do the installation of hard-wired models. There are also models that can be plugged directly into the campground pedestal and require no installation - a much easier and cheaper alternative (if you don't have a qualified friend).

In our case, we mounted the SurgeGuard in the basement upside down due to the way the main line runs through the rig.

Some of the hardwired models of these devices have monitors that can be placed inside the living area so you can see exactly what is going on with them. Ours doesn't have that and neither do the models that can be plugged directly into the electrical pedestal.

Since that installation, we have been in several campgrounds where the SurgeGuard has shut down our power due to voltage drops or surges that could have damaged our equipment. In our opinion, these devices should be standard equipment in every RV.

Both SurgeGuard and Progressive Industries are both highly recommended manufacturers. If you don't have one, get one!

From that point in the summer of 2006, we went about our happy little way. Again, we had at least an electrical hook-up most of the time even if we didn't have water or sewer hook-ups.

A Turning Point

In November 2006, we attempted to stay in the campground on the beach at the North Padre Island National Seashore on the Gulf Coast outside Corpus Christi, Texas.

Being out and about enjoying ourselves, we were gone from the rig during the posted evening generator hours. With just a little electrical use, our single house battery was dead by morning.

Of course, the battery is necessary to start the generator, so we weren't able to use the Onan to re-charge the battery. We had to plug the rig into the truck and use the truck alternator to charge the battery enough to get the generator started.

Linda didn't want to go through that again, so we had to move from our wonderful beach location to a terrible campground nearby with electrical hook-ups. That's the point when we decided we needed an upgrade. It was ridiculous that we couldn't go one night without a generator.

Getting Started On A Major Upgrade

With advice from people we trusted, we contemplated what that upgrade would look like. But, we certainly weren't going to do an install ourselves.

So, the hard part was finding someone that had the knowledge and expertise to install a sophisticated electrical upgrade. RV dealers are not the place to go.

It takes quite a bit of research to find the few really competent installers. And of course they are rarely where you are. :)

Fortunately, one of the people we knew we could trust was our friend Jack Mayer. He doesn't do installs for just anyone, so we felt privileged that he would take us on. We planned to go to him in the summer of 2007. Through emails and phone conversations, he guided us through options.

I wasn't keen on spending $7,000 for a complete electric and solar system. And I was thinking that a good battery bank and inverter might be enough since we didn't intend to boondock that much. So, with Jack's guidance, we opted to go with a phase-in approach and wait on adding solar panels.

But even though we were going to do a phase-in, we made some expensive choices. We opted for maintenance free Lifeline 6-volt AGM batteries instead of wet-cell batteries at 1/3 to 1/2 the cost.

The batteries were ordered from Battery Warehouse in June 2007 at a price of $1,496 for 4 batteries ($374 each) including shipping.

And we opted for a Xantrex RS3000 inverter/charger over some other less expensive inverters that would have been just fine for our needs.

The inverter came from Solatron Technologies in June 2007 at a cost of $1,460 including shipping. They were out of stock on the System Control Panel for the inverter, so I ordered it from DonRowe.com for $199 including shipping.

Battery & Inverter Choices

So why did we increase our costs by going with the AGM batteries and the 3000 watt inverter? We might skimp on our food budget, get cheap clothes by volunteering, avoid expensive RV parks, and watch our pennies elsewhere. But if we were going to upgrade a system within our home, we wanted to do it the best we could.

Let's start with the batteries.

In my research, I found that most experts agreed that two 6-volt batteries are better than single 12-volt batteries because the combined 6-volt batteries have more amp hour capacity and their longevity is better. The downside is that they are larger than 12-volt batteries and that can be a big issue for RVers when deciding their placement.

Also, my research shows that most experts say AGM batteries are better than the less expensive wet cell batteries. They are maintenance free (no checking and adding of water). They don't have to be vented. They resist shock better - a very good thing in an RV. And they can be placed anywhere, even on their sides. According to my research, the only reason not to buy AGMs is price.

We originally thought we would mount our batteries on their sides in a small compartment and that was a factor in our decision to go with AGMs. Ultimately, we decided to put them in our main basement compartment since we had the room and it would be easier to do all the wiring. However, even had we known that, we most likely still would have gone with the AGMs.

As for the Xantrex RS3000 pure sine wave inverter/charger, it was an easier decision but for a much more complicated reason. Let's see if I can explain.

At the time, every other inverter on the market could not handle 50 amps of power at once. In other words, all other inverters were rated at only 30 amps. That's no big deal if you only have a 30 amp rig, but with a 50 amp rig, additional wiring would be necessary to keep from accidentally frying the inverter.

For anything but the Xantrex RS3000, we would have had to install a sub-panel. That is, we would have to make a new electrical panel and transfer wiring from the main electrical panel (where all the circuit breakers are).

Huh? Yeah, that's what I said.

Basically, to install a sub-panel, you put in a new electrical panel. Then you take some of the wiring out of the main electrical panel and wire it into the sub-panel. You make sure the total of the appliances wired into the sub-panel do not exceed 30 amps and then the sub-panel wiring runs through the inverter.

That way you don't exceed the inverter's capacity. However, you can only run the appliances wired into the sub-panel using your batteries and inverter. The appliances left in the main electrical panel are not wired into the battery/inverter system and, therefore, can only be run on AC power.

With the Xantrex RS3000, we could wire the inverter "inline". In other words, we didn't need a sub-panel and we could wire our main electrical line through the dual 50-amp inputs of the RS3000. It could handle all of our appliances, and we wouldn't have to go through the time and trouble of a sub-panel.

So that's the main reason we selected the Xantrex RS3000 over other good inverters/chargers. Other reasons were that this inverter is a sine wave inverter and that it has an excellent three-stage charger (bulk, absorption, & float) to keep those sensitive batteries charged and charged properly. Many other top inverters had those features, but they could not be wired inline to our 50 amp circuit.

Also, the combination of AGMS and Xantrex RS3000 was great for Phase 1 since we didn't expect to add solar panels for awhile. The AGMs could take more charge faster when using the generator and inverter/charger to charge and the RS3000 gave us maximum charge and re-charging speed.

Electrical Upgrade: Phase 1 (Batteries, Inverter/Charger, and Pre-wiring for Solar)

Okay. Let's get into the details of the intallation of the first phase of our electrical upgrade.

The batteries alone weigh 90 pounds each. We weren't sure that the front compartment where we wanted to put them would sustain their weight, and it would have made the installation tough.

So, we decided to put them in our main basement compartment. We had room and we could favor them to the right side of the rig to offset the weight of the three slideouts on the other side.

You'll refer back to this photo quite a bit as we continue the discussion.

From the above photo, you can see how we placed the four 6-volt batteries - one pair up against the wall and the other pair next to them. Notice the diagonal cables in the middle of each pair of batteries. Those cables go from a negative post (black connection) on one battery to a positive post (red connection) on its mate.

That is "series" wiring. It adds the voltage of one battery to the other battery in effect turning two 6-volt batteries into a 12-volt battery.

On the right side of the battery bank, the negative from the back pair is connected to the negative on the front pair. On the left side, the positive from the front pair is connected to the positive on the back pair.

Think of each pair as one big 12-volt battery due to the series wiring. Those connections on the ends are "parallel" wiring. That doesn't increase voltage, but it increases the total amps available to run appliances.

Huh? Yeah, it took me awhile to get this concept, too.

Well, each of our 6-volt batteries has 300 amp hours of capacity. But that is based on 6-volts. At 12 volts (the DC eletrical system in almost all RVs), each battery has half the capacity or 150 amp hours each.

So we did series wiring of two 6-volt batteries to increase their voltage to 12 volts. Those two batteries then have a total amp hour capacity of 300 amp hours at 12 volts. Adding the additional pair (wired in series) by wiring the two pairs in parallel increases the total amp hour capacity of our four batteries to 600 amp hours.

Got it? Hope so. :)

Now the batteries can be connected to everything else.

See how the positive on the back left is connected to the board on the wall? Well, that positive cable goes through a 400 amp fuse to protect the inverter and battery cables.

That fuse is a National Electric Code (NEC) requirement and the size of the fuse is dictated by the inverter documentation.

The positive cable then goes up to the positive hub (red) in the middle of our mounting board on the wall above the batteries.

Now let's look at the negative side. The negative cable on the front right goes up and connects to a 500 amp shunt.

The shunt is the device that measures everything about the batteries - volts, amps, amp hours used, etc. Without the shunt there is nothing to be sent to the TriMetric monitor we will talk about later. The TriMetric & shunt were $169 from SolarSeller.com - John Drake Services.

From the shunt, the negative cable connects to the negative hub (black) in the middle of the mounting board.

From the positive and negative hubs, positive and negative cables (the twisted cables) go to the inverter. This is where the DC power from the batteries is inverted (changed into AC power).

Oh, there is one other cable going from the negative hub. You can see that it ends behind the twisted pair going to the inverter. That is the ground wire attached to rig frame.

Then, from the inverter, we have two smaller positive and negative wires that run up the wall, across the basement ceiling, and up into our AC main panel. These are the wires conducting the inverted AC electricity up to our AC load center to be passed through to our AC appliances.

In addition, there are smaller wires from the shunt that follow the same path as the AC wires from the inverter. They are connected to the TriMetric monitor on the wall inside the rig.

The TriMetric monitor is what allows us to know how many amp hours we have used and how many actual amps we are using at any particular time (we can test each appliance individually to determine the amps it uses). The TriMetric keeps us from discharging the batteries too far and thus we can extend their lives. It is the one thing we look at constantly to manage our battery usage.

We keep the monitor set on "AH", for amp hours. It gives us a negative number that is the amount of amp hours we are down at any point in time. So if it shows us -50 we have used 50 amp hours of our 600 amp hour capacity. We never want to let that number get below -300 to help the life expectancy of the batteries.

Besides the TriMetric wires, we have more wires that connect the inverter to the System Control Panel for the inverter. The System Control Panel is also mounted inside the RV.

From that monitor, we can see various status readouts, turn the inverter off and on, and turn the charger off and on.

Then, if you look closely, there are two more black wires leading from the positive and negative hubs. Those wires were run across the basement ceiling and up through our bathroom vent pipe to the roof. That was our pre-wiring for future solar panels. That pre-wiring terminated in a combiner box on the roof.

The combiner box was ordered from AM Solar for $63.

The last thing we did in this phase was build a box around the batteries to protect the connections, protect us from electrocuting ourselves, and keep the batteries in place. As you can see, we also added a board to protect all the connections and equipment on the wall.

Oh, one other thing. See that metal box off by itself mounted over the inverter? That is there in case we need to send the inverter in for service or otherwise pull it out. We can use that junction box to connect the main electrical wires currently running through the inverter. That puts us back in pre-inverter working mode.

And that ended phase one of our electrical upgrade. We were pretty sure that it would be a long time before we did phase two and added solar panels. After all, we would not be boondocking very much and when we did, a 600 amp hour battery bank should be plenty and we could re-charge the batteries quickly with our generator if we didn't have shore power for charging.

Total cost of Phase 1: $4,021 including about $650 for wiring, hardware, fuse block, hubs, connectors, etc.

Living With Phase 1

As expected, we didn't park without hook-ups much after we did the Phase 1 installation in July/August 2007.

We did do a little pretend boondocking to test our system when first installed. Then we got a real test when we stayed at Mammoth Cave National Park in Kentucky for a week in October 2007. The campground had no hook-ups and it was cold and rainy.

We were stuck inside and used our computers all day and watched lots of TV. We were running our battery capacity down to about fifty percent (-300 amp hours) by the end of each day.

Each morning we would run our generator to try to charge our batteries back to full capacity. What we soon learned was that the generator would get us to about -100 amp hours before the inverter/charger went into "absorption" mode and slowed down the charge to the batteries. The generator sucks down propane and it was just too expensive to run it to charge the batteries at the slower absorption rate.

Basically, we were getting cheated out of a third of the battery capacity we were willing to use. It quickly became clear why solar panels are a good idea. They could get us back that extra 100 hours of amp hour capacity. Plus they could charge the batteries throughout the day and offset some of our daily use keeping our deficits from getting too high.

Still, we weren't convinced we could justify the expense of solar panels. We wanted to boondock more, but we tried to be realistic about whether on not we actually would.

Since we didn't park without hook-ups again the rest of 2007, and the first part of 2008, we didn't really think about solar anymore. But once we visited Utah for the first time and saw the number of wonderful places available to park without hook-ups, the thought entered our minds again.

For two months we were campground hosts in Arches National Park at a campground where there are no hook-ups. We saw first hand that generators, while allowed and perfectly reasonable, were annoying to the other campers.

In addition, we visited other national parks that were spectacular but also had campgrounds with no hook-ups. And we saw lots of Bureau of Land Management (BLM) land where even we could park our larger rig and boondock.

Suddenly, solar panels seemed like something we really wanted to do even if we couldn't justify their expense. We wanted the option of parking without electrical hook-ups and not having to run the generator, or at least not having to run it any more than absolutely necessary.

We did the research and decided to order panels to complete our system.

Electrical Upgrade: Phase 2 (Solar Panels & Solar Charge Controller)

I've said it a bunch of times and I'll say it again. Solar panels are nothing more than battery chargers. They don't run any appliances directly, they just charge batteries. Okay, they can run some things directly, but in RV applications, they usually don't.

The more batteries you have the more electricity you have available. And the more solar panels you have, the more electricity you can use because you have more ability to re-charge those batteries.

So we should just get lots of batteries and lots of solar panels right? Well, yes. Except that would be very expensive and we are limited by space and weight.

We were most concerned about space and cost. With space and cost factors, we just wanted to get the most panels with the most output that would fit on our roof for the least cost.

I'll admit I didn't do a tremendous amount of research here. My little bit of research showed that panels were not all that different in the big picture. They are rated by watts of output based on standard testing conditions. Note however, that the experts say "real world" conditions are much different than standard testing conditions, therefore we can count on only about 80% of the watt-rating of the panel.

I did compare Kyocera 130 watt panels to AM100 (100 watt) panels from AM Solar.

It was a close call, but the Kyocera panels were actually a little cheaper by watt. However, because AM Solar designs systems specifically for RVs, their panels have a smaller "footprint" and fit on the roof better, and because we've had so many recommendations, we chose to go with AM Solar.

We ordered the Heliotrope HPV-30DR MPPT (Maximum Power Point Tracking) solar controller ($293), the accompanying solar monitor ($158), and four AM100 solar panels ($1,980 or $495 each) from AM Solar. The total cost of the equipment plus mounting brackets & screws, wiring, and shipping was $2,994. Add to that about $50 for additional wiring and connectors and Phase 2 cost $3,044 (April 2008).

Why did we go with four panels?

Basically because Jack told us to go with at least four panels and I wouldn't spend the money on any more than that. :)

The rule of thumb is to match your battery bank amp hour capacity with the total watts of your solar panel array.

In our case, that would mean 600 watts of panels to go with our 600 amp hours of battery capacity as explained above. But I didn't want to spend the money on six 100 watt panels, especially for the relatively small amount of boondocking we would do. We decided to go with four panels and rely somewhat on the boost (discussed below) provided by the Heliotrope controller. If we decide we need two more panels later, we'll get them - we have roof room for a couple more.

The AM100 solar panels produce about 5 amps each per hour. So, with four panels and an average 5 hours per day of optimum sun, our four panels should produce about 100 amp hours per day. However, with the MPPT controller, the panels will supply an extra amp or two each per hour or an extra 20 to 40 amp hours per day.

I'll try to explain. Solar panels generally operate at 17 - 18 volts. AM Solar claims up to 21.5 volts for their panels. But the optimum battery charging voltage is about 14 volts. The MPPT controller somehow converts the higher voltage down to the 14 volts. With our Amps = Watts / Volts equation, the amps produced goes from approximately 5 amps per hour per panel (100 watts / 17 to 21 volts) to about 7 amps per hour per panel (100 watts / 14 volts). So there is a "boost" provided by the technology of the MPPT controller and more amps are pushed into the batteries.

As a reminder, the solar controller is a device placed between the solar panels and the batteries. It's job is to regulate the charge into the batteries from the panels.

In our boondocking back in Kentucky in 2007, in cold, rainy weather, we were using between 150 and 200 amp hours per day. So, with our new panels, we were thinking we might come up a little short in recharging or we would still have to use the generator or we would have to watch our consumption more closely.

Anyway, while at Arches National Park at the end of April 2008, we received the solar equipment and Jack helped us install it.

The Phase 2 Installation

First, we removed the protective panel covering the system. Then we placed the white Heliotrope MPPT controller on the panel wall where we left space during the Phase 1 installation.

Note that we pre-wired from the rooftop combiner box down through the bathroom vent into the basement and across the basement roof to the controller position. We did add a component that we didn't orginally consider.

See the gray metal box to the right of the system panel? We wired the incoming cables from the roof through that. It's a "pull fuse" whereby we can take the controller out of the circuit if we need to for any reason. So the wires come in from the roof and go into the fuse box on the left. Then they go out on the right and they are attached to the positive and negative hubs on the panel.

Wires are then run from the hubs into the controller. Then the wires run back out to the hubs where they charge the batteries.

The white cables on the left coming out of the controller run up and across the basement ceiling and into the rig to the solar monitor.

So here are our three monitors we've added in our electrical upgrade: Inverter System Control Panel, Trimetric Battery Monitor, and the Solar Monitor.

They are located on the wall next to the steps leading to the bedroom.

Once the controller and monitor were in, we set the four solar panels on the roof. We made sure they were spaced just right. We favored them slightly to one side to give a little walkway, and so they would be more toward the driver's side to avoid low hanging branches on the side of the road as much as possible. We also made sure they would not be in the shadows of the vent covers, the air conditioner housing, or the satellite dish.

We ran wires from each panel into the combiner box on the roof that we pre-wired in Phase 1.

I didn't order the optional "tilt bars" to manually tilt the bars toward the lower sun in winter. All the experts say it helps, but many of the people with tilt bars never actually take the time to tilt them. However, we did leave extra wire hidden under each panel just in case we want to add the tilt bars later.

With the wiring done and the panels in place, we secured the panels to the roof with the "rocker foot" mounts and screws provided by AM Solar. We used Dicor over the screws to seal the roof.

So there you have it. Our electrical system upgrade was complete - with the ability to expand in the future if necessary.

The total cost of Phase 1 & Phase 2 combined was $7,061.

That's a lot of money to park without hook-ups on occasion. And we didn't even pay any installation costs. You could probably make less expensive choices on batteries and inverters and maybe go with fewer batteries and solar panels to do your own system for $2,000 to $3,000 less. It all depends on what you want to do with your system.

It will take us at least ten years to recover our investment. It will be shorter for serious boondockers, but an electrical and solar upgrade is a lifestyle choice and it's really hard to justify financially. There is no question you can get more use of it in the wide open spaces of the west where there is more public land, but if you spend most of your time in the east, it becomes even more difficult to recover costs.

Living With Phase 2

Once our system was installed at the end of April 2008, we boondocked in Utah for a week. Out of a week's time, we ran the generator about an hour. On average, our solar panels and conroller were pumping in 100 amp hours per day into our batteries (that's an average including overcast days).

We started each day with about a 100 hour amp deficit, so our solar panels were doing exactly what we had hoped. Our solar panels give us much more flexibility and will certainly prolong the lives of our batteries.

We will continue to update this section as we get more experience over the coming years.


We have had the set-up described above without any change or maintenance since 2005 (batteries/inverter) and 2006 (solar panels, solar controller, etc.) It has been a great addition to our full-timing lifestyle.

During our time in the east, we don't boondock very much. We have an electrical hook-up about 90% of the time. However, when we visit the west, there is a lot of public land, fewer trees, and lots of sunshine.

I still wouldn't consider us serious boondockers, but we spend a good amount of time parking without electrical hook-ups in the west. I'm guessing we spend anywhere from 60 - 90 days a year boondocking or parking in campgrounds without hook-ups ... and we love the freedom and free/cheap camping.

During the summer months when the sun is high in the sky and the days are long, we can go several days without running our generator. Our solar panels re-charge our batteries completely almost every day ... and we're relative power hogs by most boondocker standards.

However, in the winter when the sun is at a very low angle and the days are short, we have to run our generator for about an hour each morning and then sometimes another hour in the evening.

Of course, solar panels are a lot cheaper now and there are certain tax breaks you can get for installing solar on a full-timing RV. And though our solar panels do the job for us just fine, we would certainly have gone with 600 watts of solar panels had the prices been the same back then.

Although I didn't think we would ever recover our upfront costs or our battery upgrade and solar panel installation, we're probably very close to doing that over the time since. We're certainly happy we did it.

At the end of 2013, we just replaced our Lifeline AGM batteries as we were noticing a loss of capacity. By running our generator more and spending time in the east (where we boondock less), we probably could have extended the use of our batteries another couple of years. However, we decided to go ahead and replace them so that we would have full capacity going into 2014.

Update 2

Since the end of 2013, we've been in the east and boondocking very little. However, we did boondock for free in upstate New York for two weeks in 2016, and we've had one and two-night stints several times.

Now, it is the end of 2017 and we are finally heading back west where we boondock a lot more. In fact, in November, we boondocked about 10 days on a lake in Texas and did very well. 

We're still on the same batteries from 2013 and they are holding up well. And we still have all of the same original equipment from 2007/2008. While I'd still like to have a couple more solar panels, it's probably not necessary as we've done just fine with what we have.


As we have enjoyed our electrical system and the freedom that comes with it, we are now holding "Boondocking Rallies" to help educate others in a group setting about parking without hook-ups. If interested, come join us at the next scheduled event.