The most challenging project to get our RV ready for full-time living was to upgrade the electrical system.
When I purchased the Outdoors RV 28DBS, the electrical system included 1,000 Watts of roof-mounted solar panels, an Onan 3,600 Watt Propane generator, an automatic transfer switch to change AC power from shore power to generator power, a 30 Amp shore power cord, and various AC and DC appliances and circuits.
The Power Distribution Center with circuit breakers (AC) and fuses (DC) is located towards the back of the RV, near the shore power connection. The generator is located at the very front of the rig. The original wiring for the DC circuits comes together at the tongue which is the expected location for the battery.
The rig did not come with any way to change voltage from DC to AC (an inverter) which meant that as designed, the only way to run AC appliances (like the microwave) was to be plugged in to shore power or turn on the generator. In other words, there was no way to run AC appliances using battery power.
I spent many hours researching and designing my electrical system. I decided to use Victron components as they are high-quality and quite reliable.
I was inspired by the DIY electrical system created by Matt Knight of Adventurous Way as well as the professionally-installed version from MYT Solar.
The sketch of my design is listed below:
Phase 1: The Basics
Before I started my main electrical project (installing the inverter), I wanted to take care of a couple of essential items first. The shore power provided at the pedestal of an RV park may not be safe to power your rig, so before you attach to the shore power, you need some type of surge protector and electrical management system (EMS). I chose the 30-Amp model by Progressive Industries. Whenever I pull in to a site, the first thing I do is attach my Surge Protector / EMS. Only after confirming that the power at the site is acceptable do I proceed with the unhitching process.
Most RV parking spots that have electrical hookups have a 15-amp plug, a 30-amp plug, and a 50-amp plug. Since I have a 30-amp rig, the normal connection is to plug my 30-amp cord in to the 30-amp receptacle. There are potential occasions where no 30-amp plug is available, so you need an adaptor (“Dog Bone”) to allow you to connect the 30-amp cord in to the 15-amp receptacle and another adaptor to connect the 30-amp plug in to the 50-amp receptacle. I also purchased a 25 foot extension cord to use when the position of the shore power is too far away from the rear of the RV.
Even though my RV came with an air conditioner and a generator, they don’t necessarily work well together due to the amount of current drawn at the time the air conditioner starts up it’s compressor. The solution is a device called a “Soft Start.” I purchased and installed a “Soft Start” for my air conditioner. This works by slowly ramping up the current to the Air Conditioner instead of doing it all at once. With a “Soft Start” it is possible to run the Air Conditioner using battery power also, assuming you have a robust inverter and sufficient battery storage. It really isn’t practical to run the air conditioner from the batteries for any prolonged period of time, but even an hour or two of air conditioning can make a world of difference on a hot day.
Phase 2: Re-wiring
As noted above, the manufacturer expects that you will install a 12-volt battery (or two) on the tongue of the trailer, right behind the propane. I wanted to install 3 batteries, and they would not fit in that location. The only practical location was to install the batteries in the storage area underneath the bed that Heidi and I use. The space under the bed is quite small, and partially occupied by the wiring for the automatic leveling system. I had to sacrifice 2 drawers and a small cubby (shoe storage?) to make room for the electrical system.
After I made careful measurements, I created a mock-up of the dimensions and then created all of the appropriate cable lengths. I used 4/0 welder’s cable for all of my “serious” connections. 4/0 cable is difficult to work with and you need to make sure that you cut it to exactly the correct size before you attach the lugs.
As you can see, it is quite a tight fit to get all of the components squeezed in to this location:
Once I had the system built in the shop, I disassembled all of it and then reassembled it inside the rig. In the end, I have 690 amp hours of 12 volt DC batteries.
I also had to open up the corrugated plastic underbelly to access the factory wiring. When I opened it up, I found a rat’s nest of wires, all of which were not labeled:
I was able to obtain a wiring diagram from the Outdoors RV factory, but I’d say that the actual wiring was inspired by the wiring diagram as opposed to actually matching the wiring diagram.
Since the original wiring consolidates everything at the load center at the rear of the RV, I had to run multiple new wires from the storage area under the bed to that load center. This required cutting multiple holes in the corrugated plastic, putting the new cables into split-loom for protection, and then carefully running the cables to their new location. Running the 30-Amp AC cables between the bed and the load center was probably the worst part of this entire project.
My RV came with several types of DC outlets: several barrel style (AKA cigarette lighter outlets) as well as several USB outlets. I decided to add a few XT-60 outlets as well. Cigarette lighter outlets are bulky and prone to wiggling out. XT-60 outlets are far more secure.
Once all my wiring was completed, I used a thermal imaging camera to look for any problematic areas. I found a single loose connection (between 2 of the batteries) and fixed that by tightening the bolt at the battery terminal.
Phase 3: Install Monitoring System, and various chargers
Once the inverter was installed, the batteries were installed and the wiring was complete, I wanted to set up a remote monitoring system. I installed a Cerbo GX monitor with a GX Touch 70 monitor. This allows me to monitor and control my system locally (using the GX touch 70) or remotely (using the VRM management console).
Solar panels provide various amounts of voltage and current depending on the current amount of sunlight received, so you need a solar charge controller to regulate the voltage being sent to your batteries. I installed two Victron 100/50 MPPT solar charge controllers.
The final part of the electrical system was to provide a robust DC connection from Red Rover to the RV. As originally wired, there is a tiny wire as part of the 7-way connector that provided enough current from the truck to power the RV brakes, but not nearly enough current to charge the batteries. My truck has dual alternators and can provide plenty of current, but I needed to run a large cable from the truck battery to the bumper of the truck, place a connector there, then run another large cable from the tongue of the trailer to the trailer battery area under the bed, and then install an Orion XS DC-DC charger.
The beautiful part about having 1,000 watts of solar power and the Orion XS, is that I am providing a substantial amount of current to my batteries whenever I drive. When I am driving on a hot day, I typically make a stop 60-90 minutes away from the destination in order to turn on the air conditioner. With the current from the solar panels and the current from the truck (via the Orion XS), I can arrive at my destination with an RV that is a reasonably comfortable temperature.
I learned a lot in the process of designing, ordering, and installing this electrical system. I would not recommend this project for someone who doesn’t feel comfortable working with electricity in confined spaces.