I thought I would take a few moments and post the completion and initial test of our new Solar Upgrade. I am insatiable about knowledge and the experience of others when it comes to trying something new. There is surprisingly little information on the forums regarding solar upgrades. There are some very bright folks who have taken the time to put together a lot of information for those of us endeavoring to stay away from generators, but very little firsthand experience and photo documentation of upgrades. John Mayer has an excellent write up on the entire process. You can find it at http://www.jackdanmayer.com/rv_electrical_and_solar.htm
. John is very thorough in his write up and though lengthy, contains a terrific primer for getting started.
My wife Jodie and I are new to the world of RVing. We have been tent campers for years, but thought we were ready to evolve. High on our list of "gotta stay away froms" was generators. Some of that bias comes from tent camping in campgrounds that had so much generator noise, we gave up and headed home. Even the whisper quiet ones were "no way" items for us. I don't mean to sound like a purist here, we just know what our preferences are.
Anyway, I set out to convert our travel trailer and last week we took it out for the first time to "give it a go." We knew we would be camping in the trees on the Mogollon Rim in Arizona, so a solar panel mounted on the roof would not work for us. We would need at least one panel to be “portable” enough to be moved around as the sunlight moved. As we had no idea how much power would be needed to keep the batteries at a useful level, we started out with one panel that we could move.
Location of the components was the next item of concern for me. I wanted everything to be relatively compact, easy to access and troubleshoot and as close to the load center as possible. The load center in our Jay Flight is under the oven right next to the dinette. Since we are using a pair of Trojan 31-AGM batteries, I knew out-gassing would not be a problem so I took a hard look at the space under the bench seat next to the oven. It looked perfect to me. I attached a photo of the space with all components set up so you can see how it worked out.
I placed the two batteries as close to the aisle as possible to keep their weight near the centerline. I mounted the Blue Sea battery switch in the front of the bench seat where it is out of the way, yet easily accessible. I then mounted the 1000W PSW Inverter next to the batteries and the solar controller on the wheel well cover. I wired everything together with battery cables from an auto parts store. This was incredibly convenient because two of the cables have small sensing wires coming off the main lug clamp. I used these to wire the temperature sensor and the voltage sense wires from the solar controller. Battery cables come in a wide variety of lengths and with 4 AWG wire costing $2.50 per foot (plus ring connectors), they are a good value to boot.
I installed the fuse between the batteries and the inverter and screwed it to the floor. I also installed the shunt for the remote battery monitor and screwed it to the floor. Next, I used a hole saw to cut a hole through the back of the seat and the end wall of the stove cabinet to route the DC output wires and the AC wires from the inverter to the load center. Out of uncertainty, I completely disconnected the converter because I didn’t know if the solar controller and converter would compete with each other, plus the battery on the trailer tongue is a wet cell I intend to use for the power jack and brake disconnect.
The one mistake I made was disconnecting the common output from the converter distribution board. Apparently, there is a buss somewhere in the trailer wiring that needs the common left connected along with the output of the new batteries. The great news is that I didn’t let the smoke out of anything when I turned the batteries on for the first time… grin!
The next item to be done was running the wires and mounting the remotes on the end of the upper cabinet wall next to the trailer door. With the components located under the bench seat, this turned out to be surprisingly easy. Using a smaller hole saw, I cut a hole in the bottom of the upper cabinet over the dinette. Then through the cabinet end wall into the cabinet behind the microwave, through the other side and easy access to the mounting location. Knowing Jodie won’t tolerate any hack jobs in her trailer, I strain relieved all wires and tie wrapped them together for neatness. I also ran the wires from the bench seat up the wall to the overhead cabinet in a piece of wiremold from Lowes.
Once the remotes were installed in the end wall, I mounted a piece of ¼” birch plywood on the end wall as a false panel to hide the backs of the remote monitors.
Everything worked very well. The only thing left to do was try it in the woods. The MC4 wiring that came with my Carmanah 160 Watt solar kit worked well enough, but there is too much voltage loss in 10 AWG wire, so I knew I would be upgrading that as well. The recommendation is 4 AWG. During our 4 day stay up on “the rim,” the panel charged the batteries just fine. One weird thing was that the remote meter would show a voltage of 13.2 VDC on the batteries, but as soon as I disconnected the panel for the evening, the voltage would drop back to about 12.7 or so. It didn’t worry me because that is a fully charged battery anyway.
We had previously replaced all incandescent lights with led lights, so we could run them all at the same time with no effect on the batteries. We had the Bose wave going, charging on the ipad and laptops at the same time, and never had the batteries drop below 12 VDC. All in all, the system was a huge success.
This week, I wired up a 30’ 4/2 jumper cable and mounted receptacles on the side of the trailer (right outside of the bench seat storage location) (photo’s attached), and the back of the solar panel. Now I can put the panel anywhere with the length of the cable and easily connect / disconnect it for storage.
We have also decided to add another panel and permanently mount it to the roof. That way, we will have the batteries charging while driving or in storage, and can charge with both panels when there is adequate sun. I am running the two panels through another Blue Sea battery switch so I can isolate a panel in the shade, or have them both charging at the same time.
Anyway, this turned out to be a much longer post than I intended, but hopefully it will help and give folks the courage to go ahead and git er done. We saw quite a few Rube Goldberg solar setups in the campground last weekend so it is catching on.
I would be happy to answer any questions if I am able. Again, I am not an engineer, but did manage to install it with minimal difficulty.