GnuAttitude

Nothing can cause problems with a charging system more than corrosion. It is something that needs periodic maintenance wherever you typically find a battery, such as in your car. Even if you have a maintenance free battery, you still need to clean the terminals every once in while or eventually you will lose contact with the battery. In an RV environment this will usually lead to undercharged batteries or no charging at all. Not things you want to become issues when you are in the boonies.

This is even more problematic with the way that the wiring is done on the North Trail.

What you are looking at in the picture is what I will refer to as a junction block. It consists of two 30 amp fuses connected with a copper bar. The left side in the picture is the positive battery cable, the right side the 12 volt feed to the converter and fuse panel inside the trailer. The smaller red wires are providing power to the braking system and brake lights and turn signals. The problem here is that this is mounted exposed on the front of the trailer. It does have the rubber boots that kind of cover it but as you tell from the amount of rust on it, it gets fairly wet if you are driving in the rain. Eventually this was going to cause a major headache, so as part of my upgrade to the solar charging, I decided I needed to do something about this.

I think the reason that the fuses are exposed like this is because the underbelly of the North Trail is enclosed. If the manufacturer had placed this behind the frame it would be covered and you would have to take down the plastic underbelly material to gain access. I would think an enclosure or box to house this arrangement would have been better but some things in the RV world are shall we say, a little deficient. This mod cost me about $20.00 so it wouldn’t have been too much of a burden while the trailer was being built.

This what my “junction box” ended up looking like. The plastic box is just a plain waterproof enclosure purchased from Home Depot. The conectors on the sides I had to drill holes for and they tighten around the wires to create not quite a waterproof seal but pretty close. I re-used the 30 amp fuses after I cleaned them up. This is what it looks like with the cover on.

The biggest obstacle with this mod was that the wires on the trailer side of this block were VERY SHORT. I had a hard time to get them into the box but there was nothing I could do as they go back through the frame so changing them wasn’t an option. While I don’t expect to have this remain corrosion free forever, it should stay dry and holdup alot longer than what was there.

The second spin off from the solar panel install was a new battery box.

When I picked up the T-105′s I was disappointed with the selection of boxes to hold 6 volt batteries. Part of this stems from the fact that the batteries are connected in series in a typical RV application, so they need to be connected to each other. This requires they are close together so most of the boxes on the market are built to hold 2 batteries side by side. These boxes were, well, boxes. They were “functional” but pretty ugly and they were going to require some modification of the rails hold my existing batteries in order to make them work. I also knew that I might eventually need 4 batteries for my system. I thought about getting a truck storage box but I was going to have to hack it up to make it work for batteries. These also aren’t cheap. I thought if I was going to have to spend a couple of hundred bucks for a box, I could build one for that price, and I could make it EXACTLY how I wanted.

And so the custom battery box was born…..

I am actually pretty lucky that I have as much room as I do on the frame of the North Trail. Some trailers just don’t have room for batteries, let alone 4 of them. I don’t think much thought goes into that at the design meetings, because most people want hookups when they camp. Battery placement is not high on the priority list. Perhaps it was inadvertent, but the design guys at Heartland left plenty of room on the front of the North Trail.

Originally the 12 volt battery my trailer came with was mounted in channel created by 2 pieces of angle iron. The T-105 is pretty much the same footprint as a 12 volt, except it is a bit taller. Because I was planning to have 4 batteries I turned them sideways so they would all fit within the width of the frame. I did remove the angle iron channel, and the metal supports that make up the spare tire storage served as the mounting points for the new box.

Above is a shot of the project mid construction during a dry fit. I built the box entirely out of 16 gauge (1/16″ thick) metal. I had the individual pieces cut at a shop I use and then had it welded together. The latches are your basic tool box latch that can be locked. I tacked these on instead of using bolts. For the vents I got a plastic vent (white in the picture)  at a local RV parts store. It is a vent typically used in RV’s where the battery box is vented by hose to the outside. I placed a vent on either side of the box and it gets good cross air flow.

Since I only have 2 of the 4 batteries right now, I placed a couple of dividers in the box to keep the 2 batteries centered and prevent them from tipping. Having them side by side also allows for easy connection of the wire that connects from the positive side of one battery to the negative of the other. Wiring the batteries in this way produces the required 12 volts from the 2 – 6 volt batteries.

I replaced both the negative and positive battery cables as part of this project. The ones on the trailer were too short and they were already pretty damaged from the sun. Because my box is a trapezoid shape, I have 2 triangle areas on either side that will be empty even when I have 4 batteries installed. I used this area as the place for my cables to enter the box. I used a plastic strain relief connector like I used on the junction box that will keep water out and prevent the cable from getting cut on the metal. For paint I did it myself with standard metal primer and black paint.

This what the finished install looks like. I don’t think it looks out of place on the trailer, but yet this is totally custom. Overall I spent about $140.00, and $80.00 of that was having the lid cut and bent. I could not have bought anything for this amount that would have held 4 batteries and fit the trailer as well as this does. It also doesn’t add much weight, which is important when each battery weighs 62 lbs.

This was my first BIG mod. It then spawned two smaller ones. But that’s what happens right, once you get going you can’t stop…

One of the really great things about camping is getting away from the crowds of people in the city. Sometimes what happens though is you get to the campground and you are packed in worse than in the city. Not exactly my idea of relaxation . The solution of course is dry camping, without hookups. The lack of hookups usually means less people. However, dry camping or boon docking as some refer to it, comes with some challenges, depending on how much you want to “rough it”.

First a few words about solar panels. They are NOT a power source like you get when you plug into a 120 volt outlet. They won’t run your A/C or any other 120 volt appliance that you may carry. If you need to run those while you camp you need a generator or a site that has power. What a solar panel does do is provide charging to your batteries which in turn power all of the 12 volt items in your trailer. Actually, a typical trailer can provide many comforts of home all by itself with it’s own 12 volt system. Your lights, refrigerator, furnace, stove and water pump all use your 12 volt system in some way, some in conjunction with propane gas. The point here is that your trailer is essentially self sufficient to provide your basic comforts. What can limit your dry camping experience though, is how long your batteries last. That is where the solar charging comes in.

Solar and RVing are made for each other. The basic premise of going out in an RV should be to get away from our everyday distractions. You know what I am talking about, the TV, the video games, the cell phone, etc. If you want to watch TV why go out in your RV to do it, you could stay home and watch. Time in your RV should be time you spend with your family. These distractions usually require 120 volt power as well so they aren’t the kind of things that mix well with dry camping. What we do want to be able to do when RVing, is have our lights work at night so we can get ready for bed, or perhaps read a book if it is raining outside. We want to be able to have our furnace run to keep the trailer warm. We want the water pump to supply water for washing. Power for all this is coming from your batteries when dry camping.

Batteries can be a complex subject, and this site lays it out better than I can. We chose to go with 2 Trojan T-105 6 volt batteries. No matter what kind of battery you have, it has a limit to how much power it can supply. Depending on how you use your RV, your batteries won’t last much more than 2 to 7 days without being recharged. This is where the solar is the perfect compliment. The solar panel produces electricity from the sunlight which through a charge controller provides charging to your batteries. This charging takes place as long there is sunlight hitting the panel, and varies through the day depending on position of the sun, cloud cover, etc. The more light, the better the charge, and depending on how much power you need every day and the size of the solar array, you can extend your dry camping to several days without a charge or even dry camp indefinitely. Or until you run out of water, that’s another matter…….

When I started to research this project, I knew little to nothing about solar power. I now know enough to be dangerous and the information I provide here is how I chose to do it for my North Trail and my skill level. It may not fit your situation and/or skill level so be warned, this is only a recap of what I did. If you don’t feel comfortable doing a project of this scope it is always best to seek out a professional to do your install.

The first thing you should do when considering solar is figure what you  will need from it. A system can be as simple as a single panel and controller to more elaborate systems consisting of several panels, charge controllers, transfer switches and inverters. The panel and controller I have came as part of a kit from Carmanah. They have a useful calculator on their site that can help you decide the kind of system that will fit your needs. I designed my system knowing that in future I will want an inverter to power a hair dryer (hey she can’t live without it!).  When finished it will consist of 2 – 110 watt panels, charge controller, and 1750 -2000 watt inverter. Because of the cost, I was forced to do this over what will amount to a couple of camping seasons. What I describe here is the install of one panel and the charge controller.

I may as well start from the top down. This panel is fairly large, roughly 2′ x 5′, so you may be limited as where to place it on the RV roof. I looked for a location that was close to the vent for the fridge as that was where the wires were going to enter the trailer. I also positioned it knowing that I wanted to add another panel down the road, and I still have room to place them side by side. You should try to position the panel so that it is clear of vents and your AC unit so that you don’t get shadows. In my opinion this is tough to do depending on the layout of your roof. My practical experience after having this for one summer proved to me that I had shade and shadows from overhanging trees which affected it more often so I am glad I chose ease of install over trying to really maximize the best possible location.

I mounted the panel length ways across the trailer using the hardware that came with the panel. It came with something called a well-nut, which I was skeptical could hold this panel in place going 100 km/h down the highway. It is in hindsight a pretty strong bond to the roof, and I covered the entire mounting bracket in self-leveling sealant to make sure that no water could leak in. On the back of the panel is a junction box that has a couple of wires, one positive and one negative coming out of it. Fortunately, this kit is friendly for the do it yourself people as they are already wired into the junction box and have an end ready to plug into the wires that will run to the charge controller. I liked this feature and down the road when I add the next panel, there is an adapter that connects to allow 2 panels to plug into the wires running to the controller.

You are limited to the distance that you can place your controller in relation to the panels, and that distance is 25′. Figuring out where to put the panel was actually the easiest part of the install. Deciding a good location for charge controller within 25′ was a different matter. The logical choice was in the wall that was adjacent to the refrigerator because that was the shortest distance given the wires were coming down the refrigerator vent. The problem there was although I had good access to the vent cavity behind the fridge, I didn’t want to cut a hole in the thin luan board wall. Compounding that was if I ever wanted to remove the system and put it in another trailer, I would have a hole left in the wall that I would have to cover up. Although it was a good spot because it would be very visible at eye level, I decided that I didn’t want to look at the controller all the time or a hole if I took it out at a later date. I decided that I would install the controller in the underside of the dinette seat closest to the fridge. In hindsight this worked out well as my furnace was located under the refrigerator so gaining access to the dinette with the wires was very easy and did not require drilling holes through walls.

As you can see there was ample room directly under the refrigerator where the furnace sits. As the dinette was right next to it I only had to run the wires through the same opening the duct work goes through. One suggestion for the wire that comes with this kit. It is basically one long wire that needs to be cut in half or basically two pieces to make a positive and negative wire. Since the wire is black and has no distinguishing marks it is a good idea to mark the positive and negative so you don’t get them mixed up. Connecting to the wrong terminal can damage your charge controller and/or panel so be very careful. There are no connections to be made at this point but it is almost impossible with normal tools to tell which wire is which after you have fished them through several openings.

Here you can see the wiring added under the dinette. I enclosed both in flexible plastic tubing to give it a finished look and attached it with hangers to the wood. The right side is the wires coming from the panel. The wires on the left I had to purchase as the kit did not enough to reach my batteries from here. This is where I think it prudent to mention another important point.

When I began my research I talked to people who sold these systems and asked a lot of questions. As I had no clue what was involved one of my questions was how do you get the power from the panels to the battery. Oh this is easy one guy says, you come through the fridge vent (which I did) and then you just connect from the controller to the 12 volt wires that connect to the back of the refrigerator. The idea being the power will flow back through to the battery. THIS IS NOT THE CORRECT WAY! and don’t let anyone tell you different. The main reason is these wires are not sized properly for the kind of amp loads coming off the system. You could cause all kinds of problems not the least of which could be a fire. Who wants there trip ruined because you took a shortcut. Secondly you are back feeding power all the way through the converter to make it to the battery, how can that be good?

The right way is to run wires directly from the battery side of the controller to your battery, with no interruptions. The most important thing here is that you have the proper wire size. In deciding this you need to know the amp load, which in this case I have a max output of 6.7 amps per panel, with the controller being capable of handling 25 amps. As I want to expand I went with 25 amps as the max load. #10 wire is good for 30 amps and my distance from the controller to the battery is about 25′ so that is what I chose. I was able to pick it up at the local hardware store and it was relatively cheap. I went with stranded as it is more flexible.

Once I had the wire I had to get it to the front of the trailer where my batteries are. As my North Trail has a nice enclosed underbelly I thought it best to get the wires under the floor and then run along the inside of the frame to the front. The first obstacle was that under the dinette containing the charge controller is where the water tank is located. Can’t drill a hole there. Lucky for me the furnace ducting ran in an enclosed box along the wall and was exposed for a few feet in the opposite side of the dinette. On that side I drilled 2 holes through and fished the wires into the underbelly. From there it was a straight line to the battery.

It is recommended that you keep the panel covered until you have all you connections made. I connected the panel to the controller first. Then I connected the wires running from the battery. Once it is hooked up you should have a voltage reading. This is the actual voltage of your battery. A good thing to test here using a hand held volt meter is you should have the same voltage reading at your battery terminal that you have at the controller connection. This will tell you if you have any voltage loss over the wires connecting to your battery. You don’t want any voltage loss here and if you do you will need a larger wire.

Once the connections are made then you can uncover the panel. You should have two alternating readings on your controller. One will be the battery voltage as shown in the picture. The second will be the charge amps that are being delivered to your battery.

The peak output for the 110 watt panel I installed is 6.7 amps. This would be under ideal conditions with the sun directly over the panel. Real world this is isn’t going to happen. The highest I saw during this past season was 5.4 amps, which to me seemed pretty good. I expect an average of 30 amp hours of charge back to my battery bank each day. My usage varies each day, especially if it is cold and we run the furnace for extended periods. I was very happy with the overall performance of the system. There were times when the charging was minimal, and we relied on the battery alone to keep us going. However, if the sun was shining even for only part of the day, we usually had a full battery when we went to bed at night.

Solar works for us, but it isn’t the cheapest route. So far for my single panel and 2 batteries I have $1400.00 invested. When I add the second panel, inverter and a couple more batteries the total cost will be around $4000.00. Now you can go out and buy a good quality Honda 3000 watt generator for about $2200.00 that will provide power to operate everything in your unit, including the A/C. What I don’t like about the generator is it always needs to be feed gasoline. They make noise when they run, and even if it is a good one like the Honda and is quiet, you still have to listen to it. Depending on where you go, some places won’t allow generators. There is also the theft factor. If you leave your site for the day you need to lock down your generator, especially when boon docking. When we pull in with the solar, we are already setup. Everything is permanently mounted and requires no setup. It is environmentally friendly and makes no noise. Of all the the benefits I appreciate the silence the most.

The install took me about 14 hours. I typically work slow and I really tried to do a good job. The nice thing is that adding another panel is just a matter of mounting it and hooking it to the existing wires. All the hard work is done and is sized with expansion in mind.

I learned a lot with this project. Hopefully my experience helps you with your solar project! I’d love to hear about it!