solar controller mounting for Boler

[Rick G]

Hi,

My son gave me a couple of 40 watt solar panels and a Sunsaver charge controller (he worked for a marine instrument maker and they were throwing these ones out). I am thinking about a permanent installation on top of our 74 Boler (undecided at present). However, I am a bit concerned about running the wires from the panels to the controller in the trailer, because I don't want to make new holes in my trailer roof or sides unless necessary.

I was thinking about runnning wires down the side into an existing vent, but then it occurred to me that the sole purpose of the solar panels is to charge the battery. My battery is mounted in a battery box on the front tongue of the trailer. Wiring runs from the battery into the trailer, as with most trailers.

Since the sole purpose is to charge the battery, why can't I have my charge controller mounted semi-permanently in the same battery box as the battery? The charge controller is physically small enough to fit into the (vented) battery box, to which I might then attach a modest lock to discourage theft (however I doubt that anyone is more likely to steal it than the battery itself, which has not been a problem). The wiring would then run from the solar panels down to the battery box, without having to go inside the trailer at all. The charge controller does not need to be monitored, but I could put a battery meter on the wiring inside the trailer if I wanted to, again without creating more holes in the trailer walls. Wouldn't that work?

I am also thinking about using the 3m high bond tape I have read about on other threads in this forum for attaching the solar panels, but I am concerned that it will lose bond in the -40C degree cold we have here in the winter, as I store the trailer outside under a shelter. Does anyone have an idea about that?

Thanks,
Rick G in Edmonton, Alberta

[Roy in TO]

I was thinking about runnning wires down the side into an existing vent, but then it occurred to me that the sole purpose of the solar panels is to charge the battery. My battery is mounted in a battery box on the front tongue of the trailer. Wiring runs from the battery into the trailer, as with most trailers.

I put my controller under the front bench. Wires run through the floor to the battery. Wires and connectors to the panel run through the same hole.

I've got it set up so I can hang a small panel in the front window for a trickle charge in the summer or I leave a larger panel lying on the bed for winter charge maintenance. While camping I have a stand to set the panels on and direct them to the best sunlight.

Permanently mounting the panels to the roof works but I find I camp under trees and the ability to move the panels around gives me more flexability.

[Steve C.]

Since the sole purpose is to charge the battery, why can't I have my charge controller mounted semi-permanently in the same battery box as the battery? The charge controller is physically small enough to fit into the (vented) battery box, to which I might then attach a modest lock to discourage theft (however I doubt that anyone is more likely to steal it than the battery itself, which has not been a problem).

Thanks,
Rick G in Edmonton, Alberta

I would not recommend installing the controller in your battery box, vented or not. Fumes from the battery would likely corrode and destroy the controller, and there is always the remote possibility that a spark from a relay or other component in the controller could ignite the hydrogen gas produced by the battery causing an explosion and/or fire. The battery box is not a suitable environment for electronic components.

Steve.

[peterh]

Gina D. created a well-thought-out system for connecting her solar panels via a tongue-mounted solar controller box. Might be worth a look.

[Ed Harris]

Most of the decent solar controls I have seen are made inside a potted module just so they can be mounted with a battery.
They also mostly have non-sparking designs for this same reason.

I would think it is a natural location inside a battery box.
I also have not seen a cheap battery box mounted on the tongue that was airtight in any real way.

[Frederick L. Simson]

Most of the decent solar controls I have seen are made inside a potted module just so they can be mounted with a battery.
They also mostly have non-sparking designs for this same reason.

I would think it is a natural location inside a battery box.

My solar charge controller is mounted inside my battery box.
Link

I think you have a good idea, Rick.
My concern would be securing the wires to the shell.

[Al V]

from the installation pdf http://shop.solardirect.com/pdf/solar-elec...ntroller-op.pdf
controller is to be mounted vertically to allow air flow , leave 2 inches above and below keep out of direct sunlight can be mounted outside but protected from rain

[Ed Harris]

So according to the Morningstar site,there are several different models of the Sunsaver.
They are each somewhat different regarding ventilation,mounting,clearance and weathertightness.

Since it took me 20 seconds to find this manufacturers info I would direct you to the site where you can read the exact instructions for the model controller in question.

[Rick G]

Interesting comments. I looked at the .pdf instructrion manual for this controller. I was thinking about mounting the controller on the lid of the battery box, but it appears it requires vertical mounting, so that is out.

However, I don't see any concern for fumes or explosions in the manual, and it is approved for hazardous locations, whatever those are, so it does seem as if I could mount it near the battery in a vertical position, assuming airflow of a couple of inches above and below could be maintained. Since I am currently using a cheap battery box, I will have to think about whether to change it for something that would work better in this application.

Definitely, the next option would be to use the same holes which already exist for wiring from the battery into the trailer, if I put the controller in the trailer. I like Fredrick's idea, but my wife would kill me if I put an access vent in the front of the trailer.

I am aware of the problem with panels on the roof because we also like to park in the shade if possible while camping. However, I think I am willing to live with poor output at times since I don't think we will be stretching the limits of the battery at any time. In addition, roof mounts mean we can charge while driving. As for securing the wires to the trailer, there are several options. I am even toying with the idea of fiberglassing the panels and wires (in a conduit) on to the roof, although this would make the word "permanent" mean more than I usually think of.

Still lots to consider. I appreciate everyone's thoughts and ideas. I will be away from the boards for a few days, but will return in a week or so.

Rick G

[Greg A]

Permanently mounting the panels to the roof works but I find I camp under trees and the ability to move the panels around gives me more flexability.

I don't know parking under trees might be detrimental to your health, and you'll get plenty of sun on the panel out in the open...

[Gina D.]

I am not familiar with the morningstar controllers. Mine are ASCs which are, as Ed mentioned, potted and sealed, so I have no concern about corrosion. The terminals are cleaned every once in awhile as they are exposed, but I packed them in butyl for proction and have had no issues. In my 13 footer, the ASC was mounted sideways inside the battery box. Never had a problem with it.

I have a cheaper no name controller for the rock guard mounted 15 watt panel on my rig. Its just been tucked under the battery handle for a year or more.. had no problems with it either.

[Bruce Thomas]

Who among you thinks the windshield on their automobile can fall out? they can't.....you can use that butyl glue found at nearly any auto paint supply store to affix anything to the roof very solidly...it also has a dampening effect on most things. ......... Bruce



it's available in tubes for use in a caulking gun

[Al V]

Hi Rick
i made a small box out of wood to hold the charge controller on the back it is recessed so to keep most of the rain off of it on the front side i mounted volt and amp meters just to see what is going on. mine is a mobil system i like to keep the casita in the shade and move the panel in to the sun. i used the 3m tape on an aluminum front window guard on my old Trillium the plastic had rotted out and used the tape to hold on a the trill logo that a sign shop made for me to the frame that was in super shape.the 3 m tape held well like super glue . but, i would hate to see your panel go flying off, maybe use tape and a fastener or 2 to be on the super safe side. the windshield you save might not be your own lol just a point to ponder

[Rick G]

Well, I was talking to my engineering student son the other day, the one that gave me the solar stuff. His thought was "why don't you mount the solar panel on the roof of the van, and run the wiring through the 7 pin connector"? I started thinking about that.

My 97 Ford Aerostar minivan has roof racks which would form a good basis point for mounting a solar panel, and I could mount it near the back. I could mount it solidly, with locks to deter (but not eliminate) theft, and could remove it later when the vehicle dies in a year or two (it is approaching 300,000 Km, and my previous Aerostars have been good up to about 350,000 before they rust out). Since these panels were used in marine applications before I got them and have a heavy aluminum frame, I doubt they would break while driving. I am sure the car bounces less than the trailer while driving.

I could run the wires down the back of the van out of the way, into my 7 pin trailer connector at the hitch. I do not have trailer brakes, so I am only using 4 wires of the 7 pin connector at present. On the trailer side, I could run the two additonal wires into the battery box on the front frame of the trailer, where my charge controller will be installed (vertically) within the battery box. I would want to keep the two circuits (solar and vehicle) completely separate, no common ground or anything like that.

This would be a non-standard wiring of the 7 pin connector, however I am not worried about that as I never tow another trailer or have my trailer towed with another vehicle. On the other hand, I can make sure that the pins I use would not trigger the trailer brake lines in another trailer, so there should not be a compatibility problem even if a different vehicle or trailer was involved.

That way, I can charge the battery while driving (when it is almost always in the sun), and can move the van into the sun while camping if I want to keep the trailer in the shade. I would need an extension cord with 7 pin connectors on each end, but only the two wires, to connect up the van and the trailer when they are disconnected from the hitch while camping. Not quite as versatile as a separate panel on the ground, but pretty convenient. I could use a standard outdoor extension cord of maybe 15 - 25 feet for durability and just replace the connectors on each end. With 16 gauge wires and only about 4 - 8 amps of current (depending on one or two panels), a standard extension cord could easily handle the current, and would be durable and flexible.

On reflection, there does not appear to be a downside to this system, except maybe that the solar panel would still be on the vehicle for the 310 days a year when we are not camping. I could think about a mounting frame that can be easily put on the roof racks and locked into place, but removed at the end of the season. I am not averse to drilling holes or making attachments to the main roof rack mounts which are attached to the van, as that would not puncture the roof.

Food for thought, no?
Rick G

[Raya]

I can see the benefits to your idea. A comment and a potential downside:

1) I don't see why you would have to have the panel on your vehicle for the 360 days per year you are not camping - why not make it de-mountable?

2) If you tend to leave your campsite with the vehicle during the sunny part of the day, well, then your panel would not be charging your trailer battery during that time.

Not saying it's a bad idea; just thinking out loud.

Raya

[Rick G]

OK, I finally got the solar system mounted last week and it worked really well. We went out for a short trip last weekend to a provincial park in Alberta, camping without shore power. We used propane for the fridge and furnace, and the 12V battery for electrical needs, including watching part of a movie at night (this was just to test out the new TV/DVD player, we didn't really want to watch a movie at that point).

As described in the previous posts, I mounted the 40 watt solar panel to the roof rack on my minivan, and ran the wiring down to the 7 pin trailer connector on the tow vehicle. I was able to hide the wires inside the rubber door seal on the rear door, for the most part, so you can't really see it there. I snugged the solar panel in between two of the roof rack crossbars at the back of the van, so you can't really see that something is mounted on the roof either at first glance, although it is obvious if you take a good look. I have figured out a way to lock the solar panel in place and still make it de-mountable, by attaching an L shaped bracket to each side of the solar panel that goes across the roof. These go under the roof rack crossbars, then drill a hole through the roof rack crossbar and the L bracket and use a padlock to lock it in place. Because of the lock, the roof rack crossbar cannot be moved to release the solar panel. I will post a picture when I actually get it done, hopefully this weekend.

I connected the +ve output from the solar panel to the battery charge terminal of the 7 pin trailer connector, and the -ve wire to the centre unused terminal. I don't have electric brakes, so the brake terminal on the trailer connector is still left blank.

On the trailer side, I ran wires from the same two terminals up to the battery using the same wiring harness as before, so it looks exactly the same. The charge controller is mounted(vertically) on the side of the battery box, where it just fits in. Having read the manual and knowing that the previous company that owned this thing mounted the controller with a battery in a marine buoy, I am confident that sparks are not a problem.

Also as previously described, I made a 15 foot or so extension cord using an outdoor extension cord and two more 7 pin trailer connectors, but with only the 2 solar panel wires connected up. That way I could plug in the solar panel when the minivan was at the camp site but not actually connected to the trailer.

Anyway, it all worked well. We had a stress free weekend knowing that the battery was constantly being charged, and I even ran the fridge on 12V for a couple of hours to boost the gas performance when the gas was not doing the job (that is the next thing to tackle, it seems that after I took the fridge out this past winter to work on the 12V, that the gas is no longer working well enough). I wasn't worried about running down the battery at night, because it started to charge again in the morning even before we woke up, and without me having to do anything . Awesome! I only had to remember to disconnect the wires before moving the car. This wasn't an issue since we didn't actually go anywhere once we were at the campsite.

I still have another trickle solar panel charger that I can use for maintenance if desired, but this system gives me peace of mind. Also, for those times when we can't use gas, such as on the ferry, I can run the 12V knowing that it will recharge fairly quickly. All in all, a highly satisfactory experience.

Rick G