Making portable solar panels less annoying

[Gina D.]

I have mentioned that I recently upgraded my solar panel system from 3 folding amorphious 13 watters and a rock guard mounted 15 watt unit. I purchased 2 50w multicrystalline panels (At a great price.. 185 each!)

My original intent was to roof mount the new panels, however, I just can not get past the limitations of having shaded panels in a nice site, or really exposed ones in a very hot site. I opted to leave them as portable.

The two panels at 100 watts total are 50% lighter than my other set up, and moving each panel is hardly a strain. They are so light (No sorry, I haven't weighed them) that I can snag them with two fingers and not stress an arm muscle at all. SOOO... they take care of them selves when it comes to the wrestling downside of portables.

Attaching to the battery.. well, that has always been a time consumer for set up and strike. My last system had a nice harness and junction box, but with 4 panels to connect, it still took a few minutes, even without tools.

Here is the "new" system, (Well, the "Master panel, anyway.. I'll explain the two connected later) all set up with a tidy little box of unknown origin that bolts neatly to the trailer frame.

[Gina D.]

First, the "Box". I am not sure what the original use for the box part is.. I saw it all on it's lonesome in an RV parts store near the trailer connectors. It came premade with the braket you see. The large hole in the braket makes me think it is some sort of large connector mounting bracket and the box may be for cables.. or some sort of electronics.. who knows.. but it works for me.

The premounted bolt arrangement reminded me of my hitch mirror set up and a light bulb went off in my head. I could mount connectors and my new 12 amp charge controller in there. So, I did.





I used a car end 7 pin bargman socket on the end, so my "direct" connection to the battery is the trailers own pigtail. The output of the controller is connected to the charge pin of the trailer pigtail connection, and of course, the ground.

The input to the controller is wired to a 5 pin bargman style round pin socket (Only 2 pins used)

The box will not live on the frame permanently, tho that would be nice. For now I will just secure it there with a couple turns of the thumb. The bolt does not seem to bite hard enough for me to be comfortable driving with it attached. I will think of a way to do it, but for now, this still is pretty neat and out of the way and not much bother.

[Gina D.]

The cable from the panel has two 5 pin bargman connectors (One on each end.. doh!) and connects to the output of the "Master" panel which has a socket just like you see on the box input





The socket is mounted in a "Grip Clip", the things you squeeze the handles of your rake, broom etc in, and angled at about 45 degrees for better suport and easier connection. It is held in by friction, and a type of super glue used in electronics for bonding metal to metal (3m "super" adhesive"). The friction grip is very tight, but I wanted a little extra security in case of snags etc, so thus.. the glue.

The "Master" panel has to parallel off to the second panel, so it has an additional pigtail and 5 pin connector to run off to the second panel, which will have a connection as pictured above only. If I get more panels, I can add another pigtail, but I doubt I will be adding.. I have 115 watts total and that seem MORE than enuff for my needs. (Time will tell)

The connector end of the pigtail is stowed in another grip clip for travel. It is not glued :-P. The pigtail as pictured is in it's stowed position.. the wire actually tucks inside the frame and with the clip it stays out of the way on it's own.

[Gina D.]

I went with the tripod stand design. After having owned an array that was on two legs, and some experimenting with stability last week, it is my experience that two legs are a pain. One is always off the ground, the two swing independently and get caught on things, making them hard to move and stow.

One leg in the center provides the needed support and angle, and the full frontal footprint of the panel provides the stability.




I used shutter hinges. I wish this looked a little better, but joe and bubbas weed, feed, hardware and satelite tv store here only had brass ones.. so, I get the rolex look. I gasketed under the mating parts to eliminate alloy mixing, but I don't think it would be and issue in this application.. it's purely mechanical and will probably still be fine long after I leave this earth.

The leg is a 3/4 inch square hollow aluminum tube, length is the full hieght of the panel and the "Foot" end is angled slightly so it will bite into the ground. The leg is stopped by the bottom edge of the panel frame so it will not drop into the back of the panel and potentially break it. It also makes a nice stop bar and longer items can be stow behing or on "Top" of the panels (They ride face down" without contacting the back of the glass.

[Russ & Marian McLean]

Gina,

Looks great, well thought out. Real easy to set up and stow.

I do have a question from the windy edge of the state. We had a small 5th wheel travel trailer blown over in 2007. It totaled our stickie.

Do you have a provision for tying the solar collector to the ground?

Probably need something a little less than my solution.





Russ

[Gina D.]

hmnnn.. yes.. I am thinking that *may* be a bit of overkill :-P

I have not fashion my security system yet.It will consist of a steel flatbar and some locks which will also serve as a way to mechanically couple the panels. This bar will have a place to run my Kryptonite lock thru. I don't think it will keep them from sailing in a galeforce wind, but it will at least keep them in the campsite.

Your solution would work better for theft twarting

[Gina D.]

the Tekonsha stamp on the little box gave me a clue to what it was...

Breakaway switch kit

So, I was close.. the box is supposed to hold a little battery and the break away switch, and it is intended to mount to the frame as I am doing.

It pays to dig thru the junk piles and bargain bins

[peterh]

Bravo Gina! Well thought out, implemented and explained.

[Joe Z]

Gina..... Really Great Job. Much better than my setup. I especially like the way you have the controller inside that breakaway box.............I may have to re-think my setup and thanks for the pictures.
Joe

[Lizbeth]

Well now Eric is going to REALLY want your set up. He has been drooling over the solar panels you bought for days.

[Ian-Vicki]

The box will not live on the frame permanently, tho that would be nice. For now I will just secure it there with a couple turns of the thumb.

Perhaps you could drill a couple of holes in the box, and use a u-bolt to secure the box to the frame without perforating the box steel?
By the way, I'm going to copy all of this.
cheers
ian

[theresa p]

Looks Great

Curious to know where you bought these panels and if they sell the controller/monitor too. We are looking at going to solar for our lot as we have no electric there.

Thanks

Dennis

[Gina D.]

thanks.

I bought the panels from Sun Electric in Florida, but it appears as tho the 50 watt panels are no longer available.

They have 120 watt version for 309! THATS CHEAP!

As the pictures show, the box was specifically designed to hang on the frame, but.. I am not sure what they were thinking with the floating pem nut in there.. it's wobbly. It seem to tighten well enough, but it goes a little kah kah sideways when tightened. I am thinking a backer plate of some sort, or I will find a big old nut to put on the end to make a landing pad.

I am going to keep my rockguard panel, but I bought one of the group 29s from wally world and there is no room in the battery box for my second controller. I bet it will fit in the top of the box.

Liz, Eric is spending all your money!!!

[Bill F.]

Looks Great

Curious to know where you bought these panels and if they sell the controller/monitor too. We are looking at going to solar for our lot as we have no electric their.

Thanks

Dennis

Hi Dennis,
Are you aware of www.renewcanada.com( somewhere in N, no exchange or customs hassle. Their business is off grid so they have some experience. They may not have panels at US prices but I'm going to the post office in the morning to pick up my controller and monitor purchased there. I found a 115Watt monocrystalline Chinese panel locally for C$445.00. Gina's price would be about US$3.70/watt and mine was C$3.87/watt so if you look hard enough you might find something local to avoid shipping and customs charges.
Bill

[David & Leslie]

As usual, a wonderful job of problem-solving complete with tutorial - Thanx, Electro-woman! This will be the way we go if we add more 'oomph' to our solar setup. Hope all's well in the mountains - L 'n D

[theresa p]

Thanks Gina

Looks good we tend to be going to Florida once a year now so we will keep that in mind.

Hi Bill

I did call that company they are about 1hr away was thinking of heading down next week. They are a bit more expensive though as I think he quoted me about 600 for a 100wat panel.

Need to gather all my needs first they see what he might suggest.

Thanks to All

Dennis

[Lisa H.]

I bought the panels from Sun Electric in Florida, but it appears as tho the 50 watt panels are no longer available.

They have 120 watt version for 309! THATS CHEAP!

I'm really interested in these Sun 120 watt panels but am not familiar with this type of panel. The website states that these are: "Made with high efficiency back-contact solar cells." The panel looks like it is polycrystalline. What am I missing? Since I'm not the engineering type, can anyone interpret the data/graph and tell me if these panels appear more efficient than say, amorphous or monocrystalline panels? The price sure is attractive.

Also, how large of a controller would one need to purchase if I got this 120 watt panel? Do I need anything else? I'm trying to get the full picture of the costs involved in adding this to my trailer and cost is a real concern. I already have a battery (probably need two with a panel this powerful!)

Lisa

[Gina D.]

that panel is spec'd at 6.34 Amps so you could get by with a 7 or 8 amp controller..but I wouldn't do the bare minimum.

personally, the cost to go up is minimal and I would go with a 10 or 12 amp one. I have this one asc 12/12 just in case I add more panels later

It is my understanding that "Multi" crystalline and "Poly" crystalline of the same thing. Kinda makes sense in English.

[Lisa H.]

Gina, you must have responded while I was making a simular post elsewhere on the site. I get that etymoligically speaking, "poly" and "multi" have the same root meanings but the problem is that the description of the panels does not say either. In fact, unless I've just overlooked it, the description states that these panels are "made with high efficient back-contact solar cells." What are "back-contact" solar cells?

I will definitely get the controller that handles a larger load. Better safe than sorry. Thanks for the tip.

[Bill F.]

I'm really interested in these Sun 120 watt panels but am not familiar with this type of panel. The website states that these are: "Made with high efficiency back-contact solar cells." The panel looks like it is polycrystalline. What am I missing? Since I'm not the engineering type, can anyone interpret the data/graph and tell me if these panels appear more efficient than say, amorphous or monocrystalline panels? The price sure is attractive.

Also, how large of a controller would one need to purchase if I got this 120 watt panel? Do I need anything else? I'm trying to get the full picture of the costs involved in adding this to my trailer and cost is a real concern. I already have a battery (probably need two with a panel this powerful!)

Lisa

Hi Lisa,
It's a good idea to understand some of this stuff before you start spending money. For example have you done an Amp/hour calculation based on the intended consumption in your trailer? Maybe you don't need a 120 Watt panel. Have you converted to LED lights yet(1/9 consumption compared to incandescent bulbs)? . LED lights are expensive but cheaper than solar panels! If you need the 120 watt panel the next decision is what type of charge controller makes sense. The ASC12/8 [at] $42 is the inexpensive way to go but consider a PWM or MPPT type controller because they have 3 or 4 level charging which most deep cycle batteries prefer, and the MPPT allows using 24 or 36 volt panels which require much lighter(less expensive) wire between the panel and the controller, and the MPPT can harvest 10%-30% more power from a panel than the cheaper controllers will. The MPPT controllers are roughly $250 but if you can use a smaller panel and treat your batteries better(batteries are expensive as well) then it may make sense. Then you may want to have a battery monitor to know how many amp/hours are in your battery at any given time(eg can I run the furnace thru the night?), about $150. You didn't mention what you have for a battery. When you finish your Amp/hour calculation (without this you really can't make intelligent decisions about any of this equipment) you should have a battery that will store at least twice that many Amp/Hours because you shouldn't run a battery below 50% of full charge.

With LED lights(www.superbrightleds.com), a 115Watt monocrystalline panel, a 105A/H group 27 deep cycle battery, a Blue Sky Solar Boost 2512ix charge controller(see the controller and monitor at www.renewcanada.com), a TriMetric 2020 battery monitor, and some wire etc I will have spent nearly $1,300. The ability to stop and camp almost anywhere, priceless.
Bill