Advice on good portable solar panels or mats

Many are happy with a 100 watt (some even less) panel such as the EcoWorthy Portable Panel.

How large a solar charging system needs to be depends on your usage & the amount of dry camping you do. In my case I am a bit overboard in that I have 195 watts (2 panels) on the roof & carry a 160 watt portable panel. During the winter I need all three, however I use 30 - 40 amp hours per day, more than most. With a single battery & no inverter, with normal use of your 12v devices, a single 100 watt panel will probably take care of your needs. My only concern is if you do more than a couple of days of cold weather, cloudy winter camping & run the furnace. You don't want to let the battery voltage go under 12V. A simple plug in volt meter will give you a rough idea of the status of your battery.
 
Considering portable solar, don't know a thing about it. ETI said they would make a port for me for 100.00.

My camping style occasionally puts me out in Colorado between the autumnal and vernal equinox where the sun angle is low and the nights are cold and long. In response I have equipped my trailer with the Escape solar on the roof plus a portable panel for a total of about 300 watts. (The theoretical maximum, which is never actually reached.)

As you can see in the photo my portable is about the same size as the Escape roof panel and is somewhat awkward to lug around. Guessing that combined with the stand it runs about 40 pounds. But in the winter I can aim it directly at the sun and get double, or more, power than the roof panel produces. I also take it along in summer when I know I will be parked in heavy timber (deep shade) and I can move the portable out to a sunny spot. It connects to the Escape provided solar controller through the optional porthole via some 40' of 6ga flexible wire. The panel, stand, wire, connectors and porthole probably totaled around $400.

I don't take it on every trip but am glad to have it on certain occasions. :thumb:

--
Alan
 

Attachments

  • solar0_small.jpg
    solar0_small.jpg
    279.5 KB · Views: 77
I would look at Solar Cells, Solar Panels, Renewable Energy, Wind Energy, Charge Controllers, Solar Trackers - Solarblvd for suitcase panels. It seems like a never ending parade of different sizes, usually getting bigger in watts. The flexible panels still need a framework albeit you can make a lighter one than the aluminum foldable come with. I have just not seen a flexible that is manageable. My 120 watts folds in half and fits in my 21 wardrobe. In mid summer I can easily last two weeks off grid with limited sun due to forest and heavy consumption. I would estimate 15 amp hours per day.

So many variables make it hard to measure. You need to use the proper materials during installation to get the most out of it.
 
My camping style occasionally puts me out in Colorado between the autumnal and vernal equinox where the sun angle is low and the nights are cold and long. In response I have equipped my trailer with the Escape solar on the roof plus a portable panel for a total of about 300 watts. (The theoretical maximum, which is never actually reached.)

As you can see in the photo my portable is about the same size as the Escape roof panel and is somewhat awkward to lug around. Guessing that combined with the stand it runs about 40 pounds. But in the winter I can aim it directly at the sun and get double, or more, power than the roof panel produces. I also take it along in summer when I know I will be parked in heavy timber (deep shade) and I can move the portable out to a sunny spot. It connects to the Escape provided solar controller through the optional porthole via some 40' of 6ga flexible wire. The panel, stand, wire, connectors and porthole probably totaled around $400.

I don't take it on every trip but am glad to have it on certain occasions. :thumb:

--
Alan
Thanks for the info Alan. i am seriously thinking about a portable. Do I need a special port or can I just hook the portable to the battery directly since most portables have a regulator? Which portable did you get and does it come with a sturdy frame. Some of the reviews I have read on some models report the stands are flimsy.
 
Thanks for the info Alan. i am seriously thinking about a portable. Do I need a special port or can I just hook the portable to the battery directly since most portables have a regulator? Which portable did you get and does it come with a sturdy frame. Some of the reviews I have read on some models report the stands are flimsy.

ETI wired in a Zamp port on the exterior for me at build (they suggested it)
Zamp was about $10

my existing portable just plugs right in.

and having a folding suitcase style solar panel that fits into a (stock) 21' wardrobe is a great idea..... as there isnt a big easy to access storage area otherwise on a 21. :)

dont add ETI shelves to wardrobe, of course.
 
ETI wired in a Zamp port on the exterior for me at build (they suggested it)
Zamp was about $10

my existing portable just plugs right in.

and having a folding suitcase style solar panel that fits into a (stock) 21' wardrobe is a great idea..... as there isnt a big easy to access storage area otherwise on a 21. :)

dont add ETI shelves to wardrobe, of course.
Did

Did you have to provide the Zamp port? Do you have to have a Zamp brand solar panel ? How much did they charge to put in your port?
 
Many are happy with a 100 watt (some even less) panel such as the EcoWorthy Portable Panel.

We also had an 80W Eco-Worthy folding panel and I was very happy with the quality of the panel itself. We did not use the provided controller, we bought a Morning Star
SunSaver recommended by Paul. I would have the controller installed inside the trailer close to the batteries and use a quick connect plug (like the Zamp) to attach the panel to the trailer when in use.
 
Last edited:
Been doing solar camping for 20 years and I never advise mounting panels on coach. Much better to use 25' sheathed marine wire and be able to move panels pointing to the sun. I buy my panels (German) (100w) from a guy on ebay ....company is MLI or something. Just do a search on ebay for panels. BEWARE...there are a lot of junk panels out there. Please let me know if you need additional help or step-by-step.
 
Thanks for the info Alan. i am seriously thinking about a portable. Do I need a special port or can I just hook the portable to the battery directly since most portables have a regulator? Which portable did you get and does it come with a sturdy frame. Some of the reviews I have read on some models report the stands are flimsy.

My panel is a simple solar panel without a regulator. If you visit Amazon and search for "150 watt solar panel" you will see half a dozen similar panels. I asked ETI to install a general purpose wire porthole so I connect my solar panel and run various phone and radio wires from inside to outside. The sturdy and beautiful frame you see was designed by myself and welded together by a local welder. ;)

I wired up a connector directly to the existing solar charge controller which at the time was installed under the seat on the passenger side of the trailer. I am hearing that the newer trailers may have moved the solar controller. Fortunately for me my solar controller is just a couple of feet away from the porthole so I used comparatively thin wire for those couple of feet. The main run of wire attached to the panel is 40 feet of 6 gauge. I'll attach a photo of the porthole and the connectors. The 50 amp connectors are overkill for the typical 10 amps you get from a solar panel but are big enough to accept the 6 gauge wire and are big enough for my fat fingers to grip.

A final comment that not everyone will agree on. If for some reason you do not get the solar package offered by ETI you will not have a controller. And if you get a simple panel like mine you will not have a controller. This is really not a big deal if you are willing to check the battery voltage one or twice a day when the sun is shining. Your dual 6V batteries will be difficult to overcharge if you are using a normal amount of battery power. (Normal = lights, fans, radio, etc) In effect you become the controller. On the other hand if you go to bed early and hardly use any power then don't bother charging every day. Again, you are doing the controlling. Just a thought...

--
Alan
 

Attachments

  • shore power cover.jpg
    shore power cover.jpg
    30.3 KB · Views: 23
  • 50 amp powerpole connector.jpg
    50 amp powerpole connector.jpg
    113.4 KB · Views: 26
I hate replying but.........you should never run 150w panel without a charge controller as the consequences are quite disastrous. I don't even run my 20w panels without a controller. I am just trying to help you avoid a very severe problem.
 
I hate replying but.........you should never run 150w panel without a charge controller as the consequences are quite disastrous. I don't even run my 20w panels without a controller. I am just trying to help you avoid a very severe problem.

I will reply - but with a strong disclaimer first. This argument is only theoretical, and in the real world (i.e., camping) running without a controller is not ideal.

But, I will state that it is not disastrous either. First, some specifications of a 150 watt panel - the first one that popped up on an Amazon search.

Specifications
Maximum Power: 150W
Optimum Operating Voltage (Vmp): 17.9V
Optimum Operating Current (Imp): 8.38A

This tells us that under ideal conditions this panel can put out 17.9 volts at 8.38 amps. But the key word here is "ideal". There are two contributors to the "ideal" state for the panel. One, obviously, is full summer sun, at 90 degrees and a cool temperature. The second, and less obviously, is the load that the panel is working into. Using the Ohms law of E=IR (voltage=current times resistance) and solving for resistance, we get R=2.14 ohms (using 17.9 v = 8.38 * R).

Simply stated, if the load that the panel sees is exactly 2.14 ohms, the the panel is working at its maximum output.

Back to the real world. A discharged lead acid battery, say to the 50% point, is a much lower resistance. Attaching a voltage source that can supply 8.38 amps to a "lower resistance" must, by the Ohms law, have a voltage drop that satisfies the equation. (I have seen various figures like 0.05 ohms but take those numbers with a large grain of salt.) What counts is that the large voltage drop can be observed easily.

Using my current controlled battery charger and my trolling motor battery as an example: I can set the output to 20 volts and the amp limit to 10 amps. When hooked up to the discharged battery the voltage drops to around 12 volts - because the charger is not allowed (or "can't") supply more than 10 amps. Over a period of hours the voltage slowly rises as the battery charges, and would, at some point exceed the recommendations for the battery in question. Since I am watching closely I can make adjustments and prevent battery damage This is exactly what we are trying to accomplish with a solar regulator.

If I were the human regulator in the above scenario I would start to reduce the current limit to keep the voltage from exceeding 14.5 (for my AGM type battery).
Naturally I don't want to sit in my garage reading a book and watching the meters on my charger so I set the voltage limit to 14.5 and when the charge has boosted the internal resistance so that it satisfies the E=IR equation ( 14.5=10*R), then the current automatically starts to drop. Usually by the next morning the current has dropped to about 0.1 amp and I define the battery as charged. Since 5 years of trolling has aways been successful, my assumptions must be in the ballpark.

The weakness in the above argument is the magic "lower resistance". In fact a battery is not a resistor but is a chemical reaction rather than a compound that has a specific resistance. But the one thing that can't be ignored is that a discharged battery will pull down the voltage of the solar panel, perhaps as low as the measured battery voltage before charging starts. And the maximum amperage from the panel - 8.38 amps - is well below the upper limit that the battery can accept safely. In fact, the dual 6 volt batteries that Escape uses could probably take 50 amps or more in the bulk phase.

Conclusion: I would be perfectly comfortable hooking up a 150 watt solar panel to a pair of 6 volt trailer batteries and walking away for half a day. This is something you can verify with a panel and battery and a volt meter - which I have done at home, not camping.

But in the real world (camping) I don't in fact know (or much care) if my batteries are at a slight discharge level (90%) or a deep discharge (50%) when the sun comes up. And I want to go fishing the whole day and don't want to come back to the trailer at lunch to check the voltage. So I use and love my controller for giving me the freedom to ignore the whole process. Plus in the winter I use 300 watts of solar which would mean checking batteries about the time the fish start biting. No thanks!

--
Alan
 
This discussion reminds me of the time I came across a situation where 18 volts at essentially unlimited amps, were being used to charge a single 6 volt battery. The whole room was filled with sulfuric acid and hydrogen. A disaster by any definition.

This was a rental boat with four 6 volt batteries, three in series hooked up to one in parallel. The single battery was literally boiling and very hot.

The owner said "Whoops"...

--
Alan
 
Jake I looked at those also. Paul pointed out a concern was potential voltage loss, as the controller would need to be installed between the panel and that plug. The solar controller being installed as close to the batteries as possible means less voltage loss from wire resistance. You would still get charging though, and it has the advantage of using wiring that already exists. As with everything, it all depends on your power needs.
 

Try RV LIFE Pro Free for 7 Days

  • New Ad-Free experience on this RV LIFE Community.
  • Plan the best RV Safe travel with RV LIFE Trip Wizard.
  • Navigate with our RV Safe GPS mobile app.
  • and much more...
Try RV LIFE Pro Today
Back
Top Bottom