Solar setup for First-time RV'ers

[andywickstrom]

Hi there,

My wife and I are planning on doing graphic design out of our 2003 16' Scamp trailer and would love any tips anybody might have regarding Solar panels that are affordable and portable.

It would be great to be able to recharge the computer - perhaps one at a time, and possibly run some LED lights inside the trailer, off the solar panels.

Also - for really warm days, is it at all feasible to run the Scamp's "Fantastic Fan" fan or AC purely off solar panels - even if for short bursts? I have seen some of the brief-case style ones, but I'm not at all experienced with these things so I'm not sure how to calculate the amount of energy we would be using versus generating with panels.

We would love it if we didn't have to always be parked at an RV campground, etc, hence the interest in panels. I'm just trying to understand the feasibility of charging some computer batteries, and possibly running a fan on hot days. We would make obvious concessions of power consumption if it meant being able to get work done or run a fan if we get hot.

Thanks in advance!

[deryk]

Hi Andy!

yes you can easily run your fantastic fan, but no you can't run air conditioning off of it.

[andywickstrom]

That's great! Do you have any recommendations on brands or wattages we might consider? The more the better I suppose! I'm open to any and all DIY solutions. I've seen some panels that seem like you roll them out. I wonder if I was able to affix them to a lightweight board and place it out when we find a spot to park? If there was a way to unplug and replug it in each time - that would work for me. Otherwise, the briefcase ones seem pretty handy...

[J Mac]

https://tools.carmanah.com/src.web/G...tm?state=RvDiv

this will give you some idea of what you need for your applications.

[andywickstrom]

Oh wow! That site is pretty awesome. I'm an artist, so I'm gonna have to wrap my head around the amp/volt/watt stuff I think. That guide should be super helpful though. Thanks for sharing!!

[Bob Miller]

You might also be thinking of adding an extra battery so you don't lose any extra charging ability as well as have some reserve for rainy days.

BTW: You will find that many, many campgrounds don't automatically have power hook-ups and those that do are sometimes on the $$$ side.

[Huck]

The most common way of using solar with an rv is to charge your 12v trailer battery(s). Then you use the 12v wiring in the trailer the same as if you charged the battery by plugging into shore power.

So to run the fan, you just run it off the battery as you do now. To charge cell phone, camera, etc (low amp devices), you need a 12v cigarette receptacle like you have in your car. (Or maybe a usb port). In fact, you can charge these devices in your car with the proper adapter.

To charge your laptop, you probably need a small inverter. I just ordered one which plugs into the cigarette receptacle and is rated at 75 watts. So in this case, you are converting dc to ac and then the laptop charger is converting it back into dc.

When you buy a standalone solar setup, you need a solar panel, a charge controller, an inverter, and a battery, plus the appropriate receptacles for plugging in your devices. You can either by each piece separately or you can buy a kit or a briefcase type package.

From reading most of the solar postings here, I think what most do is get a solar panel (60 - 100 watt) and mount it on the roof of the trailer. That is wired to a charge controller that connects to the battery. Then they add 1 or 2 12v receptacles in the trailer. If you need 110v when not plugged into shore power, you can wire an inverter to the battery

[J Mac]

Huck

The brief case style solar panel can be plugged directly into your pigtail using a 7 prong plug.

[andywickstrom]

Hi Huck,

Thanks for all the info - this is great! Do you think it's a concern with mounting to the roof and creating any holes that moisture could get into? I'm just a little bit concerned that I would do damage to the surface, I guess. I would hate to drill a hold that messed it up! On the rooftop solar point, i did see one fellow's setup which was sort of a flexible material that he rolled out and attached to his van with some sort of adhesive I believe. Not sure how much power it generated, but the concept was pretty neat. Low profile and not super invasive on his camper van.

Again, really appreciate these tips. Really looking forward to tinkering on this before we embark on our trip this coming August. Heading west to Colorado from Wisconsin - by way of Chicago. We actually are leaving our jobs and embarking on a new venture doing graphic work and photography out of the Scamp. Once we are ready with everything - our website and whatnot, I'll put it up on the forum. We'll probably blog and I will definitely put photos up. Should be a good experience!

[J Mac]

my solar panel is not screwed to the roof it is glued. You could, however go this route:

Solar panel - Escape Trailer Owners Community

[Bob Miller]

More points:
1. Briefcase type solar panels seem to grow legs when left alone. This means that you can't leave them charging when you are away from the trailer and you will have to bring them in every night. Go with an attached system and study up on how to make watertight mounts. SCAMP has already put dozens of holes in the hull, a few more aren't a big deal.

2. Inexpensive plug-in inverters sometimes aren't all that clean and can induce noise into your computers if you use them while they are charging. I find that my Acer goes crazy anytime I use a plug in inverter, but is OK with my 400 watt Cobra inverter. I would opt for a good 200-400 watt hard wired inverter with it's own outlets. If you are depending on something for a living, you need to go upscale a bit.....

[Huck]

Andy, I haven't mounted my solar panel on the roof yet.

What I did was buy a 100 watt solar panel and a charge controller. I wired the charge controller to a 7 pole plug (like on your tow vehicle). Then when I setup, I simply plug this connector into the trailer connector and connect the solar panel to the charge controller. It takes less than 5 minutes to get my solar set up.

It's not as efficient as connecting the charge controller directly to the battery, but it gave me an easy way to get solar up and running. Plus I have the flexibility of parking in the shade while my solar panel sits in the sun.

[andywickstrom]

Ahh. Good to know. I imagine us working on the computers a bit each day, charging at night or on off days. We also could go into towns and charge at cafés if we really needed it.

Definitely worried about theft, and it would certainly be a concern of mine.

All great tips. I wonder if Scamp would have recommendations on installation on the roof at all?

[Timber Wolf]

I have been researching this for a while, and do not yet have a complete grasp of the ins and outs (volts and amps in and out) of the whole thing but have reached a conclusion. I am going to get a couple of 50 or 60 watt panels and make my own "suitcase" out of them. I do not want to mount anything permanently to the roof (yet) and feel that a single 100 watt panel is too large to store and transport conveniently. I also plan on getting at least a 30 amp controller so I can expand my “array” (panels) without having to upgrade the controller. And, I am strongly leaning toward two 6V batteries just for capacity although two 12V has some advantages also. Like you could rig for 24 volt stuff if you wanted to and if one battery went out you still have 12 volts, etc.

Portable panels allow you to orient for maximum efficiency at each camp. Although theft may also be a concern, just bring them in at night. In order for this to make sense to me I want to integrate solar into my everyday lifestyle and not just when camping. It seems to be too much of an investment to use it a few times a year. To that end I am thinking about what other “loads” I could put on a system when I am home. Fans, LED lighting, my CPAP on an Inverter, even a 12V freezer ($$$$$) are all things I am looking at. Good luck, let us know what you decide!

[Stretcher]

There is 30= page WORD document with loads of info on RV Solar at The RV Battery Charging Puzzle « HandyBob's Blog.
I found much of it helpful in better understanding the whole issue.

[andywickstrom]

Fantastic! I'm reading his site now! Very great link. Thank you!

[deryk]

this is what I bought 12 Volt 100 Watt Solar Panel Kit Solarblvd

Here is me talking about the install http://www.fiberglassrv.com/forums/f...lar-64512.html .

I bolted it to my roof and I'm very confident it won't leak. I lived aboard a sailboat for 10 years that I was renovating so I did rebed all the deck hardware and other then once, when my neighbor, who was a 300+ sized guy lost his footing on his boat next to mine, and grabbed one of my stantion's to catch himself that one I had to rebed it... the butyl tape is awesome!

[mmcwhort]

Originally Posted by andywickstrom

Oh wow! That site is pretty awesome. I'm an artist, so I'm gonna have to wrap my head around the amp/volt/watt stuff I think. That guide should be super helpful though. Thanks for sharing!!

The amps/volts/watts part is pretty easy.

Think of electricity like water. The voltage is the water pressure, and the amperage (also referred to as current) is the volume of water being moved. Your battery is a water pump, operating at a constant pressure of ~12 volts.

Wattage is a combination of volts and amps, and represents the overall power output. Using the water analogy, the wattage would be the flow rate in gallons per minute.



Your devices all use different amounts of power. A phone charger only uses a small trickle of electricity - around 0.5 amps. Incandescent lights use a little more… around 1.5 amps. And the roof fan uses anywhere between 1.5 and 3.5 amps, depending on whether it’s set on low, medium, or high.

The formula for calculating wattage is:

Watts = Volts x Amps

For example, if your fantastic fan were on high, it would be consuming 3.5 amps at 12 volts. The formula would be:

Watts = 3.5 x 12

That works out to 42 watts.

So to answer your original question, as long as you have a panel that's at least 42 watts, you can run the fan all day long without running down the battery.

[deryk]

Well, "So to answer your original question, as long as you have a panel that's at least 42 watts, you can run the fan all day long without running down the battery."

Not totally true... its rare a panel will put out max amps of juice as stated. If you had a solar tracking array that moved with the sun, on a perfectly clear day and the panels are clean with no shadows on them then sure for a few hours.

I'm new to owning solar but have been reading about it for a while. I went with a 100 watt panel because its what would fit most conveniently on my roof. I will eventually add a 2nd smaller panel in the space between my escape hatch and Maxxair vent for another say 50 watts of power.

[Night Sailor]

You need a bigger panel if it faces up and does not tilt, if you want it to charge on a cloudy day, or if you believe in using a nuke to swat a fly.

But if you mostly camp in the summer with long, long days, in good weather, a smaller panel is fine.

The costs for panels seem to be most economic at 100 watts.