solar 4 our AS

[lee]

Am going to do solar. my AS has 1 battery which is inadaquate so I plan to have a plat form welded to the current area to hold 2 batteries instead of one.
Plan on using 1 120 watt panel on an a frame setup with a controller then alligator cliped to the batteries for charging.

I am not an electrical genius and have never done solar but it sounds pretty easy, this may be my big mistake,!

The reason I am not mounting on the top is I don't want holes in the top.

Will one of you kind souls tell me if I'm making a great error, yes I realize the AS is prewired for 12 volt for solar, or if I'm on the right track.

Thanks

[davidz71]

While I have seen pictures where individuals have leaned solar panels next to a post in the ground or next to their trailer, have you thought about how you are going to store the panel and security issues or do you plan on disconnecting each time you leave the trailer unattended for just a short period of time?

I use a 5 watt unit to charge and maintain my 2 batteries. The small panel is just placed on top next to my front vent and wires run down to my battery box. I haven't had a problem but I would worry about a 120 watt panel of that size being stolen. Unisolar makes a flexible panel that can be rolled up or just left draped over the top of the trailer and tied down. You still have to worry about someone walking off with it unless your trailer is always occupied or you have a dog on patrol.

[wingfoot321]

Let's keep this thread going. I am also interested in purchasing a unit. I have two new batteries but, I like to rustic camp and haven't bought a generator yet. I really hate the idea of running a generator in some of the beautiful places I have found.

I also like the idea of keeping the batteries charged without the univolt being plugged in all the time.

You might want to look at the units in a farm co-op. They sell them to operate electric fences. I will go back and see what the cost, watts, etc are on these units and post info.

[RoadKingMoe]

If $70 satellite dish setups disappear, what will a $500 panel and $200 controller do? Sprout legs... or wings. Those are pretty good sized glass kites if not tied down well. Look at it this way... how many holes do you already have in the roof for rivets.

On a good day, one flat-mounted Kyocera 120W panel will produce 20-30AH per day, depending on time of year and latitude. A tilted panel will do a little better, particularly in the winter.

Your profile doesn't say anything about your Airstream, but a newer trailer with circuit boards for gas water heater use, gas refrigerator use, and LP detector, as well as a 1A gas solenoid that's on when the refrigerator burner is, and a radio that uses about 1/4A to remember its station settings, can take 25AH per day.

Since you can't park in the shade any more with solar, you may need to run a Fantastic Vent anywhere from low (2A) to high (3A) for maybe 10 hours a day (20-30AH) to get rid of the solar heat that builds up in the trailer. Of course if you camp in the desert there's no shade anyway, so the KC120 will at least take care of daily fan use.

Or when the evenings are cool, it should power a 7.5A furnace running 1/3 duty cycle for 10 hours.

One 2.8A incandescent light for 5 hours is 14AH, 10 minutes of 6A water pump is another 1AH, a couple of hours of a little 50W TV on an inverter brings that up to 25AH (we didn't count the antenna amplifier, or a DVD or VCR).

Looks like you need about 2-3 of those panels depending on how electronic your trailer is. And that's just to cover one day's use, so you'll still need a generator for recovery from one or more rainy days.

[lee]

This is great only 1 day posted message and 3 good replys with with ideas.

I posted my basic idea to find out if I was making mistakes and if so how to improve this system. I take it my basic system , 120 watt panel , solar boost 2003 w/ mppt, connected to batteries, will work but need more panels 2/3 and may neet to be mounted to roof to keep from walking away.

My big concern is the holes I would have to poke in the roof . Anybody out there who has attached solar panels to the roof and has done so successfully , no leaks , please provide your ideas and any other suggestions about improving on my solar idea.

Thanks

[thenewkid64]

To mount the panels on the roof you must do a bit of measuring.

If you can get them to fit, then they can be mounted with a simple L shaped Alumimum bracket. This bracket is mounted to the panel in a location that will sit on a rib. This bracket is then riveted through the bracket and skin to the rib. Use one of the availble vulcem sealers to do it and use large rivets for strength. You will want to "pot" the rivet with a dab of sealant over the top for extra measure.

Before mounting I would wirie the output of the panel to a watertight quick disconnect. This way you are able to install the panels and wire to them afterwords.

One thing to be sure to do is to ground the panel. In the box on the back of the panel where the + and - connections are there is a ground. You may think the mounting system will ground it, but the only way to be sure that there is no static buildup that could kill sensitive electronics (Refer board, furnace boards, on board 12 vdc radios, etc) is to gound this to the panel frame. The frames are not connected electrically with the solar film itself and the movement of air over the panel in transit can cause a big zap.

You mentioned that you trailer was pre wired. Depending on the AWG size of the wire and number of panels, it may be better to re-wire it. You don't want to spend all that $$$ and have the prewire choking the feed to the battery.

[overlander64]

Greetings Lee!

I have a total of three solar panels on my '64 Overlander. The frist two were mounted in 2001 at the Sioux Falls, SD International Rally, and the third was mounted at the Rapid City, SD International Rally. The entire system was installed by AJL Solar (a vendor who seems be at every International Rally). The setup on my trailer includes the following:

2 - 75 Watt Panels
1 - 50 Watt Panel
1 - Charge Controller
1 - Trace Power Inverter and monitor panel
3 - Gel Cell Batteries

The solar panels are permanently mounted to the roof, and AJL Solar used plenty of Vulkem to seal any penetrations. The installation was very neat, and remains leak free and nearly trouble-free. I have yeat to run my battery bank below the 70% charge level - - and that was after a 10-hour travel day with the refrigerator running on 12-volt.

As a side note, it would be advisable to contact your insurance agent after having a permanent installation as some companies require a rider to cover the solar electric system as added electronic components. When I was insured with American Family, I had to obtain a rider for the solar system; when I switched to Foremost, the system was simply mentioned on my regular policy.

Good luck with your solar dilemma!

Kevin

You can see two of the three panels on my coach in the photo below:

[RoadKingMoe]

There are several guys here who've done the mounting themselves and hopefully they'll weigh in.

Be careful with wiring with an MPPT controller. Like an inverter or converter, they aren't 100% efficient. To be of any benefit, there must be sufficient difference between:

1. Panel voltage minus the voltage drop on the wiring between the panel and controller and:

2. Battery voltage plus the voltage drop on the wiring between the controller and the batteries.

It's very critical to keep the voltage drops low, since at high panel temperatures (lower panel voltage) and higher battery charges the MPPTs can be less efficient than a non-MPPT controller. There has to be sufficient voltage difference to overcome their inefficiency.

That means as short of wiring as possible. The factory prewire in my unit runs from the refrigerator compartment, to their chosen controller location under the stove by the furnance, forward to the batteries. By the time I'd add 10' of cable up to the panels, there would be 40' of 10 gauge cable, which would be too much voltage drop for much over 5A of solar current. If I ever did add solar, I'd rewire the trailer with a shorter run of heavier gauge wire, and skip the factory prewire.

There just isn't the battery space or weight capacity in an Airstream to have the kind of battery bank that'll get you through several days of rain with limited solar. Nor is there sufficient roof space to recharge a few days use in a large bank in the same number of days.

A practical solar system will incorporate a generator. While a 1000W will do the job, a 2000W doesn't cost that much more and isn't that much heavier, and will let you run a microwave, hair dryer, or more importantly, a good 120VAC air compressor. It will also be running slower and quieter than the 1000W while providing the same power.

A Honda EU2000, with two 110-120W panels, and a coupla 6V golf cart batteries, or a coupla 12V Group 31 batteries, a 250W Exeltech sine wave inverter, should make a pretty well balanced, if somewhat expensive, electrical system. Don't forget to include a good amp-hour meter such as the Link 10 to monitor battery usage and generator charge.

[74Argosy24MH]

I mounted 2 panels on my mh roof with 2 pieces of aluminum angle sealed and riveted to the roof. This let me span 2 ribs. I used 2 pieces of 1/8x2 flat to mount the panels to the angle. I wanted the panels off the roof for ventilation, they get pretty hot. That also let me keep the wires out of the rain by running them through the roof beneath the panels. No leaks and very solid.

John

[Safari Tim]

Originally posted by 74Argosy24MH
That also let me keep the wires out of the rain by running them through the roof beneath the panels. No leaks and very solid.

How exactly did you get the wires through the roof to where you needed them?

[74Argosy24MH]

To cover the hole through the roof I made a patch about 2 1/2" square. On one side I used a small piece of rod to make an indent large enough for the wires. Covered the plate with sealer, set the wires in and more sealer over them to fill the indent.

Inside took some planning. My inverter is a Prosine and has to be vertical so it ended up under the dinette. The charge controller is mounted on the roof locker. The total length of wire from the panel to the inverter is only about 9 or 10 ft and pretty much all vertical.

John