New solar install....

[Jon Vermilye]

I have the GoPower 95 Watt system installed with a pair of 6V Interstate GC2-XHD-UTL (232 AH) batteries in my Escape 17B.

So far I've only had the system get down to 85% running lights (LED), pump, the furnace (during 45° nights set @ 62°), laptop, and cell modem / WiFi Ranger router over 4 days in the shade. In the sun it is back up to 100% by early morning.

[honda03842]

Over 500 miles on the Scotch tape holding the Solar panels down. Though a few other things have shaken loose and require tightening, the panels are solidly attached to the roof.

[honda03842]

Some more info about our solar panels. I have not run our Converter since I installed the solar panels. So far the panels have been able to keep the batteries fully charged.

The other night as a test we left all the trailers lights on for 8 hours. This amounted to a load of 8 LEDs and one incandescent bulbs, a total of 3.6 amps, equivalent to 28 ampere hours on our Group 24 battery. This reduced the battery voltage to about 12.4 volts indicating that the battery had 70% of it's charge remaining.

Of the 3.6 amp test current, the incandescent bulb represented more than half the current. We do intend to replace the incandescent with an appropriate LED when we get the chance.

[honda03842]

We're approaching 1300 miles on the taped to the roof solar panels. They look as good as the day I attached them.

[Ken C]

Appreciate the feedback, You did a great job installing everything.

[DavidSo]

Originally Posted by bdosborn

My guess is the flicker of the lights is from the method of MPPT operation they chose for the controller.

From Wikipedia:

" Constant voltage method Main article: Constant voltage method
This method makes use of the fact that the ratio of maximum power point voltage to the open circuit voltage is often close to a constant value, with 0.76 being a common estimate. One problem with this method arises from the fact that it requires momentarily setting the PV array current to 0 to measure the array's open circuit voltage. The array's operating voltage is then set to (for example) 76% of this measured value. But during the time the array is disconnected, the available energy is wasted. It has also been found that while 76% of the open circuit voltage is often a very good approximation, it does not always coincide with the maximum power point.[5] Thus this method may not give as much efficiency as others, especially if conditions are highly variable or the physical behavior of the cell deviates from expectations. Its main advantage is that it is relatively simple to implement and thus usually less expensive."


Does the watt meter track amp-hrs? It would be interesting to see which controller has a better solar harvest. Boy, I'd sure have to eat some crow if the $25 controller does indeed work reliably in true MPPT mode!


Bruce

Bruce,
I appreciate your input. It may very well be that the lower cost MPPTs are using a different algorythm to control the panels. It may also be that accepting the small loss in efficiency overcomes the cost/benefit problem you described with more advanced MPPTs. "MPPT light", most of the flavor, half the calories

Another point of information: I contacted Solar South, the makers of Norm's panels. Mostly I was asking why the photos of the panels did not match the dimensions listed. Mark Belcher confirmed that the dimensions are correct, not the photo. He went on to say that he could build any size panel I need to a specific dimension or wattage rating. I didn't ask, but I would imagine he can place the output where you want it as well. That is something you never think about till you are routing wires. The lead time is just 2 weeks, and he will quote a price once he has the specs. He said every panel is function tested prior to shipping. His response by email was quick, complete, and friendly. He included additional contact info should I need it. All the manufacturing is in Hong Kong I believe, but Mark is in the US. The email gave me confidence to do business with them.

David

[honda03842]

The email gave me confidence to do business with them.

David[/QUOTE]

David,

I will also say, though we bought standard panels, they came at the speed of light and were ship well protected. As well I had a couple of questions for Mark and he responded quickly.

The tape is still holding the panels down. It's almost like magic.

[honda03842]

I should also mentioned we were parked under an 'acorned' oak tree during a rain storm in GA and heard the acorns pinging on the roof with no damage to the panels.

[DavidSo]

Originally Posted by honda03842

The tape is still holding the panels down. It's almost like magic.

Tape ain't what it used to be, is it Norm? I can remember a time when I wouldn't glue or tape anything that I was serious about, and some part of my brain is still wired that way. Modern adhesives though are simply amazing, and they have quailties that make them better than any other alternative in some circumstances. The heat shield tiles on the shuttle were glued on! Yeah, they did lose one now and then , but 20 years ago they would have left them all on the launch pad . The 3M tape developed for the auto industry is used to hold all kinds of things on like moldings and trim. It has lots of resistance to shock and thermal expansion. It cures over time and actually gets stronger.

I'd like to get one panel, either 100 or 120 watt. That is overkill for my needs now, but I may add an electric frig in the future.

David

[honda03842]

We had an electric fridge on our first trailer. We bought the trailer for the trip to Labrador expecting to have it for only the 2 month trip. The 25 year old Dometic fridge had failed so we bought a dorm room size, 4 cubic foot electric, bigger and nicer than the dometic. Though it did not draw much current it required a 1000 watt inverter for starting currents.

I believe it had a typical duty cycle of 30%. My recollection is that it drew an amp at 120 but about 7 amps to start it.

On hot days we would run it while driving and keep the battery charged from the tow vehicle.

Though it kept things cold, the freezer didn't freeze anything.

[David Tilston]

The Trillium/Outback factory in Calgary does not recommend a propane fridge. They install in their new units a Nova Kool R1900DC. They claim a draw of 2.2 amps. I assume that this would be the average, or continuous load. They are available as DC only, or AC/DC.

Nova Kool, refrigerators, freezers, Marine, RV, Truck

[DavidSo]

Originally Posted by honda03842

The email gave me confidence to do business with them.

David

David,

I will also say, though we bought standard panels, they came at the speed of light and were ship well protected. As well I had a couple of questions for Mark and he responded quickly.

The tape is still holding the panels down. It's almost like magic.[/QUOTE]

Originally Posted by David Tilston

The Trillium/Outback factory in Calgary does not recommend a propane fridge. They install in their new units a Nova Kool R1900DC. They claim a draw of 2.2 amps. I assume that this would be the average, or continuous load. They are available as DC only, or AC/DC.

Nova Kool, refrigerators, freezers, Marine, RV, Truck

Thanks David, that is what I had in mind. They offer a number of retrofit kits that will likely be my choice. I'd prefer a remote mounted compressor.

David

[honda03842]

Solar Panel Temperature Test.
We have two solar panels producing 80 watts. They easily manage to keep our battery charged even on an overcast day, though overcast days have been rare in FL this year.

Typically we are drawing about 20 - 80 watts for 4 hours per night with our 8 LED, one incandescent light and one refigerator muffin fan. I would quess we never draw more than 200 watt hours a night.

Some have wondered if the panels would heat the roof of the RV causing a temperature problem on the roof, maybe effecting the high bond strength tape or possibly heating the interior of the trailer.

I went out at noon to measure the temperature of the panels. They were about 108 F in full sun. There is a fiberglass space between the two 40 watt panels about an inch wide. The temperature of the fiberglass was 98F.

I measured the temperature of the inside ceiling and the temperature was 90 degrees. The outside temperature is about 79F and the inside temperature is 82F. Though the panels increase the inside temperature of the trailer it does not seem too significant.

When a cloud blocks the sunlight the temperature of the panels quickly drop by 10 degrees.

During these tests I was had all the lights and the fan on to insure current draw thru the panels.

Hope this helps someone....

[cpaharley2008]

One quick question, other than possibly removing the RedMaxx where you attached, would you tape the entire edge or just the corners again? Does any water/condensate appear to run under the panels? If you taped the entire edge would you do all 4 or again leave 2 sides open for drain issues. I'm either going to apply direct or attach a small aluminum "L" to raise the panel. Depends on what I can find. That would mean taping the "L" and then taping the panel to the "L". Not sure that is the best way. Maybe I can find a "Z" piece of aluminum?

[honda03842]

I taped all four edges of each panel. I suspect it's not hermetic.

There is a significant dew here every morning. When I measured the temps at noon their was still a lot of water on the roof though none on the panels or within 6 inches of the panels.

Due to the roof's curvature I suspect the only water that might be getting wicked in would be near the corners. I suspect most of the corners have a little tape overlap though I was not doing it consciously.

I have checked the area where the wires go thru the roof after every rainstorm and no water appears to have entered the trailer.

The panels did survive the halloween snow storm, a very wet snow storm with about 3 inches on the roof.

I will check the corners tomorrow and press on the center of the panel. I may see some dew movement if significant air is escaping.

If I were redoing it I would probably be more conscious about the corners. I would still do it the same way from what I can see so far, simply putting tape on the four edges. So far it's one of those rare things that the first time I did something it seems to be great.

I actually see no reason so far to lift the panel off the roof surface.

I'll say one thing that's positive, no one will ever steal them. Not a single person knows they are there, only after I tell them.

[honda03842]

I just went up and pushed on the center of both panels, no apparent emissions. I will say that when you push on the center of the panel it feels like you're pushing on the roof of the trailer. They feel like they are no more than a 1/16th of an inch off the roof in the center.

I will attempt it again in the morning when everythings wet.

Since interior or exterior heating doesn't seem to be an issue I'm not sure why one would elevate the panels. Even if the space filled with water and froze it would only move the panel well less than a 64th. The tape seems flexible enough to handle that.

As to the Red Max Pro 3. It hasn't been an issue though it would have been smart to remove the Red Max and go directly to the fiberglass.

The frontal area of the panel is very low, I'm guessing about 3 square inches. There seems to be no evidence of lifting at all. With the downard slope of the Scamp's roof there also be a downward wind force as well.

The only negative factor with the tape is that getting the panels off would probably be difficult. One of our sons is considering remoting the same panels so he can take them to his next trailer.

I washed the panels for the first time two days ago and after some three months they were just lightly dirty.

[GeorgeR]

I use Plas-t-Cote for permanent external sealing and found it to be foolproof. Bigfoot seals all vents or other attachments (ladder) with this sealant. To end up with clean straight edges I use masking tape on both sides.

Elixir Plas T Cote on Sale - PPL Motor Homes

George.

[Kenny Strong]

Hi y'all

I bought an amorphous "Sunforce" solar panel through Amozon it is 50 watt. I have a 13 ' Bigfoot, with leds through out. Haven't hooked it up yet. It cost $278 plus $35 for the control( they have a less quality one for $19) free shipping. they claim good function in bad weather. it is 2' x3'

[Denece]

Originally Posted by Kenny Strong

Hi y'all

I bought an amorphous "Sunforce" solar panel through Amozon it is 50 watt. I have a 13 ' Bigfoot, with leds through out. Haven't hooked it up yet. It cost $278 plus $35 for the control( they have a less quality one for $19) free shipping. they claim good function in bad weather. it is 2' x3'

We were looking at them last night. Based on our previous experience with solar we were looking at a mono crystalline 50 watter that was only $170. ( and free shipping) We have an NC25 charge controller we'll reuse.
Our little Compact II came to us sans battery or charger so we are pretty much starting from scratch to put in an electrical system in this puppy.
LEDs are a great part of the plan. You also need to consider all your other electrical draws and be aware of where you can conserve when you need to .
We think we have it down so we can go a week on none group24. At least as long as we dont watch too many movies on the ipad! Of course we're ice box types.
50 watts should be a good amount of input. Did you get a 12v panel or something around 18-19v?

Denece

[Larry,C]

Congratulations on your solar panel purchase. Mono-chrystaline was a good choice. One of the most overlooked components in solar systems is the wire. The wire has to be heavy enough for the current to be efficiently conducted. Try to minimize the wire length and use heavy gauge wire. For a 50 watt panel I would use at least 14 gauge and recommend 12 or 10. Enjoy the sun!

Larry Clift
Bluegrass Solar Solutions
larryclift@gmail.com