Adding Solar Panels

Yes, I'd definately suggest using Stainless Steel, having replaced out almost every exposed screw in my TM's top shell with them myself as the old screws had hardly any threads left on them! (That can be seen on my website as well). And yes, the "brittleness" was one of those VERY hard learned lessons I learned real quick after busting off the heads on quite a few! (I probably sounded like the father from A Christmas Story during the "furnace" scene at the time)! LOL! And that is good to hear about the wood framing not being used at all, I had a feeling about that, I had to use it to fill the gaps due to the difference between the size of the wood that was in there, and the aluminum tubing. But I did treat what wood I used in there as a filler with THREE coats of Thompson's. But all in all, I'd suggest 2.5" stainless steel screws for your application where it goes into the aluminum framework for the best bite possible.

[glow=red,2,300]Happytrails........[/glow]

Ray,
I used a $1.19 tube of Liquid Nails to attach the aluminum feet for my 2 80 watt soalr panels to the roof of my TM. That was back in the spring of 2001 and since then we have spent 2 summers in our trailer and traveled out west and up into Canada and the panels are still firmly attached. It sits outside in the intense Fl. sun all day long so I know the heat doesn't affect the bond.
For my $ Liquid Nails can't be beat.
Good luck with your solar rig.

Bruce

[RockyMtnRay]

Finished the installation this past Sunday and took it out for trial campout on Monday through Wednesday (about a 300 mile roundtrip).

In the end I decided to use just adhesive (Loctite Depend) to hold down 4 mounting pads per panel (5X5 each)...it seemed much easier (and possibly stronger) than trying to use a mix of screws and adhesive. I'm glad to hear Liquid Nails seems to be working for you (which variety BTW, they make a whole bunch of different adhesives) but I was super happy with the Loctite Depend. It's incredibly strong but a snap to apply (activator on surface, glue on the other). About a minute or so to position after placing the panels on the roof, completely cured within a few hours. And totally resistant to heat, chemicals, etc. Probably was overkill...I've theoretically got around 50,000 lbs of tensile strength on each of the 4 pads on each panel...but I wanted to use the strongest adhesive available and I believe I did just that. And compared to the $950 I spent for the panels, charger, wiring, etc., the $32 I spent for the Depend adhesive seeme quite reasonable to me (for piece of mind if nothing else).

Panels are working as expected...I'm getting about the anticipated 11 amps of charging current in full sunshine from roughly 10:30 am to about 3 pm, with at least 5 amps of current from 8:30 am to 10:30 am and 3 pm to about 5 pm. Which is good because the nighttime temps where I was camping this week (Baby Doe CG near Leadville, CO) were in the upper 30s and lower 40s...so the furnace was on for several hours each night and early morning. And even with that amount of furnace usage...and not being at all frugal with the lights...the battery never went below 50% and was fully charged by around 2 pm each day.

The panels are even able to meet the refer's power needs! So no longer any worries about draining the house battery if I choose to make a mid-day stop for a couple of hours while running the refer on DC.

It is sooooooo nice to not have to be particularly concerned about electrical use and battery state while boondock camping....and not having to periodically stay in "RV Parks" (really RV Parking Lots) during trips because I've needed to recharge the battery. In even the nicest ones I find the distance between campsites is so unbearably small that there is really no privacy. (I like the 150 to 300 feet between sites that I typically find in NFS campgrounds here in Colorado).

Pictures to follow...hopefully sometime next week when I pull the trailer out of the garage for some cleaning.

Ray,

Any pictures yet of your installation? My wife and I are seriously considering adding solar to our TrailManor when we get it in the Spring. We have a pop up right now and have been limited to using campgrounds with utilities because of no usable water tank and the need to power breathing equipment at night. (I have sleep apnea and can stop breating at night with the gear.) The gear runs off of 120 or 12 volts. We've been staying mostly at private campgrounds and the sites have been so small. We miss the State Parks we used to stay in.

Well, any way, we are very interested in how it turns out and about how difficult it was to wire in the controller and etc.

Thanks,

Al

[RockyMtnRay]

Should have pictures in a day or three...gotta pull the TM out of the garage real soon now to do some cleaning (and install an electric tongue jack...I am soooooo tired of cranking that handle while standing in the broiling sun down here in the lower elevations).

The wiring actually wasn't that difficult...though a bit time consuming. Since the battery on my 2720SL is in a back compartment, I ran the wire along the top door-side edge of the roof of the front shell, down the the door-side back edge of the shell, down along the rear lifting arm of this shell, thence back under the floor on the door side (going underneath where the torsion bars do). I was able to utilize the screws on the back edge of the shell for cable guides; installing all the other cable guides required drilling (I spaced my guides about a foot apart).

Once I got the cable routed back under the battery area, I was able to utilize an existing hole in the floor where the grounding wire came down to get the cable into the rear compartment. Once there, it was a fairly simple matter to wire the cable from the array to the charge controller (which I mounted on the compartment wall), and then run wires from the controller to the battery. I did get a bit fancy and hooked an analog ammeter between the trailer wiring/solar controller and the battery so that I could get a better sense of how much current was going in/out of the battery under various sun conditions and usage situations.

Working very deliberately and carefully (for instance, I put a dab of silicone on each drill hole before installing the cable guide screw), the whole wiring process took about 6 hours. A fair amount of that time was spent determining the best way to proceed after each stage...."ok, now I have cable under the trailer, what's the best route to get it to the back?", "ok, now I have the cable under the battery area, what's the best way to get into the rear compartment?, "ok, I have the cable into the compartment, where are the best places to mount the controller and ammeter so that I can still get the battery in/out when needed?", etc., etc. Since so much of a TM's structure is very thin aluminum or thin wood, one must be exceedingly carefull in picking mounting points.

And I also periodically stopped and did electrical checks, cable binding and freedom checks (shell up, shell down, shell up, etc.). And since I was doing this on a very sunny day, the panels were kicking out their full output (~16 volts and 11 amps) so I also felt it was better to throw an opaque cover over them while I was cutting and hooking up wires to the various components ('tis not a good idea to be working with live wiring...an "oopsie" can produce a heckuva shower of sparks ). Covered up, the panels produce essentially zero voltage and current.

Hmmm...I think I'll whip up a little diagram of how I did the hookups and include that with my pics. I have Visio and IIRC, it can produce an HTML page. DC electrical just makes sense to me so I can usually proceed with just a mental diagram but not everyone is so enabled.

Ray,

Thanks for the info! I will be looking forward to the pictures and diagrams.

Trust me, I know about the "shower of sparks". That's how I got the nick-name "Sparky" on one job. We were installing a new two-way radio system in an ambulance and it was my job to disconnect the line to the battery switch. I must have grounded out that wrench about 10 times.

Al

Could be worse, lol, I have a friend who earned the nickname, "moonbeam" on his job. He is an electrician, and installs the wiring in moble homes. Lol, he has "unfortunately" fallen through the roof in not one, but two moble homes! Chuckle, definately don't want to earn that nickname with a TM!!!

[glow=red,2,300]Happytrails........[/glow]

[RockyMtnRay]

Ok, I've now got 8 days of camping experience with the panels and it's time for pictures and report of how well the panels have worked (see following post for the report).

First, the pictures (remembered I hadn't taken any pics until just before I put it away after my last trip, so had to shoot with only evening twilight for lighting, hence the subdued colors).

This is an overview shot looking rearward from the very front of my TM (2720SL). The 120 watt panel is in the foreground, the 50 watt panel in the background. As you can see, they take up most of the roof on that side of the trailer.



And this is a shot of the details of the mountings. Attached to each corner of each panel is a "Z-clip", a predrilled, roughly eighth inch thick aluminum offset. The Z-clips attach to the panel frame with a single bolt. I attached the Z-clips to 5 inch plates of 12 guage aluminum (a bit less than an eighth of inch thick) using 2 stainless machine screws & nuts (important note: the bolts you see are NOT going into the TM's roof...only through the mounting plates). The tricky part here was drilling the countersunk holes on the back side of the aluminum plates so that I was leaving enough material for the shoulder of the screws to pull against as the nuts were tightened yet making the holes large enough that the head of the screw was flush with the bottom of the plate (to within about .05 inch). After all the screws/nuts were in and tightened, I did have to do some filing to bring the screw heads flush with the plate bottoms.

The final step was to attach the plates with adhesive to the top of the TM's roof. I used Loctite Depend...an extremely high strength 2-part acrylic adhesive (~1000 lbs/sq inch on painted surfaces) by spreading its resin on the roof (in premarked areas) and spraying its activator on the bottoms of the plates. Once the two surfaces were mated, I had about 3 minutes to do final positioning.

I suspect the weakest link here is the Z-Clip to plate screws, but so far with over 1000 miles of travel in some really windy conditions (air velocity over the roof at least 90 mph) and quite a bit of rain, the mountings are still rock solid. And, by using a straight adhesive mounting technique, I avoided having to drill any holes into the TMs roof.

[RockyMtnRay]

Final report part 2: How they've done.

I've depended on the panels for power in 3 separate campgrounds.

Campground 1 was Baby Doe, near Leadville CO in mid August. My campsite had a north south alignment with fairly tall pines on its east side. I was not getting full sun on the panels until around 10:30 and learned lesson 1: If even a small part of a panel is in shade, the panel's output is reduced by at least 80% (not proportional to the percent of the panel thats shaded). The entire panel must be in full sun to reach it's rated output. To compound matters, the daily mountain thunderstorms built early in the day while I was there so I only had full sun until around 1:00 pm (about 2.5 hours). And being that this campground is at 10,300 altitude, the nights were in the low 30s so I was using around 3 hours of furnace blower each day...and freely using the lights in the evening. Total usage was around 40 to 50 amp hours per day. Nonetheless, the 2.5 hours of full sun and 6 or so hours of shaded/overcast sun were more than enough to fully recharge the TM battery.

Campground 2 was N. Michigan Lakes in remote northern Colorado from Sept 2nd to 5th. Again I had pines along the east side of the camground but started getting full sun by 10 am...and didn't have afternoon clouds until around 4 pm. Again, temps were in the low 30s at night and I freely used the TM's lights. But with more sun, the TM battery was fully charged by the time I got back from my hikes (around 1:30). So I used the extra power to recharge my laptop computer's battery, which it did in about an hour. And I STILL had gobs of unused charging power.

Campground 3 was Timber Creek on the west side of Rocky Mtn NP from Sept 7th through 10th. It is very densely forested with 50 to 70 foot lodgepole pines...so much so that I didn't get completely full sunlight on the panels at any time (the TM was in the largest clearing I could find but the sun angle at mid-day still wasn't high enough to clear the tops of the trees). To compound matters, it was overcast, foggy, and/or rainy for a good amount of all three days that I was there...maybe only 1 or 2 hours of full sunlight each day. Important lesson 2: When camping in late season, it's extra important to have a campsite that is well away from trees (especially on the south and east sides) because of the much lower sun angle.

Because of the relative paucity of full sunshine, I substantially cut my use of the TM's lights and didn't let the furnace run quite as often (thankfully the temps were in the high 30s at night). The net was I using around 40% of the battery's capacity each night and the panels were giving me around a 30% of capacity recharge. By the morning of departure, the battery was down to around 35 percent charge level...still enough to show 3 lights (including the "G" light) on the TM's battery monitor but only about 12.2 to 12.3 volts on my voltmeter.

The trip home (about 5 hours) was almost completely in full sunshine. And even though I had the TM's refer running on DC, the combination of DC current from my TV and from the panels was enough to bring the battery fully back up to 100% power by the time I got home.

Conclusions:

(1) Don't just plan your array to barely replenish each days use and assume you'll have a full day of sunshine to do this. If I have a full day of sunshine, my array will produce at least twice my average usage, probably 3 times my frugal useage. Plan instead to be able to get a full recharge in only 3 or so hours of sun; or in a full day of cloudy conditions.

(2) Plan/pick campsites and campgrounds that provide sun during the times of the day that are most likely to be sunny. "Shady" is not a good word for camping with solar panels.

(3) With only the standard TM battery, 4 to 5 days of continuously cloudy weather is about the limit even with panels if the furnace must be periodically used to stay comfortable.

I am seriously considering a solar kit for the TM. This Christmas we will be dry camping in Big Bend Natl Park for a couple of weeks and I know it will be cold at night. I have mentioned the Heater Buddy and the Olympian heater but think that I need to consider electrical needs too.

What is the possibility of using a non-mounted panel, one which you can move around to capture the sun?

Camping World sells a "plug and play" system. Any feedback on their system?

I am not electrical :'( and need to have someone do the wiring etc and want to keep it simple enough that no one can screw up my TM. Any advice for a "no" do-it-yourselfer would be appreciated.