The "How much solar do you have on your Micro Minnie?" - Page 2

tinglett · 10-02-2022, 08:31 AM

I have three Renogy 100W panels I recently installed on struts. The struts are spaced from the roof with 1/8" aluminum spacers I made that are wrapped with double-stick eternabond tape. I screwed them down into the rafters since I didn't feel I could trust the TPO roof to hold together in the wind. I spaced the struts from the roof so water could escape instead of being channeled into the vent/sunroof in the back or the A/C in the front. Note the panels are shifted street-side so I have a path to walk on the roof.

I haven't run a cable to the batteries yet. Right now I go on the roof and toss a cable down to plug into the side where I repurposed the "zamp" solar connector to feed into my Victron 100/30 charge controller. A permanent cable is a project for another day.

splitley · 10-03-2022, 10:39 AM

2x100on roof and a 26 watt on side, with 2 separate controllers on a 2018 2106DS

No1Hunter · 10-03-2022, 11:25 AM

tinglett, are your "struts" aluminum and where did you get them?

tinglett · 10-03-2022, 05:55 PM

Quote:

Originally Posted by No1Hunter

tinglett, are your "struts" aluminum and where did you get them?

In the end I went with standard electricians galvanized strut channel you can find at any home center. However, originally I bought some 8020 T-channel (https://8020.net/1575.html) which you can buy to the inch (don't go via amazon). The T-channel is very beefy, and so just as heavy as the electricians strut, and in the end I decided that I preferred the open slots in the electricians strut for drainage.

I originally was going to eternabond the T-channel down, but then had the realization that it would guide water into openings, and it also would depend entirely on the TPO holding down. So I changed plans and saved the T-channel for some other project I'm sure will surface someday

I'm very happy with the result. I doubt the double-stick eternabond is ever going to leak as the screw sucked a fair bit of it into the hole. But I still slathered it with sealant as that seems to be "the RV way".

I made the brackets and spacers from 1/8" aluminum you can get at the home center. A little busy work, but the results were nice. I inserted threaded rivets into the panels, and used the standard strut hold downs within the struts.

No1Hunter · 10-03-2022, 06:01 PM

Wow, thanks for the in-depth response, Todd. It gives me some great ideas!

tinglett · 10-03-2022, 06:14 PM

Quote:

Originally Posted by No1Hunter

Wow, thanks for the in-depth response, Todd. It gives me some great ideas!

No problem at all. I was dragging my feet for quite some time as I really didn't want to be drilling into the roof. On the other hand, I have replaced both my fans and let me tell you about a pile of screws that involves!

If you haven't found the strut at the home center, just search for strut channel in their web page and you'll see it. You also want "cone nuts" like this: https://www.homedepot.com/p/Superstr...4-10/202077349 rather than the ones with the big springs. I figured that out the hard way. The little plastic cone bit just holds it in place so it doesn't move around while you line things up.

You could see from the earlier photos that I made little wood spacer bars to hold the struts exactly 2 feet apart (fairly arbitrary distance but worked good). I laid them in position and then drilled into the roof where I was going to shoot in the screws (this took some nerve). The rafters on my rig are 16" on center and the seams of the TPO are along rafters so some are easy to find. Also, in the morning with dew on the roof, the rafters were easy to see (see attached photo -- you can see them). I used little finish nails to help me align the super-sticky-spacers into place, and kept those nails in place to let me align and stick down the structs onto the spacers. Only then I pulled out the gooey nails and shot in the screws with little hold down plates I made. Hopefully that makes sense.

(Maybe this needed another thread. Sorry to the OP

, and back to the regularly scheduled program!)

No1Hunter · 10-03-2022, 08:56 PM

Thanks again Todd.

Now, back to the original subject:

1 - 190watt panel on roof

In the process of adding:

1 - 190 watt panel on roof

2 - 110 watt portable panels

I can't and will not be doing much until my TT gets back from the warranty work and my roof issue is addressed. Just stacking parts right now! LOL

DustyDude · 10-05-2022, 03:57 PM

I installed some flexible panels on the rubber roof of my previous class C by following Brian's video a few years ago (RV with Tito DIY). This is the updated version.

https://www.youtube.com/watch?v=uJIE...iXNPwgHDONvb89

I liked his idea of placing coroplast (plastic cardboard) between the roof and the panel to provide ventilation. I used 3M two sided tape to hold the 6 attachment points to the roof and then covered that with eternabond. The panel was then held on with 6 carriage bolts and nuts. I put a wingnut on top to make sure it didn't vibrate off. It held up well for more than 15,000 miles until I traded it off.

jonnyr1 · 10-14-2022, 04:57 PM

Quote:

Originally Posted by MicroMinnie

540w 3 x 180w panels
2 x 100ah

I apologize for going slightly off topic. I'd love to know how you wired the batteries in. I'm about to take ownership of a Minni 2301BHS and would like to add two lithium batteries.

As for the thread subject, current Micro Mini 2100BH has a 90w + hard 100W panel on the default solar charge controller. New Minni 2301BHS will come with the 200W, I'd like to add another 200W in the new year.

Edit, forgot the 190w suitcase too

bostonmary · 11-20-2022, 05:30 PM

Questions. Have you noticed any galvanic reaction between aluminum and galvy struts? Did you attach struts to plywood with wood screws or to aluminum? roof struts?

MicroMinnie · 11-20-2022, 05:35 PM

Sorry for delay

Pulled the wires back from front off trailer into storage, hooked up the 2 batteries inside

tinglett · 11-24-2022, 06:21 AM

Quote:

Originally Posted by bostonmary

Questions. Have you noticed any galvanic reaction between aluminum and galvy struts? Did you attach struts to plywood with wood screws or to aluminum? roof struts?

I'll keep an eye on this, but I suspect this will take a long time to become a real issue. And then, will a reaction just weld the parts together more, or decay them so they fail? I really don't know.

The screws I installed hit what I believe are aluminum roof struts that make the bow shape of the roof. The wood layer under the TPO is very thin, and you can see the layers if you remove a vent cover on the inside.

lenore · 11-24-2022, 08:43 AM

I found the same on my Vita, the wood substrate is like 1/8 inch if that. I used aluminum T track rails and like you didnt trust the TPO with tape. So I did use the tape, but used Well Nuts for the three screws in a 4 foot T track. The Well nuts are coated with sealant and once you tighten the screws in the track they expand under the thin wood substrate providing incredible holding power without ripping the wood. Screws in my original solar panels would rip easily and many have lost their solar panels while going down the road. So far with 9k miles this seems to be a very solid solution to Tito's system. I also lined the exterior of the rails with sealant to prevent water instrusion under the track. I used 100 Watt Renogy panels to replace the original flex panels.

BobC · 11-24-2022, 10:26 AM

If anyone is concerned about galvanic corrosion, vinyl electrical tape will work. That's what we used on our sailboats between stainless fittings and aluminum masts and booms. It will last forever. A good coating of sealant will work on screws.

Also, even with a solid roof, fastening with Eternabond isn't a good method, it's a sticky sealant, not an adhesive. The best thing for fastening things together is 3m VHB tape. It's used industrially for fastening sidewalls to trailer framing, etc:

https://www.3m.com/3M/en_US/vhb-tapes-us/

tinglett · 11-24-2022, 12:35 PM

Quote:

Originally Posted by BobC

If anyone is concerned about galvanic corrosion, vinyl electrical tape will work. That's what we used on our sailboats between stainless fittings and aluminum masts and booms. It will last forever. A good coating of sealant will work on screws.

Also, even with a solid roof, fastening with Eternabond isn't a good method, it's a sticky sealant, not an adhesive. The best thing for fastening things together is 3m VHB tape. It's used industrially for fastening sidewalls to trailer framing, etc:

https://www.3m.com/3M/en_US/vhb-tapes-us/

Just as I was deciding I didn't dare trust the TPO to hold the rails, I was also learning that Eternabond is not an adhesive. Boy, would that have been a mistake! I was going to order up some VHB, and the many choices slowed me down and made me think more about using screws.

I suspect the Eternabond layer between my aluminum spacers and galvanized struts will save me from the corrosion. What happens with this corrosion, though? Does the metal wear away quickly, does it take a zillion years, or maybe it just makes them stick? Just curious.

And happy thanksgiving!!

BobC · 11-24-2022, 05:09 PM

The Eternabond layer should be enough. The corrosion can be pretty significant in a marine or coastal environment but not too bad in most places.

I used this VHB to mount a solar panel on my fiberglass van roof and it's holding strong after two years:

https://amazon.com/gp/product/B01BU7...?ie=UTF8&psc=1

I've used it for numerous applications on the MH and around the house. You'll wonder how you ever did without it.

Senior · 11-26-2022, 02:05 PM

Quote:

Originally Posted by Winnie1800BH

On roof, plug into side, MPPT capacity?

What 'cha got?

correct answer: the factor installed 100w single panel on the roof that came with our 2021 2108FBS.

right answer: not enough.

bostonmary · 12-13-2022, 07:51 AM

Hello, desperately need info! How did you attach panels on roof? Are the screwed in?( I cannot find info on where my roof rafters are.) Or glued onto the roof? I believe the exterior roof material is glued to styrofoam.

bostonmary · 12-13-2022, 07:54 AM

Question for Micro Minnie, need info! How did you attach panels on roof? Are the screwed in?( I cannot find info on where my roof rafters are.) Or glued onto the roof? I believe the exterior roof material is glued to styrofoam.

Fred 2106DS · 12-13-2022, 10:35 AM

Quote:

Originally Posted by bostonmary

Question for Micro Minnie, need info! How did you attach panels on roof? Are the screwed in?( I cannot find info on where my roof rafters are.) Or glued onto the roof? I believe the exterior roof material is glued to styrofoam.

I used AM Solar rocker foot mounts. They come with 3M VHB tape on the bottom and #10x3/4" SS screws. I first stuck them to the roof using the VHB tape and then using two #10x3/4" screws, screwed through the holes in the bracket into the roof sheathing, then finished them off by covering the foot and surrounding area with self leveling dicor. The roof sheathing on my Micro Minnie is 7mm (~1/4"). I didn't worry about whether or not I screwed into a rafter. I haven't had any issues with the brackets pulling loose. My fore and aft panels have been on the roof since 4/2018 and the left and right panels have been on since 8/2021.