Solar/Lithium For Micro Minnie - Page 2

Ret.LEO · 07-09-2021, 04:20 PM

Quote:

Originally Posted by Marine359

LEO going big on solar may never need to run a generator, but where will you put all the panels?

That is kind of a "wait & see" thing. I'm thinking of cutting cardboard pieces the size of a couple different rigid panels I'm considering and see what fits where. If needed I can cut back to 4-100 watt panels on the roof and "pony up" for a portable 200 watt suitcase.

Ret.LEO · 07-09-2021, 04:32 PM

Getting down to basics: I would guess that Winn. uses wood trusses in the roof and have you found them to be on 16" centers?
Thanks to everybody for your thoughts and help

On a humorous side note: Why did I spend all that money for my middle boy to be a Civil Engineer? A Electrical Engineer would be a great help in this endeavor

He designs waste treatment plants for municipalities........might be handy if I have gray & black tank issues

The oldest is a Nuclear Engineer......no help at all

tinglett · 07-09-2021, 06:27 PM

Send a note to [email protected] and ask if they have "roof assembly" and "solar wiring" diagrams for your trailer. Give them the model number, and I'd also include the VIN so they know you really are an owner and they can cross-check to make sure you get the right print. You'll get PDFs within a day! They ask that you don't distribute them, which does make sense.

I was thinking the trusses were aluminum, but I'm not positive. Mine for sure are 16" on center and can actually be seen quite easily in the morning when there is dew on the trailer.

Marine359 · 07-23-2021, 11:03 AM

I’d like to add 200w of solar to the roof. Which is better?
One 200w panel, or 2x 100w panels in series?

dhodgesnvl · 07-25-2021, 03:28 PM

Hi again DavidM. Why do they need to be even numbers? Mine are but not on purpose.

Fred 2106DS · 07-25-2021, 03:32 PM

Quote:

Originally Posted by Marine359

I’d like to add 200w of solar to the roof. Which is better?
One 200w panel, or 2x 100w panels in series?

Jim, Here are my opinions, they assume your roof layout is similar to my 2106DS.

If, I was only looking to add 200 watts to the roof, I would opt for 2x 100w panels in parallel, one in front of the AC and one behind, being aware of the placement to minimize anything that could possibly cast a shadow (AC cover, vent covers or antennas). Even a very small shadow on a panel can easily cost you at least 30% of that panel's output.

A single 200w panel placed behind the AC would be an option if I was thinking of adding an additional 100w panel in the future. This additional panel would go in front of the AC. This would also be a parallel connection. The wiring from the roof gland to solar controller would need to be able to handle the 300w.

I would not consider 2x 100w panels in series, unless the wiring from the roof gland to solar controller was so small it could not handle the current from a parallel setup. Shadows on one panel in the series can take down the whole series.

These opinions are based on my reasoning and research from when I installed my rooftop panels, a 180w behind and a 100w in front of the AC. This placement also allows ample room for moving around the roof for cleaning, maintenance, etc.

One other thing, I opted for the tallest mounting brackets I could at the time to help minimize any shadows from the AC and vent covers.

backtrack15 · 07-25-2021, 04:34 PM

Quote:

Originally Posted by Marine359

I’d like to add 200w of solar to the roof. Which is better?
One 200w panel, or 2x 100w panels in series?

I chose to go with 2x 100W in parallel. I started with one and added the second later (when my allowance built up again). One is up front on the street side of the front roof vent. The other is centered on the roof between the AC and the bathroom vent. This arrangement gives me easy access to everything for maintenance.

Elkman · 07-27-2021, 01:33 PM

Higher wattage panels are more efficient but also much larger in size, OK for a house and maybe a trailer but not with a motorhome. With my Navion I cut pieces of cardboard the size of the 100W and 190W panels I planned to add and then could lay them on the roof to verify there was space and to look for shading of the panels by other stuff on the roof, like the AC unit and Winegard antenna enclosure.

The controller needs voltage coming from the panels to be in the same range. Best to check the Watts that the solar charge controller can handle as this is otherwise an added expense. The Zamp kits that Winnebago uses have a controller rated for up to 510 Watts and this is also the rating for the 3-port roof cap. With 4 panels and three ports with the roof cap I opted to join the two factory installed 100W panels to provide a parallel 200W feed to one port and use the remaining ports for the two panels being added.

There are a number of options for adding feet that use VHB tape to secure them to a fiberglass roof. It is only with a TPO membrane or similar 2-part roof that screws are needed. The weight of the panels is only around 20 lbs and no significant uplifting from driving at freeway speeds so each foot is only handing a 5 lb load or you can go crazy and use 6 feet per panel.

BobC · 07-27-2021, 03:19 PM

The fiberglass roofs on Winnebagos are thin Filon. I've read conflicting postings about whether or not it's glued to the underlying Luan. I know that AZ Expert glues the Filon down when he does roof replacements.

In either case, on my 2002, the Filon doesn't seem to be uniformly secured to the Luan. This could be due to age, but, in any case, when I mount my panels I don't think I want to just trust VHB tape. I did use VHB on my E350 van but it has a laminated fiberglass top.

I do agree with Elkman that the loads exerted by solar panels are relatively small.

BobC · 07-27-2021, 03:29 PM

Quote:

Originally Posted by Marine359

I’d like to add 200w of solar to the roof. Which is better?
One 200w panel, or 2x 100w panels in series?

I went with two 160W panels for a total of 320W without taking up too much more real estate than two 100W panels. In any case parallel is the way to go.

Marine359 · 07-27-2021, 03:30 PM

Quote:

Originally Posted by BobC

I went with two 160W panels for a total of 320W without taking up too much more real estate than two 100W panels. In any case parallel is the way to go.

Will 100/20 mppt be enough or would that need 100/30?

BobC · 07-27-2021, 06:51 PM

If you're considering a Victron 100/20, pg 13 of its manual states its capacity at:

12V - 290W
24V - 580W

https://www.solar-electric.com/lib/w...-15_100-20.pdf

Therefore, you're good at 200W either in parallel or series.

Ret.LEO · 07-28-2021, 08:34 AM

Wouldn't it be sweet if Will Prowse did installations? That young man is amazing! His YouTube video's are a huge source of knowledge. For us Lithium type people he just did a tear down video of a Li battery by the name of SOK, excellent quality that impressed him (hard to do) and it sells for close to 1/2 the price of a Battleborn:

https://www.youtube.com/watch?v=GRTmvjcLXxs

Ret.LEO · 07-28-2021, 08:41 AM

Quote:

Originally Posted by BobC

I went with two 160W panels for a total of 320W without taking up too much more real estate than two 100W panels. In any case parallel is the way to go.

When I spoke to ????? (horrible memory) at Win. he said three 160 watt panels would be the best way to go without changing things......... that with two Li's would be sweet, four Li's would be a dream.

BobC · 07-28-2021, 09:07 AM

Quote:

Originally Posted by Ret.LEO

Wouldn't it be sweet if Will Prowse did installations? That young man is amazing! His YouTube video's are a huge source of knowledge. For us Lithium type people he just did a tear down video of a Li battery by the name of SOK, excellent quality that impressed him (hard to do) and it sells for close to 1/2 the price of a Battleborn:

https://www.youtube.com/watch?v=GRTmvjcLXxs

Will is making too much money via Youtube to get his hands dirty doing installations. He's done well for himself, having gone from living in an RV to a nice house on Youtube income.

In this early video he tells a bit about his "story":

https://www.youtube.com/watch?v=P2BNsxMNqjo

Elkman · 07-28-2021, 10:26 AM

Solar panels may have a 12 volt VOc value but when operating the output is in the range of 17-21 volts DC. Wired in series two panels can be sending 35-40 volts to the charge controller and this is as important a spec as the Watts it can handle. The Zamp ZS-30A charge controller installed by Winebago for example is engineered for panel voltage of 15-22 volts and two panels wired in series would exceed this.