Hey RV Peeps - How did you find / select your solar panels?

[fratermus]

Spitballing: have you seen Sun Electronics in Miami Lakes yet? I've bought from them before with no problem. If you could swing a pallet you might be able to resell locally and get your own for free, effectively. Especially since no one is selling panels in your area. Arbitrage for the win.

Dunno about those particular Trinas, but I bought some well-used (ex-solarfarm) 250w Trinas that are performing very well for me.

 

[jvbutter01]

@willo

My process involved a couple shots of whisky and a few clicks on amazon.

been there done that many times for things, its amazing what shows up in the UPS / Amazon drivers next few days

@elpulpo

I mapped out the roof and then played with different configurations of 100W, 200W, 250W etc panels until I found the right balance. I used this sheet

thanks for sharing

@chrisski
is this automatic tilt, or a manual crank?

few questions,
1- I see comments about spacing, does anyone leave space to walk between them? I dont go up often, but if I do, dont need to be scaling the edge.

2- Ive got lots of space on my 33ft'er. Does anyone know about mounting brackets? do they come with

3- Ive seen some junction boxes in the past, any one have reviews on those to poke cables through the roof?

 

[Boondock Saint]

Hey . . go hijack your own thread :D

 

[jvbutter01]

oh sorry, not trying to hijack your thread, just have similar interest. need to get some panels on top of my TT also.

 

[cinergi]

I went with the Panasonic HIT 335's because they're a different form factor than typical 300+ watt panels and I was able to fit more on my RV roof (10 on a 38' 5th wheel) than I could with any other panel.

 

[Boondock Saint]

Thx, the ones in my post #20 physically fit and give me 2kw of panel, so at that price I'm OK to buy them. I was looking for any reasons not to before I pull the trigger on them.

 

[12VoltInstalls]

I have only tilted my panels once. Probably made a 40% difference in output.

That is a big difference!
I have seen a few videos where folks have measured stuff and their results were 5- or 10-percent difference vertical, occasionally 15% -20% or so flat. On big gangs of 100W polycrystalline panels. So I stopped worrying so much

One thing about cheap commodity 100W panels is if there’s a failure - you won’t be so far ‘down’ in power as the fewer-panel 400-watters.

 

[Boondock Saint]

I'm staring down 5 x 410w to fit and the possibility of 5 x $600 if I want to buy the tilt through Kevin.

 

[chrisski]

That is a big difference!
I have seen a few videos where folks have measured stuff and their results were 5- or 10-percent difference vertical, occasionally 15% -20% or so flat. On big gangs of 100W polycrystalline panels. So I stopped worrying so much

One thing about cheap commodity 100W panels is if there’s a failure - you won’t be so far ‘down’ in power as the fewer-panel 400-watters.

I think the date made a big difference with the sun lower in the sky when I did this test.

I measured this in December with the shortest day of the year, with the sun at perhaps 45 degrees So The sun is lower to the horizon . Now, I’m approaching the longest day of the year with the sun almost vertical in the sky, and I’m sure it would not be as extreme. I’m sitting in the RV now, and I could do this test tomorrow, but honestly, I don’t want to spend an hour and a half or more tilting the panels.

 

[HRTKD]

When I setup my ground deployed panels - a rare occurrence - I use an app to set the compass direction that they face and then the tilt angle. After that, I don't touch them until I go home, unless I inadvertently put them in the shade. I'm not there to get the 99% percentile of solar production. I'm there to have fun. Set it and forget it.

 

[Boondock Saint]

It's the final countdown (don't let that song stick in your head)

I have the 32 cells, I have another $6k of Victron and I need to pull the trigger on the panels purchase.

I'm still leaning toward the Trina 410's for fitment and price.

I'll have one string with 3 panels, and one with only 2, going to 2 SCC.

These will be in series so in my head the panels at the rear of the RV would be where I make the runs into my rig.

I'm a little stumped on which MC4 connectors / combiners to purchase to make these two runs.

I want premade between the panels and then make my own connections with cable to the SCC's.

With the panels running end to end on my rig, I can't connect the dots to have enough cable length and branch connectors for premade.

Thoughts, suggestions? Caffeine?


.

 

[curiouscarbon]

We are leaving ground, it’s the final count down… doo doo doo doo..

it is all your fault……


We head for venus..

what have you done… please help me

It’s the final countdown?

*charges batteries from power of sun*
*offers no useful advice due to lyrics saturating consciousness*

 

[HRTKD]

Are there vent fans close to where the PV panels will be? That may be the easiest way to bring wires into the vehicle. Take off the inner shroud of the vent and you may have access to the "attic". I ran my rear camera cable by going through the attic, using the vent openings (from the inside) to get the wire through. Put a roof gland near the vent.

 

[Boondock Saint]

Are there vent fans close to where the PV panels will be?

Yes, that's a given, but not the issue at hand. I'm looking for guidance on which premade Y-branch combiner interconnect thingies I need between panels 1 - 2 -3 to end up with a single positive and negative wire, and then repro that for panels 4 and 5.

Do I need qty = 2 of the combiners with 8' cord length for the first set, and just qty = 1 for the second pair? The connectors I see don't have long cable.

It's the THINGIES man, the t h i n g i e s . . .

 

[willo]

I made up custom cables for my PV runs and used a pair of 4-1 combiners.
My camper already had a MC4 rooftop connector.

On a non-pre-run setup, I'd install a junction box where I penetrated the roof, then run the PVs to bus bars inside the box.
Add cable glands to the box for the wiring runs to the panels. Seal the bejesus out of the box to roof surface.

 

[cinergi]

Since you're not combining strings, you don't need fuses or any special combiner box. Just like willo's setup. On my roof I have a simple electrical combiner box (I believe 2-gang deep plastic/outdoor-rated) where everything is joined for the home runs to the SCCs (I still need to install fuses - I have inline MC4 fuses for that). Bonus - the box covers the hole in the roof (hole is drilled in the back of the box to align with the hole in the roof).

 

[HRTKD]

Yes, that's a given, but not the issue at hand. I'm looking for guidance on which premade Y-branch combiner interconnect thingies I need between panels 1 - 2 -3 to end up with a single positive and negative wire, and then repro that for panels 4 and 5.

Do I need qty = 2 of the combiners with 8' cord length for the first set, and just qty = 1 for the second pair? The connectors I see don't have long cable.

It's the THINGIES man, the t h i n g i e s . . .

If you're running each string in series and then each string into its own solar charge controller, you don't need ANY Y connectors. Your obsession with the thingy is a little goofy.

 

[Boondock Saint]

OK so not a Y connector, M/F extender? Same concept, I need connectivity. The cables that come ON the panels are not long enough to reach each other. They will not be close enough end to end.

I have to connect from one end of the RV to the other. If you understand these are in series why didn't you just provide the correct answer.

How can I make it happen?


Will these 6' cables or the 10' version do what's need to hop panel to panel? I would then need a short run from the closer panels and a long run from the front of my rig and then make the runs all the way to the SCC?


.

 

[HRTKD]

If you understand these are in series why didn't you just provide the correct answer.

I'm lucky to remember my own name from day to day. I can't remember everyone's "plan". If you hadn't changed your plan 27 times, maybe I could remember it. Oh, wait, that was someone else.

You can try to buy pre-made cables. It's going to be an extension cable that you want. Male on one end, female on the other. But you need to know which end is which! Ha, just kidding.

Or, you could just suck it up and buy an MC4 crimper and bulk cable. If you already have a modular ratcheting crimper, then just an MC4 die will work. This is the one I bought, because I already had a Pro'skit ratcheting crimper.

Lunar Series Die Set for 4mm Solar Panel Contacts

Application:Multi-Contact ∅4mm Solar Contacts Crimp Size: AWG 14/12/10DIN 2.5/4.0/6.0mm²

eclipsetools.com

You may know the dimensions of the roof, but do you know how much cable it's going to take to run the cable down walls and across walls? I had a guess, but it was probably wrong. Running short on the extension cable will really, really suck. Plus, running a cable without an MC4 end on it through the walls is way easier than if it has the connector (i.e. bigger holes required, snags, etc).

 

[Boondock Saint]

If I use all premade on the roof M > F > M etc and get that correctly measured just before I enter the vent area, then it's a lot easier to get the remaining run right by over buying and padding. If I get near the vent/gland area I could use 50' runs and have some to spare.

So in summary, iiuc . . I will use 3' - 6' extensions between the panels in order to make the circuits, use 20' - 25' premade runs to get back to the vent from the furthest connections, and then use cable with connectors on one end near the vent and fish on down to the destination.

I'm appalled you can't recall my plan! It wasn't 27 times, I just couldn't keep getting straight answers! ?

Thank for helping clear this up before I have another ton of sh*t to return to somewhere.