School Me on Solar Panels

[TurnThePage]

I recent started a thread about lifepo4 battery configurations, 12v/24v/etc. I think I'm settling on four 230 AH batteries, and will likely keep them in a 12v config.

Now I want to figure out the solar. I am mounting the panels in a permanent position on the roof with no adjusting for best sun.
I see lots of systems where they are very close to the roof and wonder about that. Panels get hot. My intention is to run tracks the length of the roof and mount on them, maybe keeping the panels 4-6 inches off the roof. That will provide good ventilation and even shade for the RV. It will also reduce shadows on the panels from other stuff on the roof.

Now my questions:

I'm not familiar with current wiring methodology. Are they all the same now? I hear people mention MC4 connectors. Is that the standard? Do I need to worry about that or will all the hardware be compatible right out of the box?

What about the panels themselves? I've understood that monocrystalline is superior to poly for RV use. Is that still the case? It sounds like most panels are manufactured with shade tolerant diodes built in now. What other considerations are there?

[Vintage465]

TurnThePage wrote:
I recent started a thread about lifepo4 battery configurations, 12v/24v/etc. I think I'm settling on four 230 AH batteries, and will likely keep them in a 12v config.

Now I want to figure out the solar. I am mounting the panels in a permanent position on the roof with no adjusting for best sun.
I see lots of systems where they are very close to the roof and wonder about that. Panels get hot. My intention is to run tracks the length of the roof and mount on them, maybe keeping the panels 4-6 inches off the roof. That will provide good ventilation and even shade for the RV. It will also reduce shadows on the panels from other stuff on the roof.

Now my questions:

I'm not familiar with current wiring methodology. Are they all the same now? I hear people mention MC4 connectors. Is that the standard? Do I need to worry about that or will all the hardware be compatible right out of the box?

What about the panels themselves? I've understood that monocrystalline is superior to poly for RV use. Is that still the case? It sounds like most panels are manufactured with shade tolerant diodes built in now. What other considerations are there?

I'm not a fan of MC4 connectors. I think most people like them because that's what most panels come with and there are many branch connectors and thins to tie the panels together. Personally I think thers a lot of fittings to get stuff connected that you can just do with a combiner box, lugs and water proof crimp connectors. I just think it's a lot cleaner, tidy-er and less joints for things to go sideways.

[TurnThePage]

Good advice! After further reading I have to completely agree. Unfortunately I don't have a fridge chimney on the new rig.

[pianotuna]

TurnThePage,

150 volts may not be a good plan. 250 yes would be fine.

The fridge Chimney is the easy way to upgrade the wire size.

[TurnThePage]

Maybe a Victron "SmartSolar MPPT 150/70 up to 250/100 VE.Can" The total open voltage of the panels I'm looking at is just over 151 volts.

I know that's some expensive hardware, but it might be worth it for me to keep installation effort to a minimum. I just don't know if I want to open the roof and try to route more wire. I already have gimpy shoulders and knees.

[pianotuna]

TurnThePage,

Which charge controller have you decided on?

Be sure to wire the batteries in a balanced manner.

[time2roll]

groundhogy wrote:
Mount panels to top of RV, and you have to have RV in sun.

With enough panels the RV is always shaded. (at least on the top)

[TurnThePage]

I go to Amazon for almost everything and never even thought to look there for that! Thanks!

[Cptnvideo]

When I added 2 more 206ah batteries, I bought ready made 4-0 cable from Amazon. I bought 2 12" and 2 18" flexible welding type with connectors installed.

[TurnThePage]

groundhogy wrote:
Mount panels to top of RV, and you have to have RV in sun.

Guess I'll just have to deal with it. I'm putting 7 panels up there. NO WAY I'm going to goof with 7 panels on the ground so I can park in the shade. Besides I won't be pulling that much power most of the time. The number of panels is intended to offset shaded or partially shaded scenarios too.

So... 920AH of lifepo4 batteries arrive tomorrow. Now to get serious about the other hardware. I found a Victron 3000 watt Multplus that will arrive preprogrammed for my set up. I have a few other expensive pieces to put in place too.

Where do you guys get the support hardware? Cables, bus bars, connectors, etc.? I think I would like to order the big cables pre-cut and connectorized.

[pianotuna]

Dusty R wrote:
Different areas have different amounts of sun shine.
Michigan ranks 47th of the 48 Continental States.
So how long would it take for Solar Panels to pay for them selfs, in Michigan?

Most solar systems in Michigan pay for themselves with utility bill savings in 9 to 12 years, but the lifespan of solar systems is usually between 25 and 30 years.Mar 2, 2023

https://www.greenlancer.com/post/going-solar-in-michigan

[Dusty_R]

Different areas have different amounts of sun shine.
Michigan ranks 47th of the 48 Continental States.
So how long would it take for Solar Panels to pay for them selfs, in Michigan?

[groundhogy]

Mount panels to top of RV, and you have to have RV in sun.

[StirCrazy]

Like Richard said, I also recommend 24V panels and if you can find them split cell design. more efficient, more shade tolerant and so on. As for tilting, I don't worry much about that as it is rare where I camp that I can ensure I am facing the right direction to take advantage of the tilt and it is a hassle to climb up and do it. Also, a moving mount puts a weak spot in the system. I like your idea of building a rack setup.

[pianotuna]

TurnThePage,

This page may help:

https://freecampsites.net/adding-solar/