Class C RV solar panel orientation question (for efficient wiring on roof)

[Ratchet1025]

Hello, I also posted this on the beginner forum, but thought I would try here as well.

I am a newbie, but plan to learn everything possible and appreciate your wisdom to make my system the best possible for my needs.

Studying so far: Explorist.life, Will Prowse, Solar Lab, Jasonoid and others

Things to do: Many, study wire size (thinking 10 gauge), getting all components, planning the wire runs inside the RV, etc.

Major Violations already:
1. Flexible solar panels purchased (no worries, I can change later if they do not work out)
2. Picking solar panels prior to knowing my needs (no worries again, this is a bit of an experiment for me and a fun project)

Question to the group:
Q). Considering the Solar panels I have, is this the best solar panel orientation (+,-) to reduce the length of wires and connectors on the roof as much as possible? The entry points to the roof are shown as EP1,2,3 for reference.

Happy to answer any questions as best as possible. I have my suit on, so feel free to roast me

 

[MisterSandals]

I also posted this on the beginner forum,

I will assume this gets answered there then if you double post.

 

[Ratchet1025]

I will assume this gets answered there then if you double post.

Sorry it did not get answered there, that is the reason for the repost. I will try to take the other one down. It was a few days ago.

 

[MisterSandals]

Question to the group:
Q). Considering the Solar panels I have,

Are the specs on these a secret? Are you showing Voc and Isc?

Are the 3 arrays of different voltages connected in parallel? (bad) Also would need fuses if 3P.

 

[Ratchet1025]

Apologies for the poor details given.

3 Arch 200W panels (each 17.1V, 11.7A) in series, total 51.3V <==> This feeds an Oupes Mega 3 Battery, thinking 1 15 amp fuse for this.

2 Ecoflow 100W panels (each 20.3V, 5.9A) in series, total 40.6V <==>This feeds an Oupes B2 Battery

2 Dokio 100W panels (each 18V, 5.6A) in series, total 36V <=>This feeds a 2nd Oupes B2 Battery

 

[Aussieguy]

I like to keep in the middle connect panels so you got around 50-60% of the rated controller voltage

wire length... on a roof full of obstructions is not possible to have perfect lengths etc more important to get as many panels up there as you can

I also don't like to use different sized panels (volts and amps) you might gain some watts by having a slightly bigger panel BUT risk loosing those watts due to voltage issues ...keep the voltages/amps outputs as close as possible as best you can

BUT do keep your............ controller to BATTERY wires .............as short as possible

2 x 370 watt panels in parrallel = 37v and 20 amps (they fit nicely side by side along the RV roof )
and keeps my batteries happy .

Found my panels on facebook .. 40 inches wide 9 bus brand new $175.00 each

NO idea what your Oupes likes to be fed I'd rather a decent battery and a stand alone MPPT

 

[HRTKD]

I don't worry much about the wire length. The most important thing is getting as much PV on the roof while avoiding shade. For your Arch 200w panels, if the trailer is parked as you noted then the leftmost panel will get shade much of the day, which isn't good since you have the panels in series. I would take those three panels and put them in line on the south side of the trailer, letting them hang over the shower hood an inch or two.

Then, buy three more of those panels and put them on the north side of the trailer, replacing the OEM Rich Solar if it's specs (Voc, Isc) are too far off from the Arch 200w.

This way you'll have at least one string that isn't in the shade from the A/C unit.

Each 3 panel string goes to it's own solar charge controller or put them in parallel to a larger solar charge controller.

 

[Ratchet1025]

Thank you all for the advice, the 3 200W panels are on the south/sunny side and should be in the best position in the storage facility where I park most of the time. Will definitely consider and study the additional recommendations.

 

[HRTKD]

Thank you all for the advice, the 3 200W panels are on the south/sunny side and should be in the best position in the storage facility where I park most of the time. Will definitely consider and study the additional recommendations.

I have to say that you're the first one I've heard that is laying out panels for when the RV is in storage.

 

[Ratchet1025]

Yes, sorry my meaning is I am using it, but between uses, it sits in a storage lot. One of the main purposes of the solar is to have the batteries fully charged prior to my usage (3~4 days without hookups at racetracks).

 

[HRTKD]

Yes, sorry my meaning is I am using it, but between uses, it sits in a storage lot. One of the main purposes of the solar is to have the batteries fully charged prior to my usage (3~4 days without hookups at racetracks).

I understand. Mine sits at the storage lot. With no loads on the system, staying fully charged isn't a problem except for when I have 12" of snow on the panels.

 

[MisterSandals]

Are there any solar charge controllers involved in this system?

 

[Ratchet1025]

Are there any solar charge controllers involved in this system?

The portable batteries have them built in..from their website…
MPPT: 18-140V, 15A Max (each of the 3 batteries have this information and the related inputs)

 

[Ratchet1025]

I understand. Mine sits at the storage lot. With no loads on the system, staying fully charged isn't a problem except for when I have 12" of snow on the panels.

Thank you, makes sense, I am very new to this!