diy solar

diy solar

6000XP and 8 Aptos 370W Solar Panels

MattMan119

MattMan119

Solar Geek
Joined
Jun 12, 2024
Messages
86
Location
Merritt Island, FL
Working on a solar system this weekend, and wanted to get an idea what the thoughts are on the solar array configuration .. I'm sure there is a correct answer and would like to make sure I have it ...

I am installing 8 Aptos 370W 41.4V 11.26A Solar Panels and connecting them to the 6000XP

They are going to be connected to 3 EG4 LifePower4 100AH 48V batteries..

I would like to know what is the best configuration ..

1) 1 String 8 Panels -- 331.2V and 11.26A @ 2960
2) 2 String 4 Panels Each -- 165.6V and 11.26A @ 1480W each

I would think the #1 option as Nominal 320V for MPPT on 6000XP .. But not sure I know what I am talking about..

Thanks
Matt
 
Brucey said:
I would go with the 8 string assuming shading is not an issue.
Click to expand...
Yes, i was thinking the same thing.. Get over the 120V min faster .. I don't think shade will be a problem but if it is I will have the second feed there and can split the two .. It's only a 15ft run for them so should not matter much except they may hit min faster?
 
I have basically this exact setup -- primary string of 9 panels, with another string of 9 propped up against the house (not optimal but it's what I've got to work with)

Very pleased with my setup - it made it through the recent pretty terrible TX storms (and wind) we had that left 600k people without power for multiple days. Yay solar+battery backup.
 

Attachments

  • 1.jpg
    1.jpg
    612.5 KB · Views: 22
dfw_dude said:
I have basically this exact setup -- primary string of 9 panels, with another string of 9 propped up against the house (not optimal but it's what I've got to work with)

Very pleased with my setup - it made it through the recent pretty terrible TX storms (and wind) we had that left 600k people without power for multiple days. Yay solar+battery backup.
Click to expand...
Perfect… seeing anything from the bifacial back side of panels? (I know it would hard to tell .. but anything over 370x9 ever?
 
#1 for sure.

One thing to consider is that the manual for the 6000xp states that when sizing the strings for each MPPT, the panels must be the same model, brand and # per string. Since you can likely run a single string up to 10-12 of the 370w panels on a single MPPT, to be able to get max power out of the MPPT input, you might consider buying 3-4 more of the Aptos panels now since panel brands and models are constantly being discontinued and changed. You might not be able to get the name panels later.
 
MattMan119 said:
Perfect… seeing anything from the bifacial back side of panels? (I know it would hard to tell .. but anything over 370x9 ever?
Click to expand...
Maybe? So it's a string of 9 Aptos 370W panels, and the peak production is shown below. Which is 326W per panel, 88% of it's "regular" advertised.

Most people say expect 80% of advertised watt level, so the ground mount setup about 5' off the ground say 8% boost? no way to scientifically quantify it really, just ball park for the best part of the day.
 

Attachments

  • 1111.jpg
    1111.jpg
    41.5 KB · Views: 4
MattMan119 said:
Yes, I own 12 just can’t get more than 8 on the RV … although I got 4 extra so I can try again, what will take creative placement and I want to make sure they are safe and secure…. Thanks
Click to expand...
Sorry, I missed the RV part. Just curious, what kind of RV uses a 240v split phase electrical system? Must be bigger than any I’ve ever owned. Oh, sorry must be 50 amp.
 
MattMan119 said:
Thanks Eric,

The reasoning is the higher power less loss? I like to understand the theory behind it.. or optimal or inverter? Or both? Just curious why it is better..
Click to expand...
The main reason is you wouldn't want to be too close to the minimum required voltage per MPPT. A cloudy day could drop the voltage below the minimum voltage and the MPPT's would not operate due to insufficient voltage.
 
There is a lot of 50a split RV these days …
a I have attached a picture of my break box.. It’s a 2019 Forest River Sabre Cobalt

Now that said, they do not have any 220v fuses as you can see from breaker box, it’s used like two 50a 110 lines..

MattIMG_9416.jpeg
 
EG4_Eric said:
The main reason is you wouldn't want to be too close to the minimum required voltage per MPPT. A cloudy day could drop the voltage below the minimum voltage and the MPPT's would not operate due to insufficient voltage.
Click to expand...
Yes that is what I figured, I will be setting up 8 in one string, but may just run a few test for fun after I have it all done.. I am running two lines to roof anyhow just to make sure I don’t have to do it in the future.. so I can test pretty easy, but I suspect the one line is the most optimal configuration .. thanks
 
A quick question, you are using the bi-facial panels that I have but I was concerned about over loading the mppt with the bi-facial gain of sunny days with snow on the ground. I know there needs to be a measure of safety added in to the calculations to prevent this, have you taken that into consideration? Not questioning your plans here I'm just trying to learn before I build mine. I am using the same panels and inverter that you are so I really would like to know if 8 panels would cause this issue.
 
Yes
the spec are
Shamoke said:
A quick question, you are using the bi-facial panels that I have but I was concerned about over loading the mppt with the bi-facial gain of sunny days with snow on the ground. I know there needs to be a measure of safety added in to the calculations to prevent this, have you taken that into consideration? Not questioning your plans here I'm just trying to learn before I build mine. I am using the same panels and inverter that you are so I really would like to know if 8 panels would cause this issue.
Click to expand...
the power rating stays the same .. so that was not an issue the max watt output is 470 based on specs, I have seen them being flat mounted on RV 1in off, pull in 430watts but most.. so max should be #x470 = size … I have 8 so max is 3760, under my 4000 … but yes I would use the higher number …

IMG_4297.jpeg
So it will use max of 4000 … but notice the input can go over and just not be used.

IMG_4299.jpeg
Using voc 41.4x8 = 331.2 voc … I’m allergic to cold so that is way under 480v max

.. hope that answered you question … Will’s video on this really shows all the calculations and why …
 
Shamoke said:
A quick question, you are using the bi-facial panels that I have but I was concerned about over loading the mppt with the bi-facial gain of sunny days with snow on the ground. I know there needs to be a measure of safety added in to the calculations to prevent this, have you taken that into consideration? Not questioning your plans here I'm just trying to learn before I build mine. I am using the same panels and inverter that you are so I really would like to know if 8 panels would cause this issue.
Click to expand...
Bifacial gain shows up as additional current, it doesn't affect voltage.
 
Brucey said:
Bifacial gain shows up as additional current, it doesn't affect voltage.
Click to expand...
Hate to bug you @Brucey but could you kindly elaborate on this little detail or maybe send me a link that explains this? I'm also trying to size my my (larger) array and want to make sure I am planning this out correctly so as to not blow up my three inverters. Thank you!
 
JBoffgrid2022 said:
Hate to bug you @Brucey but could you kindly elaborate on this little detail or maybe send me a link that explains this? I'm also trying to size my my (larger) array and want to make sure I am planning this out correctly so as to not blow up my three inverters. Thank you!
Click to expand...
Someone had mentioned that they were concerned that the additional output from a bifacial panel in ideal conditions could cause Voc to increase beyond listed specs. But that's not the case, the extra power beyond the nominal primary side presents itself as additional current (amps). So you can just take the listed VOC and derate based on your coldest expected temperatures (as voltage increases as temps drop). Make sure you have adequate safety margin as exceeding the voltage rating of an SCC will generally cause the magic smoke to be released.
 
It will still increase voltage by maybe 1-2V but that ideally should be in the data sheet in the bifacial gain section and such increase can happen in high illumination (once in a blue moon edge lensing) situations too.
 
You must log in or register to reply here.

Similar threads

Snagler
EG4 6000XP Input/Panel String Question
Replies
7
Views
447
MattMan119
MattMan119
ScrotpusGobbleBottom
Aptos 370w panels. WOW
2
Replies
32
Views
1K
Casteil
C
E
Please advise me on expanding my system
Replies
7
Views
176
FilterGuy
FilterGuy
C
Can this charge controller and panels work 🤔
Replies
2
Views
127
Rocketman
R
R
Split 8 Panel Array into 2 Strings on 6000xp
Replies
2
Views
207
RoyGBiv
R

diy solar

diy solar
Back
Top