first 24v

[jBrew]

If you plug the numbers into Victron's MPPT calculator you will see that the SCC could generate up to 37A output with those panels.


According to Victron's MPPT calculator, if you go 2S2P with those panels you will want the 150/35. If you go 1S4P you will want the 100/50. The 100/30 would work at 4P but you would be giving up some amps so going with the 100/50 lets you take full advantage of the amps it can generate with the panels. And it gives you room to upgrade to 5P if you wanted.



Between the SCC and the battery you have 20 feet of wire round trip. If you use the 100/30 or the 150/35 you need 6AWG to safely pass 30A or 35A over 20'. If you go to the 100/50 then you want 4AWG to pass up to 50A over 20'. But the 100/50 only accepts up to 6AWG so I'm not sure how that works.

so here is the calculator for 2S2P: suggested 150|35 by calculator

and here is for 1S4P: suggested 100|30 by calculator

where can i find the 37 amps?

 

[rmaddy]

where can i find the 37 amps?

Download their spreadsheet calculator so you can see the actual numbers and all of the calculations. Once you enter your custom panels and then enter the right values for your setup you can look at the calculations tab. Since the numbers get truncated to the Mac current of the selected SCC you usually need to select a larger SCC to see the non-truncated values.

 

[jBrew]

Download their spreadsheet calculator so you can see the actual numbers and all of the calculations. Once you enter your custom panels and then enter the right values for your setup you can look at the calculations tab. Since the numbers get truncated to the Mac current of the selected SCC you usually need to select a larger SCC to see the non-truncated values.

can you send over the link for the spreadsheet calculator

 

[rmaddy]

can you send over the link for the spreadsheet calculator

It's on the main SCC page:

Solar Charge Controllers - Victron Energy

Get the highest attainable efficiency from sunlight, even if it is limited, with the solar charge controllers from Victron Energy. Find a dealer nearby.

www.victronenergy.com

In the text at the top is a mention and link of the MPPT Excel sheet.

 

[Northernchateau]

It's the output of the SCC, not the current of the panels. Plug the numbers into the Victron MPPT calculator and you will see what I'm talking about. It's labeled "Ibat max @ Impp" (maximum battery current at panel maximum power point current).

The potential Ibat max @ Impp will be capped at the max current of the SCC (30A for a 100/30 MPPT SCC for example).

The rough formula is string Vmpp times Impp divided by system voltage where each of those first two values is adjusted for temperature. In this case (2S2P), at STC, Vmpp = 75.2V (2S), Impp = 10.72A (2P), system voltage = 24V.

75.2V * 10.72A / 24V = 33.6A

At -5ºC it works out to about 37A.

Ok, now I see you said "Those panels in 2S2P can also generate close to 37A output from the SCC"
It really has nothing to do with how the panels are configures but their total power output.
Lets do Solar math:
200 watts x 4 panels = 800 watts
800 watts / 12 v = 66.67 amps ( from SCC )
800 watts / 24v = 33.33 amps )from SCC )
So Jbrew that means you need a bigger Victron solar charge controller no matter how you slice it.
How big will depend on if you run a 12 v or 24v system.

 

[Wibla]

The 100|30 will be fine for 800W at 24V. OP might* experience a little bit of clipping, but it will most likely not be noticeable at all on overall energy output.

*remember that solar panels very rarely hit their actual peak output for any length of time, unless they're mounted to a dual-axis tracker and the weather is perfect.