Rethinking the SCC needs based on solar panel considerations

[Boondock Saint]

Howdy,

If I buy 5 of the Trina 410w panels, I would need to put 3 on one SCC and 2 on another, each tied to a 48v bank.

Originally I contemplated a 100A SCC but now that I see the panel specs, it seems unnecessary to be anywhere near that much rating.

If I take the first 3 panels I can be at around 150v, or I can put two of them in parallel for around 100v. The other 2 panels would also be around 100v in series.

Given this nominal requirement for each SCC, it seems more logical to only buy a 30A - 40A SCC that can work with a 48v battery.

Rated Power Output 410
Voltage (VOC) 51.2V

Sound right so far?

Could I not simply use something less expensive like this Victron Energy SmartSolar MPPT 150V 35 amp 12/24/36/48-Volt Solar Charge Controller ?

 

[MisterSandals]

If I take the first 3 panels I can be at around 150v, or I can put two of them in parallel for around 100v. The other 2 panels would also be around 100v in series.

Which of these are you asking about?

 

[Boondock Saint]

BOTH. I need a SCC for each banks of 48v.

Each side of my rig will have a 48v bank and a SCC. The only difference is how I supply the panels to them.

No matter how I supply the panels to them, I can't justify a 40A or higher SCC.

 

[HRTKD]

Odd numbers of panels are always a pain to deal with.

Two of those panels in series has the potential to produce almost 20 amps at 48v. You can go 2s2p, but then what do you do with the last panel? If you went with different controllers, one that can handle three panels in series and on that can handle two in series that would work. But the controller for the three panels in series would need to handle 200 volts of PV input. That won't be cheap.

 

[Boondock Saint]

Ok great, lets go w larger scc on both sides, what do you all suggest?

 

[HRTKD]

Voc = 51.2v

Victron 150/35 for the two panels in series

https://www.victronenergy.com/upload/documents/Datasheet-SmartSolar-charge-controller-MPPT-150-35-&-150-45-EN.pdf

Victron 250/70 for the three panels in series

https://www.victronenergy.com/upload/documents/Datasheet-BlueSolar-charge-controller-MPPT-250-70,-150-100-&-250-100-VE.Can-EN.pdf

If you were willing to ditch the fifth panel, the above controller would handle four panels wired in series. Alternatively, a smaller wattage panel might be enough to get you into two of the 150/35 controllers.

 

[Boondock Saint]

Thx, so a little less than the 100A aspiration I started w last year.

Regarding integrating shore power and a generator, are you familiar with the multiplus models? Same schema, one for each side.

 

[HRTKD]

I don't have a Multiplus myself, but have read up on it. If you don't already have an Automatic Transfer Switch (ATS) then you'll need one. The Multiplus has only one AC input. If you don't want to implement an ATS then consider the Quattro, which has two AC inputs.

Do you have two totally separate 48v systems? If so, I'm not sure how that's going to work with the AC input. I suppose one AC line in can be split to two Multiplus. There are Victron diagrams out there that show how to do that I think.

 

[Boondock Saint]

Not separate, just space constraints The 2 48v rails will be in parallel.

I have a 30A service but considering upgrading to 50A.

I just need to finally start buying and installing products. Thx for the advice.