Worried about Voc on Victron CC

[Primal1]

I'm looking to upgrade my Epever Tracer to a pair of Victron 75/15 smart solar mppts. The panels I want to use have a Voc of 24.50 and the Victron is rated to 75v will I be good running 3 of those panels on each CC? is that too close for Colorado winters and cold weather?

 

[LakeHouse]

I assume you mean three panels in series…
In which case, don’t do that. You’ll exceed the SCC’s 75V limit on even a moderately cool day.
Two in series would be fine.

 

[chrisski]

If a 12 volt system stem, 3P may work.

 

[Bob142]

Maybe pay a bit more and get two 100/15s? That'll give you plenty of headroom for a 3S panel config.

 

[squowse]

I'm looking to upgrade my Epever Tracer to a pair of Victron 75/15 smart solar mppts. The panels I want to use have a Voc of 24.50 and the Victron is rated to 75v will I be good running 3 of those panels on each CC? is that too close for Colorado winters and cold weather?

use a 100/15 instead. or a 100/30 instead of two 100/15

 

[Primal1]

use a 100/15 instead. or a 100/30 instead of two 100/15

My goal is to increase the number of panels to 6 to help my bank on bad solar days. It seems 2 smaller cc get the same job done at a lower cost and give me flexibility to move panels or CC if need be to another bank. A pair of 100/15 might be the ticket, thank you all.

 

[Primal1]

Just to make sure I'm not being an idiot. If I get 2 100/20 CC they will combine to charge at 40amps max, correct?

 

[LakeHouse]

Just to make sure I'm not being an idiot. If I get 2 100/20 CC they will combine to charge at 40amps max, correct?

If you have enough solar panels, yes.

 

[Primal1]

If you have enough solar panels, yes.

Excellent. Thank you. I found 100w panels with a 21.06.Voc so I figure 4 of those on each 100/20 CC should be perfect for my needs.

 

[chrisski]

6 panels on a 75/15 is good if you want to max it out all day.

I have 9 x 100 watt panels hooked 3s3p to a 75/15 at 24 volts. I see a lot of 15 amp charging with a max of 420 watts charging. 3 point east, 3 point west, and three point south.

 

[squowse]

My goal is to increase the number of panels to 6 to help my bank on bad solar days. It seems 2 smaller cc get the same job done at a lower cost and give me flexibility to move panels or CC if need be to another bank. A pair of 100/15 might be the ticket, thank you all.

2 x 100/15 is more £ than a 100/30 though

 

[squowse]

Excellent. Thank you. I found 100w panels with a 21.06.Voc so I figure 4 of those on each 100/20 CC should be perfect for my needs.

The lower voltage panels are much more expensive (per watt) than house panels (35-40V)

 

[Dominic]

Is there a benefit to go for 12v panels if you have to open circuit capacity?

Looking at mounting it in a work trailer

 

[chrisski]

Is there a benefit to go for 12v panels if you have to open circuit capacity?

Looking at mounting it in a work trailer

Not sure I know what you mean .

Most 12 volt panels out out 18 to 21 volts, so can hurt electronics. 12 volt panels mean more will work with a 12 volt PWM.

 

[JRH]

Just to make sure I'm not being an idiot. If I get 2 100/20 CC they will combine to charge at 40amps max, correct?

I would buy a pair of the 100/30 ‘s and look forward the day you want to add on more Pv.
We all do that in the end …..they are about 125 each or so +/- …it can’t hurt to have em..

 

[Dominic]

Essentially is it a

Not sure I know what you mean .

Most 12 volt panels out out 18 to 21 volts, so can hurt electronics. 12 volt panels mean more will work with a 12 volt PWM.

better option to get a 48v OC 400w panel.

I was just wondering whether the 12v panels were more robust for rv’s and trailers.. maybe better at taking a beating?

 

[chrisski]

Essentially is it a

better option to get a 48v OC 400w panel.

I was just wondering whether the 12v panels were more robust for rv’s and trailers.. maybe better at taking a beating?

I don’t think it matters much.

In my opinion because of shading, the 100 - 200 watt panels are better because of shading on the roof. At least I use them because of that on my roof to lessen loss from vents and ACs and skylights.