Hello, I was hoping someone would chime in and help me configure my panel arrays for optimum production. I have two victron smart charge controllers 150/100 & 250/100. I have the following panels (10) 315 watt, (8) 230 watt, and (12) 100 watt (see pictures attached for more info). I have (16) 280ah Eve cells and two jk BMS. It's a 24v system. I have victron 24/3000/70 multiplus inverter/charger, cerbo gx, bmv-712, midnite solar combiner box. Not sure what else to add. Any help is appreciated. Thanks
Help me configure my panel arrays please
- Thread starter poorejj
- Start date
Hi. I'm no expert, but the only good way to set this up would be to add a 3rd controller so you don't have to mix up the panels.
250/100 would go with 230w panels 4s2p, 150/100 with the 315w in 2s5p and the 3rd controller with 100w ones in 4s3p.
I might be wrong also and I'm sure some more experienced users will correct me and guide you better.
250/100 would go with 230w panels 4s2p, 150/100 with the 315w in 2s5p and the 3rd controller with 100w ones in 4s3p.
I might be wrong also and I'm sure some more experienced users will correct me and guide you better.
21 x6 126V 2 strings
37 x3 111V
45.6 x 5 is 228
37 x3 111V
45.6 x 5 is 228
The 100W and the 230W panels can be paralleled together, but the 100’s will lose a bit from the merge.
The 315’s can go on the 250/100
The 315’s can go on the 250/100
I need to know the area you live in's record lowest temp to see if the panels can be pushed higher.
There is not much data on my area. The only source that I could find said 4 degrees was the record low. However there is a larger town about an hour away that says the record low there is -5 (Fahrenheit). Also another question I have is, how to I take advantage of the higher voltage input on the 250/100 charger when I can't find 250vdc breakers for my midnite solar breaker box?
3x2=6 so what about the other two panels
Yup, there are disadvantages to using low voltage charge controllers…
I appreciate you're help and advice... Did those numbers for temps change anything? Also what about the breaker for disconnect?
Yeah, -4 is COLD, you need to run the voltages I listed through a calculator to be sure they won’t overvoltage the controller.
Ok... Yeah it usually doesn't get so cold around here, that was just the record. I'm in Northeast Texas.
Yup, the record is what you have to size for...
Because it WILL happen, and your controller will fail.
Can I mix different panels in one string? For instance, using victrons mppt sizing calculator it looks like I should do strings of 4 with the 315 watt panels I have. That leaves me with 2 extra panels. Could I do a string on the other controller with 2x 315 and 1x 100 (45.6x2+21=112.2) in parallel with the 3x 230 (37x3=111) panels?
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When mixing different panels (really this is for any panels -same or different);
(Using Vmp and Imp numbers)
When in Series the volts add and you use the lowest amps.
When in parallel the amps add and you use the lowest volts.
You figure out each string - then if you combine strings together you run it through the same calculation.
Finally Volts * Amps = Watts
Then you can figure out the penalty for connecting different panels together- some penalties are small - some are so big it doesn’t make sense.
Also double check the Voc to make sure the record cold temp does not cause the Voc voltage to go above the input limit- as temps drop the panels produce more voltage. If you go above the limit it will destroy your solar charge controller one cold winter morning.
I will let you do the math for putting a 315w panel in parallel with a 100w panel. Hint:it will not be good - but run the math to understand…
(Using Vmp and Imp numbers)
When in Series the volts add and you use the lowest amps.
When in parallel the amps add and you use the lowest volts.
You figure out each string - then if you combine strings together you run it through the same calculation.
Finally Volts * Amps = Watts
Then you can figure out the penalty for connecting different panels together- some penalties are small - some are so big it doesn’t make sense.
Also double check the Voc to make sure the record cold temp does not cause the Voc voltage to go above the input limit- as temps drop the panels produce more voltage. If you go above the limit it will destroy your solar charge controller one cold winter morning.
I will let you do the math for putting a 315w panel in parallel with a 100w panel. Hint:it will not be good - but run the math to understand…
So if I'm understanding correctly then, if I'm going to mix panels at all it probably will make the most sense to keep the 100 watt panels in their own separate strings that are slightly higher in voltage than the larger panels so that my loss is from the 100 watt panels and isn't so great a loss. For instance if I have an array of the 230 watt panels, 3 of them in series, the vmp adds up to 89.4 volts. If I parallel that with a string of 5x 100 watt panels, the vmp adds up to 90 volts. So the 100 watt string would take that loss of .6 volts, but the amps would still be added. Is that correct?
No, the lowest voltage wins.
Yeah, i misread the question... long day.
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