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High voltage cells (230v each) for a 40m run?

OffGridIdaho

OffGridIdaho

Hobby Farm in N Idaho
Joined
Jun 18, 2020
Messages
325
Location
N Idaho
Could I run these all in parallel to minimize tree shading on my cells. All panels would be in parallel and no series to knock the whole string down.
Using a victron 250/100

8 of these cells

Can someone advise of the pros/cons of doing this?

Specifications:

  • Power: 460W
  • Open Circuit Voltage (VOC): 222.9 V
  • Short Circuit Current (ISC): 2.59 A
  • Maximum Power Voltage (VMP): 188.8 V
  • Maximum Power Current (IMP): 2.44 A
  • Dimensions (inches): 79.09' x 48.50' x 1.93' in
  • Weight: 76.06 lbs.
  • Maximum Series Fuse Rating: 5.0 A
 
Shading doesn't knock a whole string down. Unless you have solar panels from 20 years ago. Solar panels now have built-in bypass diodes.
But yes, you can use whichever panels you want. As long as you can wire them to be compatible with your SCC. (Solar Charge Controller)
 
timselectric said:
Shading doesn't knock a whole string down. Unless you have solar panels from 20 years ago. Solar panels now have built-in bypass diodes.
But yes, you can use whichever panels you want. As long as you can wire them to be compatible with your SCC. (Solar Charge Controller)
Click to expand...
Huh.... Mine are 7 years old and it knocks them down hard, like 70%. Maybe its this crappy midnite kid. I see it dropping to zero constantly during a charge. Like 30x per hour. When there is NO shading. Plus the V calibration wanders. Can be off by 1.5v from resting no sun to full charge.
 
That sounds like a problem with wiring or SCC.
7 year old panels are definitely equipped with bypass diodes. You can confirm this, if you can access the junction box on the back of the panel.
 
No, it is not going to work. I'm surprised that responders can't figure that out. With a Voc of 223V at room temp, you are likely to bump up to 270-280V in the depth of winter. Having gone to school in Moscow, I know what an Idaho winter is like. That Voc is likely to fry your controller.
 
MichaelK said:
No, it is not going to work. I'm surprised that responders can't figure that out. With a Voc of 223V at room temp, you are likely to bump up to 270-280V in the depth of winter. Having gone to school in Moscow, I know what an Idaho winter is like. That Voc is likely to fry your controller.
Click to expand...

timselectric said:
As long as you can wire them to be compatible with your SCC. (Solar Charge Controller)
Click to expand...

I only replied to the question asked, regarding shading.
 
OffGridIdaho said:
Could I run these all in parallel to minimize tree shading on my cells. All panels would be in parallel and no series to knock the whole string down.
Using a victron 250/100

8 of these cells

Can someone advise of the pros/cons of doing this?

Specifications:

  • Power: 460W
  • Open Circuit Voltage (VOC): 222.9 V
  • Short Circuit Current (ISC): 2.59 A
  • Maximum Power Voltage (VMP): 188.8 V
  • Maximum Power Current (IMP): 2.44 A
  • Dimensions (inches): 79.09' x 48.50' x 1.93' in
  • Weight: 76.06 lbs.
  • Maximum Series Fuse Rating: 5.0 A
Click to expand...
Please provide a Link to the actual panels - those numbers are not quite right.
 
MichaelK said:
No, it is not going to work. I'm surprised that responders can't figure that out. With a Voc of 223V at room temp, you are likely to bump up to 270-280V in the depth of winter. Having gone to school in Moscow, I know what an Idaho winter is like. That Voc is likely to fry your controller.
Click to expand...
Wow, good thing I asked. I had no idea that V could climb by 60v. So under hyperVOC I should assume + 25% V?
Guess I will just get "normal" voltage range panels. I just thought running ALL panels in parrallel mode would help with tree shade sweeping my arrays.
 
OffGridIdaho said:
Wow, good thing I asked. I had no idea that V could climb by 60v. So under hyperVOC I should assume + 25% V?
Guess I will just get "normal" voltage range panels. I just thought running ALL panels in parrallel mode would help with tree shade sweeping my arrays.
Click to expand...
Have you considered plugging the numbers into the MPPT calculator for your brand of choice? Victron has one, Midnite has one.

More reliable than these comments imo, as long as you give them accurate temperature/spec data... Verify spec data was correctly read from panel labels for example rather than website summaries.

EDIT: And lets say these suggestions are perfectly correct, it also gives you a repeatable process next time you like a panel. It lets you run if/then analysis before you buy SCCs.

I want that Victron 250/100 MPPT, or a few of them!!!
 
Lilikoi_Heavy_Industries said:
Have you considered plugging the numbers into the MPPT calculator for your brand of choice? Victron has one, Midnite has one.

More reliable than these comments imo, as long as you give them accurate temperature/spec data... Verify spec data was correctly read from panel labels for example rather than website summaries.
Click to expand...
Victron doesnt show calculated end result just a picture of what they think will work SCC. Kind of lame if you ask me. Midnite shows calculated numbers but I have to choose their product. Im never going to use midnite again. Ive grown to dislike the Kid im using and its soured the milk.
The kid has soooo many niggly issues its very frustrating.
The most frustrating is the calibrated voltage changes from no amps resting to low amps to high amp charging. All three have a different calibrated voltage. Its impossible to charge Lifepo4's that way. Im buying a victron 250/100 first thing tomorrow morning.
 
OffGridIdaho said:
Victron doesnt show calculated end result just a picture of what they think will work SCC. Kind of lame if you ask me. Midnite shows calculated numbers but I have to choose their product. Im never going to use midnite again. Ive grown to dislike the Kid im using and its soured the milk.
The kid has soooo many niggly issues its very frustrating.
The most frustrating is the calibrated voltage changes from no amps resting to low amps to high amp charging. All three have a different calibrated voltage. Its impossible to charge Lifepo4's that way. Im buying a victron 250/100 first thing tomorrow morning.
Click to expand...
"just a picture of what they think will work"

It sounds like you didn't understand what the MPPT calculator does. It could have easily called out an overvoltage situation based on panel specs and the given temperatures. But since you didn't know that was an issue you make statements like the one above.
 
Lilikoi_Heavy_Industries said:
"just a picture of what they think will work"

It sounds like you didn't understand what the MPPT calculator does. It could have easily called out an overvoltage situation based on panel specs and the given temperatures. But since you didn't know that was an issue you make statements like the one above.
Click to expand...
Huh?
All it shows is a picture of what model it thinks will work, like 250/100. There are NO calculated charts of the results of the string calculation.
The midnite string calculator is much better but only for midnite products unless I want to decipher one to the other specs.
 
OffGridIdaho said:
Huh?
All it shows is a picture of what model it thinks will work, like 250/100. There are NO calculated charts of the results of the string calculation.
The midnite string calculator is much better but only for midnite products unless I want to decipher one to the other specs.
Click to expand...
If you change the MPPT calculator input to say that the PV module temp only goes down to 0F instead of -40F, it will tell you that you could use an MPPT 250/60. So you need to give correct information, and then it's very useful.

Did you try using this for this specific panel, or decide it wasn't good enough for you because it didn't show you as many numbers as midnite?

(needed for correct calc inputs)
 

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"didn't show you as many numbers as midnite?"

NEVER MIND I JUST SAW THE TINY BUTTON UNDER THE PICTURE
 

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sunsurfer said:
You also want to protect the strings from each other if you parallel them
Click to expand...
Yep, while a 250/100 will handle 29 of these panels paralleled, where is the string level protection in that build?

Maybe better with a 450/100 controller and build some normal half-cut panels into a high voltage string if you're trying to generate a small amount of power from a dark overcast sky? I'm making assumptions about Idaho winters being a driving factor in the design.
 
OffGridIdaho said:
"didn't show you as many numbers as midnite?"

IT DOESNT SHOW ANY NUMBERS!!!! NO INFORMATION AT ALL!!! JUST A PICTURE LIKE IVE SAID 3X NOW.

I GUESS YOU NEED A PICTURE TO UNDERSTAND SINCE YOU'RE GETTING CONDESCENDING ABOUT IT.

View attachment 121140
Click to expand...
Calm down please, grandpa. This isn't good for your heart and we care about you.

EDIT: I wish Victron MPPT calc showed more numbers too! And also no need to hide these ones behind a button. I'm sorry you had a poor user experience and think your feedback makes sense.
 

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OffGridIdaho said:
My bad, I was looking down the numbers page not under the tiny picture. I have a 4k screen and stuff is the size of a proton. I cant see tiny hidden stuff out of the way.
Click to expand...
I hope this helps your panel shopping! Totally get it I didn't find them the first time either.

The old excel version from Victron almost seems more techy if I remember correct. And it actually gets the new models added, the model specs feed in from one of the spreadsheet tabs, you can see ALL the math if you know how excel works,
 
Lilikoi_Heavy_Industries said:
I hope this helps your panel shopping! Totally get it I didn't find them the first time either.

The old excel version from Victron almost seems more techy if I remember correct. And it actually gets the new models added, the model specs feed in from one of the spreadsheet tabs, you can see ALL the math if you know how excel works,
Click to expand...
Anyways.......My apologies. Im fighting a bad headache and burning joints from severe rheumatoid arthritis. The $15,000/month medicine only helps about 40%. Not in a happy mood. I took it out on you, sorry.
 
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OffGridIdaho said:
Anyways.......My apologies. Im fighting a bad headache and burning joints from severe rheumatoid arthritis. The $15,000/month medicine only helps about 40%. Not in a happy mood. I took it out on your, sorry.
Click to expand...
Totally understandable! I hope the 250/100 works out great, I need to order one too.

But I think I want to keep it to a smaller number of strings, and ideally use circuit breakers in a midnite combiner box (6 strings?) so will probably look at more conventional panels.
 
Lilikoi_Heavy_Industries said:
Totally understandable! I hope the 250/100 works out great, I need to order one too.

But I think I want to keep it to a smaller number of strings, and ideally use circuit breakers in a midnite combiner box (6 strings?) so will probably look at more conventional panels.
Click to expand...
Yeah I have a midnite combiner. I need to ditch this kid and get a real scc. Ive calibrated the kid 3x today. It shows different voltage at different charge rates. The Jk is correct as tested by my expensive DMM.
midcalib.jpg
 
Lilikoi_Heavy_Industries said:
Tried replacing the wiring/lugs/etc connecting the midnite kid already?
Click to expand...
I did, two years ago. Its not big enough or the voltage granular enough to do what I want. It has multiple issues now.

Voltage only capable of 1/10th adjustments, example 27.x, not 27.xx
Main adjustment buttons wont respond when pushed
Jumps from back and forth from bulk/absorb when nothing is happening
Reboots sometimes without warning if you make a setting change, it goes right into bulk at 30 amps without warning, while it might have been in float before the boot, YIKES!!!
Voltage and amps cannot be calibrated
Gets very hot at full charge, needs computer fan not to fry itself
Ive seen it dumping 23 amps while in float mode, I mean WTF??? It kicked my JK off on HVP 3x in a row before I could shut it down.
Just fussy and not set it and forget it type scc.
Something fried my lead acid batteries and I have a good idea of who it was.

Not something you leave unattended.
 
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