diy solar

diy solar

Solar Panel Shipment (another one...)

What if you gave the customer a defective product to begin with?
That is an entirely different issue, Here the issue is that ownership begins when buyer or his agent receives the goods. If owner or his agent transported them, the owner is responsible fro freight damage. That is standard commercial practice unless agreed to otherwise.
 
Ok i think I got confused, because I'm beyond the shipping portion, as there was no damage to the panel that affected the way the panel could operate as advertised.

I'm moving on to the portion of the sale where the panels are now underperforming compared to how they were advertised, and I would just like replacements.
 
Ok i think I got confused, because I'm beyond the shipping portion, as there was no damage to the panel that affected the way the panel could operate as advertised.

I'm moving on to the portion of the sale where the panels are now underperforming compared to how they were advertised, and I would just like replacements.
Was there a documented guarantee? Guarantee statement? Based on sun angle and out door temp?
Can you list the "solar panel checker" that you purchased?
I have bought a lot of used panels. About all that can be checked without hooking it up to a system with a load is the VOC.
Was this how they based their advertisement?
I asked SanTan what an acceptable range would be for testing panels, and all he said was if they are between 33-35v VOC, then they should be fine. Well, all 58 of my panels tested atleast 33v, including my 1x that was at 62w, so clearly this is NOT an acceptable way to test solar panels....
 
Was there a documented guarantee? Guarantee statement? Based on sun angle and out door temp?
No, there is not a documented guarantee, but it does say on their listing "Panels have been tested and have good output.". Would you consider 106w to be "good"?
Can you list the "solar panel checker" that you purchased?
I have bought a lot of used panels. About all that can be checked without hooking it up to a system with a load is the VOC.
Yes, the tester I have is a true MPPT tester. And even if its not perfectly accurate, all I was trying to achieve was to see a comparison between all of the panels. If the majority tested in the 200w+ range, then I can use that a baseline to see if there is any big variations or blatantly bad panels, ie the 106w panel
Was this how they based their advertisement?
I asked SanTan what an acceptable range would be for testing panels, and all he said was if they are between 33-35v VOC, then they should be fine. Well, all 58 of my panels tested atleast 33v, including my 1x that was at 62w, so clearly this is NOT an acceptable way to test solar panels....
They advertise they have been tested and have good output. So they are either not testing them, or their version of "good output" is wildly different from mine (or most DIYers I'm sure)
 
No, there is not a documented guarantee, but it does say on their listing "Panels have been tested and have good output.". Would you consider 106w to be "good"?


Yes, the tester I have is a true MPPT tester. And even if its not perfectly accurate, all I was trying to achieve was to see a comparison between all of the panels. If the majority tested in the 200w+ range, then I can use that a baseline to see if there is any big variations or blatantly bad panels, ie the 106w panel

They advertise they have been tested and have good output. So they are either not testing them, or their version of "good output" is wildly different from mine (or most DIYers I'm sure)
OK, maybe I need to back up. What is the amperage and the VOC on the back of your panels?
Measure your panels VOC in best sun at 90 degrees of your panel. Multiply that with your amperage. Result?
Now multiply that figure by 75 percent. This is where your used panels should set at, if not then they may be bad. But Before I call foul, I would hook them up to a actual solar controller and measure the actual wattage coming out of them. Not saying that your amazon meter is wrong but I would verify before i caused a stink. Meters have been known to be wrong.
 
OK, maybe I need to back up. What is the amperage and the VOC on the back of your panels?
Measure your panels VOC in best sun at 90 degrees of your panel. Multiply that with your amperage. Result?
Now multiply that figure by 75 percent. This is where your used panels should set at, if not then they may be bad. But Before I call foul, I would hook them up to a actual solar controller and measure the actual wattage coming out of them. Not saying that your amazon meter is wrong but I would verify before i caused a stink. Meters have been known to be wrong.
VOC spec is 37.6v, ISC is 8.27a

When using a multimeter, it shows VOC at 32.5 and my clamp meter shows 8.4a with the panel shorted (both MC4's connected.). This doesn't show results under LOAD, which is whats important! No load tests don't mean anything! Even the panel thats COMPLETELY rusted inside shows 32v VOC.

This same panel shows under load it goes down to 24.5v, and 6.6a for a measly 162w. Meanwhile with the multimeter, 32.5v X 8.4a, makes 273w X 0.75 = 204w.

If thats the case, and my Solar Panel Tester is 40w off, then the panels that tested at 230w should actually output 270w? 20W over STC? In 105* weather with some dirt on the panel?

I trust the solar panel tester more than I do a multimeter and a vague " 75% ".
 
Looks like SanTan Solar is taking the initiative and has offered to send me new ones. Im very impressed.

I have also offered to repalletize the panels that underperformed to return them, if they schedule a pickup.

I'll keep updates posted here.
 
Looks like SanTan Solar is taking the initiative and has offered to send me new ones. Im very impressed.

I have also offered to repalletize the panels that underperformed to return them, if they schedule a pickup.

I'll keep updates posted here.
Excellent
As far as this statement" I trust the solar panel tester more than I do a multimeter and a vague " 75% ".

Personally, I do not trust a multimeter or a panel tester for true results. I trust a solar controller with a load on to verify real world energy production. The statement that I made about the 75 percent was based on used panels that I have purchased checking the rated VOC with actual VOC with multimeter. 75 percent output is pretty normal for old panels.
 
I just got confirmation that SanTan is shipping me 8 more panels for free as replacements. I cant say enough good things, and cant wait to do future business with them!
 
When using a multimeter, it shows VOC at 32.5 and my clamp meter shows 8.4a with the panel shorted (both MC4's connected.). This doesn't show results under LOAD, which is whats important! No load tests don't mean anything! Even the panel thats COMPLETELY rusted inside shows 32v VOC.

A shorted output represent the panel under pretty much full load though. Imp and Isc are very close to one another.
 
Got an email confirmation today of a shipment arriving tomorrow. Very cool, and I'm super appreciative that they stepped up and are helping me out. Will post updates once I receive them
 
A shorted output represent the panel under pretty much full load though. Imp and Isc are very close to one another.
I wonder if I can somehow measure voltage when shorted as well. Its one thing to see 34VOC, and 8.4a ISC, but when shorted the voltage might fall significantly?
 
I wonder if I can somehow measure voltage when shorted as well. Its one thing to see 34VOC, and 8.4a ISC, but when shorted the voltage might fall significantly?
Would two multimeters work? One doing the amperage and one doing the voltage?
 
I wonder if I can somehow measure voltage when shorted as well. Its one thing to see 34VOC, and 8.4a ISC, but when shorted the voltage might fall significantly?

Your voltage will drop to zero at that point. Have a look at the MPP curve:

exp81.png

You can see that at MPP you have a voltage and current that result in maximum power. However if you look at Isc, it is very close to the current in the maximum power point.
 
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