How bad shipping could effect solar panel?

[ramiws]

Hi,

I have ordered 4 panels each are 60cells 1.5*1 meters. Together with around 50Kg of batteries and MPPT chargers. Unfortunately, they have put the heavy box on top of the middle of the solar panels and they have travelled over many countries via sea and road. So that 50Kg have been bouncing and flexing the panels all the way to me. Check attached picture to see how I got them. The panels package had clearly couple of "Do not stack" on them.
After further inspection, I noticed many and one broken cell module. I contacted seller and they offered to replace the panel with broken module and also the one on top ( under the heavy box). I told them all of them have signs and scratches as evidence that all of them got beaten up. I told them that I cannot see the cracks in other module as they are invisible, but they reduce the panel power and longevity. They said no scratches does not effect the functionality. I explained over and over it is not the scratches that I am concerned about, it is the module and cracks in them. I even sent them video about invisible damage caused by heavy pressure point.
What can I do to prove the damage to them? Is it possible to check each module individually?

Here is album of all the scratches:
https://photos.app.goo.gl/irQfC5ZQf3rRZsuG7

The video I sent them:

 

[gnubie]

If you can get hold of a thermal camera you should be able to see the temperature effects of the cracks with the panels connected to a load. You'll see above average temperature hot cells or even the cracks themselves if you have a high enough resolution (expensive) camera. There's quite a bit of info out there about detecting panel flaws with thermal cameras.

See this Google search

The scratches on the glass won't cause a problem but given there is an actual visibly cracked cell there you can be pretty sure there is damage there that isn't visible too.

 

[ramiws]

... given there is an actual visibly cracked cell there you can be pretty sure there is damage there that isn't visible too.

They said that visibly cracked cell is from manufacturing and not shipping.. But I doubt that manufacturer has so bad QA to let that huge crack pass...

I don't have thermal camera Is there any other way?

 

[HRTKD]

Hard to believe that they shipped it that way without some stiff barrier between the panels and the rest of the items. I would request a new panel. The rest of them are probably OK.

 

[GXMnow]

I would test the panels with an amp meter. A short circuit current test will show if the panels are all producing what they should. Just check all four at the same angle to the sun without a shadow. If the outputs all match, they are likely all okay. If one or two are lower than the others, then those are damaged. If you have the manufacturer's specifications, you should expect to get about 80% of the ISC rating if they are flat to the sun with a clear sky. The full ISC rating is in absolute perfect conditions. Even a small crack in just one cell could knock the current down a lot, so it should be obvious if there is internal damage.

 

[ramiws]

So if I short circuit current and then short circuit voltage test with multimeter. Does multiplying both values gives me power?

 

[gnubie]

Not really. The voltage you read will be Voc, ie when you are not drawing any power. The current you read will be Isc, short circuit current, not normally what you'd be doing either. You can get a rough idea of the panels wattage though, assuming the panel is receiving sufficient light to reach full power. If it's a mono panel multiply Voc x 0.8 and Isc by 0.95 and finally multiply those results. Voc x 0.8 x Isc x 0.95.

If you only want to gauge power from the panel as is, in existing non-optimal light rather than working out the paper rating of the panel this method will work just as well