China no brand panels - overheating damage?

Bones

Hi all,

I noticed this morning that the voltage display on my charge controller was swinging rapidly between 13.9 and 15.1 volts.  I went outside to have a look at the panels in case there was some foliage blowing around and casting some shade ( my panels are mounted on an angled frame about 15cm off the ground, so I have to regularly clean around the panels to prevent plants growing up around them).  There was nothing casting any shade but a little pollen dust on the surface so I started wiping it off, and noticed a small brown spot on a piece of the tab wire between two cells, this spot was very hot to the touch, and I noticed that the whole cell was hot compared to the other cells.  I disconnected this panel and the voltage display on my cc stabilised at 14.1v (where it should be). 

I turned the panel over and found that the backing around that cell was bulging a little. 
I then looked at the other panel and found no brown spots, but running my hand over the panel, I found two cells that were also quite hot to the touch. 

The Vsc of the two panels separately was 20.5 so voltage wise they are both acting the same.
I was unable to test the Isc as my multimeter is broken ( maybe the fuse), so I instead connected each in turn to the cc, and the display showed 7.1 amps from the *good* panel, and 4 amps from the panel with the scorched tab wire. Both panels are rated at 8amp max.

I have now covered and disconnected the *burnt* panel and left the other panel connected, as i'm concerned that the panel with the burnt tab could cause a fire. Could anyone shed any light on the best course of action with this panel?

Also, is it normal for some cells in a panel to feel considerably hotter to the touch than others, or is this a sign that my other panel (with no visible marks) is also on it's way out?

Thanks for any comments or suggestions, I really have no idea what I should do about this short term.

Chris

 

BB.

You have a bad electrical connection or bad cell.

The panel is bad and not repairable. If you can get it replaced under warranty, it is time to do it.

Why it failed, I can only guess. But manufacturing defect or handling damage (hit from behind thru soft backing) would be high on the list.

-Bill

Bones

Thanks Bill, 

I think it's unlikely i'll get a replacement - the panels are I think from a company called Eco-worthy.  I checked their website and although it says the panels come with a five year warranty, when I checked the T&C I found this paragraph:

"Warranty Disclaimer
This site and the materials and products on this site are provided "as is" and without warranties of any kind, whether express or implied. To the fullest extent permissible pursuant to applicable law, Eco-worthy disclaims all warranties, express or implied, including, but not limited to, implied warranties of merchantability and fitness for a particular purpose and non-infringement. Eco-worthy does not represent or warrant that the functions contained in the site will be uninterrupted or error-free, that the defects will be corrected, or that this site or the server that makes the site available are free of viruses or other harmful components. Eco-worthy does not make any warrantees or representations regarding the use of the materials in this site in terms of their correctness, accuracy, adequacy, usefulness, timeliness, reliability or otherwise. Some states do not permit limitations or exclusions on warranties, so the above limitations may not apply to you."

Seems pretty conclusive.

I've emailed them anyway - worth a shot I guess!

If I hear nothing back i'm quite tempted to carefully cut away the backing around the cell and solder a new tabwire as a bridge over the burnt area as it seems i don't have much to lose

With regards to the other panel that has some cells that are quite a bit warmer than others - would you consider this a sign that there are also bad connections/cells in this panel?  I have to go away for a couple of weeks in May, and don't feel so good about leaving a faulty panel connected and unnattended for a period of time.

Thanks for your help, 

Chris

Estragon

The warranty disclaimer is likely for the website itself.  I'd press on the warranty, not just give up because they don't get back to you right away.  I'd also try to quantify "quite a bit warmer" with a temp meter

Bones

Ahh, I see.  I have had a reply from the company "eco-worthy".  They have offered me a "good price" on new panels instead of warranty replacement.  I have asked them for more details on their offer as I recognise that a warranty claim along with shipping costs could in itself be lengthly and costly.  It all depends on how far they are willing to go price wise to avoid negative feedback I guess.  Especially if I can repair what I suspect to be a cold solder joint on the faulty panel.  I'll try to borrow an infrared thermometer from a friend tomorrow and quantify quite a bit warmer