Troubleshooting solar setup... or troubleshooting my troubleshooting!!

[CatNewBee]

Originally Posted by Captain Bill

Voc and Isc will definitely sort out the panels, but it will not sort out the setup as requested by the OP. None of his posts so far has shown that his controller is working properly, though I suspect it is because he was doing his testing early in the morning before the panels were producing sufficient voltage under load. The information I posted about what he should expect the panel side voltage to be if the MPPT controller is working properly was to evaluate the controller, not the panels.

the controller can easily be testd, mesure voltage and current on both sides, multiply input values ( V×I ) and compare to the product to the output values ( V×I ) or just read the values in your victron app. The difference should be less than 5% (95% efficiency).

If the controller breakes, usually there is either no output at all (damaged FET) or there is a problem with the voltage regulation. Victron has a microcontroller inside, that does a self-test on all crucial values, it will tell you when it is broken.

[basssears]

OK, since everyone has invested time and energy into trying to help me out on this I will wrap it up with the results of my latest testing. My conclusion is I have one, possibly two bad panels and that the other two are just, well, not very well made.

Test conditions were sunny day, hot (93F/33.8C degrees) at 44 degrees latitude. Started my testing as close to solar noon as I could (solar noon was 13:42) and all my tests were done in full sun (there were some cumulus clouds bouncing through every now and then but I waited them out and only tested in full sun). Panels were laid level, flat, not pointed or anything. Each panel was measured individually as a 50w, 12v nominal panel (Voc = 22.7w, Isc = 2.84a).

On the back of the panel it has Voc/Isc adjustments for temperature, I assume that is the temp of the surface of the panel not the air temp, correct? Don't have a heat gun here so don't know how hot the panels were getting.

As an attempt at a "control" subject I had my camper van out as well, with its 100 watt panel mounted flat on its roof and observed wattage on its Tracer MPPT at same time I was looking at the Victron app.

I measured Voc, Isc (using inline multimeter which seemed more accurate than my clamp on that was wigging out in the sun anyway... I know, crappy tools ), wattage from the individual panel, and wattage from the van setup at the same time (so same conditions).

Here are the results:


I also tested back and forth between the two controllers to rule out some sort of controller problem.

At 14:59 tested van panels to both controllers, Tracer = 75.6 watts Victron = 76w

At 15:07 tested panel #1 to both controllers, Tracer = 28 watts Victron = 23w

Conclusions??? My conclusions are:
* It's not the controller.
* Panel #2 is bad.
* Panel #4 is possibly bad, certainly not impressive.
* Panels #1 & #3 seem to be functioning... well, OK. But still only getting 40-60% of rated wattage while supposedly identical Renogy panels on the van are putting out 79-90% of rated wattage.

Maybe I drilled too many holes in the frames when I made them hinged or something about my folding setup screwed everything up.

At this point I haven't decided how to proceed. Despite how happy I've been with the Renogy on the van I think I'm done with them (haven't heard a peep in response to multiple support emails, although haven't called yet). Based on Maine Sail's recommendation I've been looking at Sunwize panels, they have a 65w 24v panel that would fit decently without having to be folding... I'm considering going to two of those, or possibly one of those and pairing panels #1 & #3 together for now and getting my 50% of output from them which would probably be equivalent to the Sunwize 65w if the Sunwize performed better.

Sunwize 65w:
https://www.sunwize.com/product/0186...-wp-f-c1d2-jb/

Aleko also has a 75w that would probably fit:
https://www.alekoproducts.com/ALEKO-...p75w24v-ap.htm

Harumph. Thanks for everyone's help and input, I at least feel like I tested as carefully as my tools and knowledge would allow and feel like I have at least come to some conclusion.

-- Bass

[thomm225]

Originally Posted by basssears

Maybe I drilled too many holes in the frames when I made them hinged or something about my folding setup screwed everything up.

-- Bass

Just a "small" piece of information left out can alter the whole troubleshooting scenario...……….

Which is why it's so hard for folks to troubleshoot second handed...………

[basssears]

Originally Posted by thomm225

Just a "small" piece of information left out can alter the whole troubleshooting scenario...……….

Which is why it's so hard for folks to troubleshoot second handed...………

OK, then how am I supposed to mount panels if I can't drill any holes in the frame (waaay waaay away from the actual panel itself, I didn't penetrate any sealant or anything)?


Did all the drilling just shake things loose? Here's how they turned out:

[thomm225]

Originally Posted by basssears

OK, then how am I supposed to mount panels if I can't drill any holes in the frame (waaay waaay away from the actual panel itself, I didn't penetrate any sealant or anything)?

Should be fine then...…...but if you took it in for repairs the tech would first check anything you did to the panels before beginning any troubleshooting electrically

[CatNewBee]

Originally Posted by basssears

OK, since everyone has invested time and energy into trying to help me out on this I will wrap it up with the results of my latest testing. My conclusion is I have one, possibly two bad panels and that the other two are just, well, not very well made.

Test conditions were sunny day, hot (93F/33.8C degrees) at 44 degrees latitude. Started my testing as close to solar noon as I could (solar noon was 13:42) and all my tests were done in full sun (there were some cumulus clouds bouncing through every now and then but I waited them out and only tested in full sun). Panels were laid level, flat, not pointed or anything. Each panel was measured individually as a 50w, 12v nominal panel (Voc = 22.7w, Isc = 2.84a).

On the back of the panel it has Voc/Isc adjustments for temperature, I assume that is the temp of the surface of the panel not the air temp, correct? Don't have a heat gun here so don't know how hot the panels were getting.

As an attempt at a "control" subject I had my camper van out as well, with its 100 watt panel mounted flat on its roof and observed wattage on its Tracer MPPT at same time I was looking at the Victron app.

I measured Voc, Isc (using inline multimeter which seemed more accurate than my clamp on that was wigging out in the sun anyway... I know, crappy tools ), wattage from the individual panel, and wattage from the van setup at the same time (so same conditions).

Here are the results:


I also tested back and forth between the two controllers to rule out some sort of controller problem.

At 14:59 tested van panels to both controllers, Tracer = 75.6 watts Victron = 76w

At 15:07 tested panel #1 to both controllers, Tracer = 28 watts Victron = 23w

Conclusions??? My conclusions are:
* It's not the controller.
* Panel #2 is bad.
* Panel #4 is possibly bad, certainly not impressive.
* Panels #1 & #3 seem to be functioning... well, OK. But still only getting 40-60% of rated wattage while supposedly identical Renogy panels on the van are putting out 79-90% of rated wattage.

Maybe I drilled too many holes in the frames when I made them hinged or something about my folding setup screwed everything up.

At this point I haven't decided how to proceed. Despite how happy I've been with the Renogy on the van I think I'm done with them (haven't heard a peep in response to multiple support emails, although haven't called yet). Based on Maine Sail's recommendation I've been looking at Sunwize panels, they have a 65w 24v panel that would fit decently without having to be folding... I'm considering going to two of those, or possibly one of those and pairing panels #1 & #3 together for now and getting my 50% of output from them which would probably be equivalent to the Sunwize 65w if the Sunwize performed better.

Sunwize 65w:
https://www.sunwize.com/product/0186...-wp-f-c1d2-jb/

Aleko also has a 75w that would probably fit:
https://www.alekoproducts.com/ALEKO-...p75w24v-ap.htm

Harumph. Thanks for everyone's help and input, I at least feel like I tested as carefully as my tools and knowledge would allow and feel like I have at least come to some conclusion.

-- Bass

I would say panel 1,3 and 4 are ok, Isc is whithin the specs, panel 2 is dead, possibly a dead cell / hotspot.

[noelex 77]

Panel 2 is obviously defective, but the other results do not fit in. You are recording a higher Isc than the specifications for three of the panels. This is very unlikely and I think there must be something wrong with this measurement. The Voc is temperature dependent. At working temperature the Voc will be slightly lower than the specifications so your results for all panels is within the normal range.

The wattage results with two different controllers show all 4 panels are putting out way less than they should.

It would be sensible to repeat the Isc measurement with another multimeter. The testing results do not make sense. Voc and and Isc are not the same as the measurements with the controller which is at Vmp and Imp, but they should correlate well.

I think it is likely that all 4 panels are defective and the Isc measurements are wrong. However, the Isc test is a simple and normally reliable test of the solar panels’ ability to deliver current. I am very suspicious of your readings because the results are better than they should be even for new perfect panels (which suggests the data is incorrect), but it would be a shame to ditch the panels as defective with such conflicting data.

It is also not common for rigid panels to become defective. They are normally very reliable. The holes you have drilled should not affect the panel. Problems with wiring or defective solar controllers is a much a more frequent cause of issues so it would be nice to see all the data agreeing before concluding a rare (all 4 rigid panels panels failing) fault is too blame, although this seems the most likely conclusion.

It is a pity when you have been very thorough, and done all the correct tests, to be left without a sensible conclusion, but I think repeating the Isc test with a different multimeter is the next logical step.

[thomm225]

As a final test, hook up Panel Number 2 straight to a battery (no controller) that has been drained down to about 12 volts or so, have a beer and monitor it. (Btw, is the connection right at the panel good? not from it's wires but right at the diodes etc in the small J Box on the back. If there are screws, are they tight? And did you put any splices in the wires of number 2 that could be weak, partially open? I did see a wire nut in one of your pictures. If so hook good/complete wires directly to J box terminals on the back of the panel......as in pulling the cover off the box and hooking up before testing)

See if it will charge the battery up to 14 volts in a couple hours. One panel, one battery, wires. Don't let it charge over 14.2 or so though and hurt the battery

I let my batteries drain down to 12.4 volts from 13.7 volts during the day yesterday with VHF, Depth, and GPS on and my big panel (65 Watt) turn down (facing cockpit)

I did this because I was resetting my panel to a better place anyway. After work and after panel was moved, I check voltage no load. It was about 18 volts at 5pm. Hooked it up and it was close to battery voltage about 12.4. After one beer, it was at 12.6.

So I knew it was charging the batteries back up but then thought of my "current" friends on CF so I moved the leads on my $10.00 meter for current check. Removed the positive lead from the controller of the panel and checked the current holding everything in my fingers and the other probe on the controller screw and it was almost 1 amp which I was happy with since either the boom, tiller, or my head was blocking the panel at 5 pm

All this took 10 minutes. Hooked everything backup and watch the panel charge the battery to 13.1 before I left. Max current readings on the panel plate were around 3 amps so near 1 amp @ 5pm was good ………. but as before the voltage was telling me it was charging normally. Amp check was for fun

[thomm225]

A bad connection, loose/corroded connection, or frayed wire etc could explain why you have good VOC and not so good current on #2

As was mentioned above concerning rigid panels, my panels (rigid) have been beaten up. The main one isn't mounted but sits/lays on my aft lazarette and gets bounced around every time I open it for fuel etc for my outboard and the panel it still working great but I've had to redo wiring connections repeatedly

I also sit on it to get to steer with my outboard when docking and have sort of stood on it......

[basssears]

Originally Posted by noelex 77

The wattage results with two different controllers show all 4 panels are putting out way less than they should.

Agreed! I realize reading back I sound like a total newb here, but I do have successful solar setups on a van and a small trailer sailor. I'm not expecting 50 watts out of my 50 watt panels, I know that's unrealistic, but I don't think in mid summer 80% of rated is unrealistic.

Originally Posted by noelex 77

It would be sensible to repeat the Isc measurement with another multimeter. The testing results do not make sense. Voc and and Isc are not the same as the measurements with the controller which is at Vmp and Imp, but they should correlate well.

I will try as you suggest. I found the clamp meter was giving me very variable results, wavering up and down (earth's field and all that) so used my simpler Etekcity MeasureUp inline for current readings:
https://www.amazon.com/Etekcity-MSR-.../dp/B01N9QW620

But I will redo the tests with the clamp meter (and using the inline meter again) to double check.

Thanks.

[basssears]

Originally Posted by thomm225

As a final test, hook up Panel Number 2 straight to a battery (no controller) that has been drained down to about 12 volts or so, have a beer and monitor it.

I will try, as you suggest, going straight to the J box. The wire nuts you saw are because these are all temporary tests right now as I removed this whole setup from the boat to troubleshoot... but I guess always a possibility something within the MC4 connector is bad or something on panel #2.

My problem with this style of testing for the other panels is it only shows to me, unless I guess I do a bunch of the math, whether a panel is putting out any charge at all, not how much. If I hook up panel #3 (which put out 20 watts yesterday in my tests) to a battery it will eventually charge it up, but I'm still getting only 40% of rated... if I'm only going to get 20 watts I might as well use my nice folding 27 watt Goal Zero panel instead of this big heavy framed 50w panel...

[thomm225]

Originally Posted by basssears

I will try, as you suggest, going straight to the J box. The wire nuts you saw are because these are all temporary tests right now as I removed this whole setup from the boat to troubleshoot... but I guess always a possibility something within the MC4 connector is bad or something on panel #2.

My problem with this style of testing for the other panels is it only shows to me, unless I guess I do a bunch of the math, whether a panel is putting out any charge at all, not how much. If I hook up panel #3 (which put out 20 watts yesterday in my tests) to a battery it will eventually charge it up, but I'm still getting only 40% of rated... if I'm only going to get 20 watts I might as well use my nice folding 27 watt Goal Zero panel instead of this big heavy framed 50w panel...

In my experience, it's rare that things (electronic or electrical) are partially broken...........like only getting 20 watts out of a 50 watt panel.

It's usually best to troubleshoot along the lines of something is totally broken or down

When you find a problem, it will usually take care of the partial problems you are seeing.

It's rare that you really need all the elaborate tests as have been described in this thread to troubleshoot your average electrical problem

[thomm225]

Also, if you do another one of those elaborate tests, don't forget to move the wires around and tap on the frame while testing. Look for a change

I troubleshoot these with voltage alone as I said before. Many time at anchor if my voltage isn't clicking back up as the sun rises I know there's a problem.

On my system it's usually an external wire because of it's location, but has also been the controller

[CatNewBee]

it is not un

Originally Posted by thomm225

In my experience, it's rare that things (electronic or electrical) are partially broken...........like only getting 20 watts out of a 50 watt panel.

It's usually best to troubleshoot along the lines of something is totally broken or down

When you find a problem, it will usually take care of the partial problems you are seeing.

It's rare that you really need all the elaborate tests as have been described in this thread to troubleshoot your average electrical problem

it is not uncommon with solar panels, cells are huge and tiny fractures can cut part of the area of a cell, the remaining part still outputs some current. Cells are in series, so if one cell gets weak, the whole string is limited to the current of that cell. Also hotspots due to partial shading and resulting reverse currents can fry a cell.

[thomm225]

Originally Posted by basssears

My problem with this style of testing for the other panels is it only shows to me, unless I guess I do a bunch of the math, whether a panel is putting out any charge at all, not how much. If I hook up panel #3 (which put out 20 watts yesterday in my tests) to a battery it will eventually charge it up, but I'm still getting only 40% of rated... if I'm only going to get 20 watts I might as well use my nice folding 27 watt Goal Zero panel instead of this big heavy framed 50w panel...

There's no math involved. I was just giving you a simple test to use, but I'm used to troubleshooting with voltage alone.

Once again, look for a problem, not a weakness or partial problem. Does this panel work on not. Yes or no and go to the next.

Also, it would be very odd if all 4 of the panels were bad. I've seen one time in 40 years where two circuit cards failed simultaneously