Solar panel testing. Good results. Mostly...

Oh boy, this has come a long way. I've setup the JNGE charge controller again and connected the tractor battery. All panels are now out in the driveway. It looks like "Andy's Solar Panel Junk Yard". But hey, we are now getting good results. At the panels with open junction boxes, we are measuring some voltage. The results are... unexpected.
I have now labelled all panels as per their mpp voltage and current so I can group them together. This should work on the roof as well, right?
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[@NathanKrick]

Andy, your lawn tractor has wheels, you can move it out to the driveway next to where you are testing and then 15m will be more than long enough.

[@OffGridGarageAustralia]

Don't destroy everything I said in the video. #15mistooshort 😂

[@edc1569]

Must get myself another case of those solar panel directional calibrators.

[@OffGridGarageAustralia]

Hahaha, great expression. I will use this from now on!

[@Nobody_Famous]

@@OffGridGarageAustralia they might even be tax deductible if used in a video

[@andrewradford3953]

Picked up a case of Oettinger Pils this afternoon and said I didn't want the receipt because I couldn't claim it. Was previously working on my off grid system and could have used a professional calibration device. Maybe several if they fall off the panels..

[@OffGridGarageAustralia]

@@andrewradford3953 Man, you should have asked for help with that. Also make sure the cans are empty before you use them on the panels 😊 If you need any help with that in the future, let me know 😂

[@andrewradford3953]

@@OffGridGarageAustralia Next time you are heading up this way we should calibrate a few of my tilt arrays! I'll email you my mobile to contact me. Last time I missed your email. :(

[@TBL_stevennelson]

Never use a full can. Take one for the team and drink a beer at the beginning of all testing. For science

[@defjamsgreen]

YOU HAVE BROUGHT THE BEST OUT OF FAIR TO BAD PV MODUELS BY GOING ABOVE AND BEYOND ALL OTHER MEASURES IN FINDING THE ONES THAT QUALIFIES BEST REDULTS IN VOLTAGES AND AMPS . KEEP UP AND NEVER GIVE UP . MAY THE SOLAR BE WITH YOU .

[@adhanndungu7622]

Hello adhan from Kenya Africa aim Soo happy for your instructions

[@OffGridGarageAustralia]

Thank you and hello to Kenya!

[@largepimping]

Andy, I'm a native English speaker, and to me, you nailed saying "subscription" at the end. So I was totally confused when you stopped yourself!

[@OffGridGarageAustralia]

It's a hard word for me 😊

[@laurinpestes5569]

Makes me want to prune back those trees. Though your heat makes the shade look nice, too.

[@andrewradford3953]

I volunteered to lend Andy my solar charged electric chainsaw.. But the trees are too valuable in Summer.

[@TBL_stevennelson]

Is still cold here in Canada. I think your on the right track. Used panels are difficult to use because you never know what type of life they have had. 3 panels could have been in shade most of its life and the rest got full sun.

[@alanhollister9122]

But all in all, I think you’re doing the right thing. And it’s about the only way you can do it with used panels. Take the best and use em tell they die!!

[@OffGridGarageAustralia]

Thanks Alan. Yeah, it seems like most of them are OK to use.

[@1972prem]

Just recently discovered your channel Andy. Live every video. Now going back and watching older ones because I need more 😁

[@edwardvanhazendonk]

Great you have at least a 1000Wp which is working, thanks for sharing and have a nice beer!

[@OffGridGarageAustralia]

You bet! 🍺

[@thomasmoore4576]

Nice job testing how fun with the rest of them and don't forget your beer in a cooler so they're cool and cold 🥶

[@vickipps6821]

If I was there Andy I would definitely come and give you a hand but I live in South Africa you have a great channel I enjoy watching very informative when I wS working I did DC Power for 5 years most of the time doing solar 👍

[@OffGridGarageAustralia]

Thanks for watching Vic and all the best to SA. Stay safe!

[@zjzozn]

Brilliant ….. a beer at 10am 😂👍🥸

[@OffGridGarageAustralia]

Everything after 9am is fine!

[@mjpbase1]

Australians and their beer. Quite the love affair. 🍺 😀

[@OffGridGarageAustralia]

I'm not Australian though 🧐

[@mjpbase1]

@@OffGridGarageAustralia yes, Europeans like their beer too. Australians are almost European that way. I am enjoying your videos.

[@aaronwalker1507]

@@OffGridGarageAustralia you've been living here long enough

[@petercamusojr1545]

Snail trails are micro cracks in the diode/cell. Damaged goods. Micro cracks will go bad after awhile. Visualize inspections for cracks, discolorations, crinkled surface and burn marks. Inspect front and back (white side) of panel.

[@DavidLouthan]

Lmao I will come help roof em up! U too funny my good man! Cheers and sunny days 🌞

[@OffGridGarageAustralia]

Thanks David 🍺

[@DavidLouthan]

@@OffGridGarageAustralia 🍻

[@jasondevine6014]

Awesome to see some progress. This has been bugging me for some reason... As you say should be the simple part. Please fix your BMS you are only 1 controller failure away from wrecking your batteries.

[@OffGridGarageAustralia]

Man, I constantly monitor my battery through the VRM now. I can easily live without a BMS altogether. But, yeah, thanks for the reminder...

[@ddthames]

I think you are making more of the heat and being tired so people will feel sorry and send extra beer money :) Great job.

[@OffGridGarageAustralia]

WHAAAAT??? I would never do that. You need a fresh can for every test. That is the rule!

[@walterweese2527]

@@OffGridGarageAustralia lol that's why you'll check east- and west-side again and again and.... I wish you much fun and a healthy liver. hand walter. Proschd! ..oneh gähd noh, oneh gähd noh neyh.. rofl

[@goofykl9]

looking forward to the next one

[@libertyauto]

Thank you for sharing your testing. This mystery was troubling me like crazy.

[@maleiot_83]

You are doing the Solar work so enthusiastically...i like that! Greetz from Austria! I think the bypass diodes only turns active, in case of shading....

[@OffGridGarageAustralia]

Thank you and all the best to Austria!

[@wayne8113]

Thanks Andy

[@cheetahkid]

At least you got my advice there, good. (I understand you are not throwing bad one out but make useful addition)

[@petercamusojr1545]

Chasing the sun, I did that trying to figure out why I only got 70 watts from my 100 watt panels. I think your closing in on the root cause of your low power. Good job.

[@OffGridGarageAustralia]

Thanks Peter. And the angle in winter. Even down here, the sun now comes from a bad angle on my roof. That as well makes a big difference.

[@andre495]

Hi Andy, About to the problems (also in your earlier video's): you are charging at 54.4 Volt, I think that is a bit low in regard to the chemical properties of LiFePo4. Try charging at 54.8 V! This is also why the panels work good with your irrigationpump. Thanks a lot for the video's, we are learning with you !! Kind regards, André from The Netherlands.

[@chuxxsss]

Morning Andy, loving the multimeter action.

[@OffGridGarageAustralia]

Thanks 👍

[@chuxxsss]

@@OffGridGarageAustralia It must be my German ancestors, which make me think the same Andy. I need a multimeter like your. I wonder if they oscillate the DC so they can use the clamp part of the meter.

[@seymourpro6097]

When you test a panel try to also test a known good panel as a control. If your known 100w panel reads 95w then you know that the sunlight is 5% down so the test panel will indicate 5% down. This accounts for variation in sun intensity and shading over a testing session.

[@georgev.]

Congratulations Andy, yeah some of the 180W panels are now junk 90W only. Well still 50% power but you would need more Charge controllers to get the energy and sum up to your battery and don''t penalize the power output of the rest.

[@OffGridGarageAustralia]

I thought about getting a cheap MPPT (or taking the JENDG or what its called) for these panels and just use them for bulk charging. Letting the Victrons do all the fine work at the upper limit of the battery. A future project 😊

[@Decouperotative]

...stay charged , stay safe, stay shadeless..👍

[@BrazzaB1]

Hi Andy. The cracked panels are usually from overheating, usually from shading. Same can be said for the bypass diodes.

[@OffGridGarageAustralia]

Yeah, not sure, never had a faulty diode. These are rated for 15A but max current of these panels is only 5A. So I cannot see how this can break them. Their operation temperature goes to 115°C, so...

[@kerryb2689]

I THINK for panels in series the current will be limited by the panel with the least current, and for panels in parallel, the one with the lowest voltage will mess up your mppt tracking voltage. SO it would be best to match as close as possible both voltage and current of the strings. I wonder if you could use a separate mppt controller for each matched series string - especially on the sunny side vs the shaded side. Let the controllers do the matching on the load side. ugh I never dreamed that old degraded panels would produce lower voltage at mppt power. At least you're finally making some progress.

[@OffGridGarageAustralia]

That's correct, in a series connection, the weakest panel pulls down your whole string. I have now matched them as per power and current so hopefully that makes a bit of difference. A charge controller for each string? I have a video for that: kzbin.info/www/bejne/rp_Xqa2vos-frq8

[@kerryb2689]

@@OffGridGarageAustralia I just watched that video. That's exactly what I am saying. Given the differences in your used panels, I think 1 charge controller for each matched string makes more sense. If all the panels were matched then maybe you could connect the strings together, but you're also dealing with the shading issue. I'm learning and figuring this out with you from your videos and hadn't thought about it before. My experience with solar consists of 3 suntech panels in series running a grundfos 6sqf pump to water livestock. I know 1 panel didn't cut it on a cloudy day, 2 panels was better, 3 panels is best....even though one of my panels is partly shaded by the cattle panel that keeps the cows out. My biggest problem is the well only produces 2 gallons per minute and there's not enough sunlight in a day to keep up with 70 cows on hot days. The solution I finally settled on was to buy a 900 watt generator from harbor freight (tailgator $125) and take it up in the evening when the water gets low. It's a 2 cycle engine and runs about 5 hours on 1 gallon of gas. What I really need is a battery with a way to limit current to about 150 watts without the device reducing voltage or consuming power itself (buck converter). Batteries are expensive, (especially enough to get to the 36v the pump requires) then you need the expensive controller for charging.

[@guy7gsa]

Oktoberfest at Andy’s house this year.

[@OffGridGarageAustralia]

What a great idea!🍺

[@lyfandeth]

Well, cut up one panel and use it to donate good replacement cells to the other bad panels. They can be repaired by swapping out cells, just be sure to waterproof the repaired panels.

[@MrSummitville]

Don't they pull a vacuum at the factory ?

[@cyberplebs6577]

Wenn Australien nicht so weit weg wäre, würde ich kommen. Gruß aus Berlin

[@OffGridGarageAustralia]

Die lassen hier keinen auf die Insel im Moment. Bis 2024 ist hier alles dicht. Unterstuetze mich virtuell! 💪

[@guywhoknows]

As the panels warm up they will make less power. Used panels are a gamble. Got mine on a cloudy wet day. Even picked up one marked faulty. Quick inspection and the tabs were not making contact... Quick fix :) My 10 amp meter was having a bad day with 18.23amps today. I've two 16 amp strings. I have to turn one off around peak time due to the controller losing control. Can't wait for a good day to test them But they seem fine, diodes are all working. In The frost the other day It looked like I had one hot spot on two of the panels. Well not -2..

[@mannyfragoza9652]

i bought a Renogy 100 Watt flex panel, only had about a year and a half and in that time I only used it a hand full of times, and im lucky to get 60 watts. i have 2 other 100 watts Chinese panels that give me 100Watts plus. Solar panels are funny you either get lucky and buy a good one or its crap. I like using the flex panels because i can move it around with easy where i can catch the sun when it tries to hide from me.

[@TheRoemer1]

Would totally come & help... but hard to get to you ;-) cheers from Switzerland

[@OffGridGarageAustralia]

Appreciate that!

[@NaughtyGoatFarm]

Hey Andy. I am happy to give you a hand this weekend to lift panels onto the roof. I also have a young fit backpackers staying with me who can also help.

[@OffGridGarageAustralia]

Thank you very much for your offer. The video is already over a week old, so all work is done. I'm far too impatient... Next time. Thanks again.

[@henvan8737]

The snail trail and micro cracking appears to be a bigger problem with the older 72 cell solar panels. Here is Melbourne we are seeing the same defects. I have one location where the micro cracking has developed into Hot Spots where a string of panels is feeding power into the cracked areas causing heating. A few panels have over heated so badly causing the front glass to break. This then leads to moisture getting in which causes an even hotter hot spot and potential fire. My advice is don't purchase any more used 72 cell panels.

[@OffGridGarageAustralia]

I have to check panels better before I buy. I will soon have the tester and know now what to look for from the outside. Yeah, the 60cells panels seem to perform a lot better.

[@TBL_stevennelson]

I just got a new panel that gives me 7 amps with clouds and shades I'm happy about it but I need to install them in the future after I get a few more. I just hope I don't run into any problems

[@OffGridGarageAustralia]

New panels should be fine.

[@rw-xf4cb]

turn those

[@electrodacus]

Yes at 11:500 that is a cracked cell and the reason this panel performs less as basically 24 cells out of total 72 cells are disabled by that (assuming is the only damaged cell). There was some mechanical damage maybe a stone or hit from the back. There is nothing wrong with the diodes as those will have a much more visible type of fault since they almost always fail as a short circuit. The cracked cell will act as a smaller cell so same voltage just lower current. Just curious how those cells got cracked as I have never seen any cracked cells on any of my panels and we get here large temperature delta -40C to +40C and hails (ice balls up to 1cm diameter). My best guess is that panels were damaged during install or uninstall.

[@OffGridGarageAustralia]

Thank you. There is no mechanical damage to the panels. It seems it's short on the cells, like a spark jumped from one wire to another and so on. Some of the panels with such 'bad cells' still have full power and performance, so I'm not sure what exactly that is and how it affects the panel in general. I guess it was a quality problem during production and over time these cells failed.

[@electrodacus]

@@OffGridGarageAustralia PV cells are basically made of glass and while they are thin and relatively flexible glass is glass and glass can break. Best guess is that when they were staked they may have slide and touch the corner of another panel thus cracking a cell. The cracked cells is super common on those semi flexible panels that some people install on top of cars. Is usually less than a year before most cells have microcracks and panel performance significantly drops. I just have not seen cracked cells on panels made of glass and aluminium frame. It is also important how the crack is as a horizontal crack will have almost no effect is like splitting a cell in two tho they will add up and perform the same but vertical cracks will just disable part of the cell completely as there are no more electrical connections to the main busbars.

[@realvanman1]

I wonder if measuring the short circuit current and the open circuit voltage and comparing them to the spec would be a good way to determine the relative health? You could have a switch with the connectors on it and provisions for a voltmeter and ammeter. Hook it up, take the voltage reading, then close the switch and take the current reading.

[@OffGridGarageAustralia]

That would not be sufficient as it does not show how the panel performs. It can only be measured in the maximum power point.

[@dickthompson8018]

Would the new meter you did a video on before be quicker or more accurate for this type of testing? I bet you’ll try it and let us know when you get it. If it does work out well, then used panels could be tested before buying them at the seller location??? Thanks as always for the great videos!

[@OffGridGarageAustralia]

Thanks Dick. Yeah, that's the intention of that tester, take it and test the panels before buying.

[@teardowndan5364]

Time to climb some tree and lop the tops off :)

[@OffGridGarageAustralia]

Nope, not gonna happen. 100+ years old trees won't be touched for that purpose. Only shade in winter, no prob in summer.

[@felaxchow207]

I maybe taking a bit of a stab in the dark with this. My best guess is that the defects one or more modules causing some sort of an impedance mismatch causing the MPPT controller not being able track properly to get the optimum power out of the string. The individual module that is hooked up on its own MPPT controller and even with the defect/damage would affect the output on just that one module; maybe the output is lower than specs, but it still has some usable output power regardless and not taking the whole string along with it. I wonder if you parallel those "bad" modules together on the JNGE charge controller to see if they will track and give you a better output or not? The challenge is finding a way to reliably test used solar modules in a quick and expeditious manner without wasting time with the person who is selling them to you and not get "sunburned" at the same time. Looking forward when you get the module tester and seeing the results on the questionable panels that you already tested and pointing to the preliminary results of being faulty. I myself have several free abused modules, hooked them up on individual microinverters and they work fine on their own; just tinkering around and they're producing enough free energy to justify them to be laying there on the sunny side of the storage shed.

[@OffGridGarageAustralia]

Yeah, it's hard to tell. Most modules work just fine individually with the controller. Now, I have put them all in 'classes' and will create new strings as per the specs I measured under ATC (Andy's Test Conditions). That's probably the best I can do.

[@felaxchow207]

@@OffGridGarageAustralia At least it was sorted and matched on the ground vs on the roof.

[@sjdtmv]

Andy just as a test, cut off the MC4 connectors and wire directly, I have had badly oxided MC4 connectors on 2nd hand panels, MC4 connectors being not gold plated, sometimes it's like having a bad battery connection on a car

[@OffGridGarageAustralia]

I sprayed some of them with WD40 and they are better than brand new one. Gets rid of all the dirt and corrosion.

[@michaelbouckley4455]

Some MC4 are plain copper, others Silver plated.

[@5885ronny]

Hallo super Video danke dafür 🤗 ich habe jetzt auch eine Größe Speicher Anlage 24 volt Lifepo4 Akkus 27 kWh 🤗👌 LG danke

[@jjromba]

Hoffe du hast schon das Oettinger Ausricht-Profiwerkzeug patentieren lassen 😆

[@OffGridGarageAustralia]

Aber klar. Jede Messung benoetigt aber eine neues Werkzeug...

[@jjromba]

@@OffGridGarageAustralia you need more beer donations

[@landonferguson7282]

Can you introduce us to your pups? 🐕

[@tabineshhtc]

Wow

[@olayinkaolatunde3028]

What clamp meter is best to buy between these options please? UT210C UT210D UT210E UT204+ Thanks

[@martinmuller1145]

In a former Video about your Battery you were worried about the shorten mechanical relais of the BMS. Did you receive a new one from China? Or did i miss a new test in a new Video?

[@OffGridGarageAustralia]

I got a new one from them and have not installed it yet. I totally forgot about it. Thanks for the reminder 🤦‍♂️

[@peterpetersen6024]

It's nearly impossible to compare the panels with constantly changing sunlight. Your eyes and the camera compensate most of the changes. You could either buy something like a "lumen-meter" and try to standardize your amp and volt readings mathematically to the actual sunlight. Or just buy a 1000W LED spotlight (round about 50$). You will not get the peak readings, but something where you can compare the panels under controlled (rectangular angle, same distance panel to lightsource, constant light without clouds, etc.) conditions. And it's much easier in terms of running around and length of the cable. ;-) Than you can test open voltage, short current, mppt best point, in-panel-string-voltages, etc. really quickly for all panels. Put them in a table and ask the swarm intelligence of YT what to do with this data. :-D ;-) And remember: The bypass diodes are only needed, if an in-panel string has a failure or is shaded. In your video you shaded the cells of the in-panel string, where the diode was faulty and the amps dropped dramatically. Would be interesting to see what happens with a working diode.

[@OffGridGarageAustralia]

Thanks Peter, that's all a lot of effort. I have unsoldered the diode and it is working perfectly fine. Tested until 30V and works both ways as intended. This is not caused by the diodes, I'm afraid.

[@wildez007]

The degradation is in the cables, if you take your worst panel and upgrade the cable coming out of the junction box, you should see full amps 👍

[@OffGridGarageAustralia]

How can a cable degrade?

[@wildez007]

@@OffGridGarageAustralia oxidation ……..if you find greenish or white powdery appearance at the connectors on the wire side this is an indication of cable degradation

[@wildez007]

Oxidation hinders the electrical conductivity of copper wire.

[@wildez007]

You can also damage connectors when disconnecting without removing load, as the plasma arc will burn the inside of the connectors, thus reducing conductivity, so it is better to remove any load before uncoupling your connectors.

[@corruption902]

Definitely worth soldering on a new cable pair to a panel to test. If it brings the panels back into spec, it'll be a relatively cheap fix. If it doesn't work, it'll be a minor inconvenience but will be good video content.

[@Josemanc]

On my way...

[@OffGridGarageAustralia]

🍺🍺🍺🍺

[@DIYwithBatteries]

I didn't even seen a constant voltage Or current on meter. I think there was a wrong with the selector thing or may be the probes. 🧐

[@hwesson75]

The readings were moving around like that because of the mppt charge controller adjusting it's tracking trying to find the best adjustment for the freshly plugged in panels being tested.

[@ChetCheng]

Get me a plane ticket for 2 and I'll come over there

[@OffGridGarageAustralia]

They have closed the island and don't let anyone in until 2024 :D

[@ChetCheng]

@@OffGridGarageAustralia I can wait 😂

[@alanhollister9122]

I may be wrong but, I’m under the understanding that panels degrade over years of use. And if they have been left running in open current they degrade even faster. They can look ok but still be degraded. That’s my understanding anyhow but I could be wrong

[@jmaus2k]

Sunlight degrades them at about 0.5% per year similar to how paint in the sun fades. Rough handling by pushing on the back of the panel can crack cells, which is probably the main reason many of these old panels are not performing. The tedlar on the back can also be scratched which would allow moisture and fogging.

[@mechcraft]

How about using a thermal camera while testing panels sir? Thank you for your videos.

[@OffGridGarageAustralia]

I haven't got one.

[@FutureSystem738]

@@OffGridGarageAustralia And they’re expensive!”

[@SigmaWorksSW3D]

Nice ;)

[@OffGridGarageAustralia]

Thanks 😋

[@francisboudreaux3880]

Half power is better then no extra power

[@OffGridGarageAustralia]

Every Watt counts, right?!

[@mjp0815]

You need standard test method using an artificial light source.

[@OffGridGarageAustralia]

I have ATC. *A*ndy's *T*est *C*onditions

[@mjp0815]

@@OffGridGarageAustralia ... ATC is giving your legs a good workout! Keeps you young and us entertained! Keep it up Andy! 🍺🍻🍺

[@glenndeveigne1732]

You might be better off to run AC coupling to run your shed during the day and then you can run your battery pack at night, best of both worlds, research this and you will understand what I am talking about

[@OffGridGarageAustralia]

Why should I do that. that makes no sense at all.

[@mikeKirwin]

Andy, if you don't find a solution to the differing output of your various panels, here's something else to consider. Apparently you can test for damage on PV cells that can't be seen by the human eye with Infra Red light: "IR Pictures can be made easy and cheap with a dark room, a suitable DC power source to reverse power the solar module (bypass any diodes) and an old Sony F717 or Sony F828 with s small magnet to put it into "nightshot" mode." The info came from here: kzbin.info/www/bejne/bIiqfK1oqLqUZtk And here: endless-sphere.com/forums/viewtopic.php?f=6&t=94721&start=250

[@VIAMediaGroup]

I hope you wouldn't mind helping me out a little bit and checking my math for me. I've been trying to find someone with an accurate answer.... I recently purchased 4 lightly used 270 watt, 35.5 volt, 7.60amp pmax / 15amp fuse rating solar panels. So, if I connect them up in series I would get 1080watts with 142 volts at 7.6 amps. Correct? I also purchased a DC pool pump rated at 72vdc that comes with a 72v Controller Box. The Controller parameters are as follows: Rated current=12A, max solar input volts=150, current overload=15A, pump=1000W @ 72v, best working volts=88v. Would you agree that my 4 panels in series is best and most efficient? Or do you recommend another configuration???

[@OffGridGarageAustralia]

I haven't got all parameters but from what you're stating, this should work under best solar conditions. Not sure what the controller does when solar is not at its best. Does it just throttle the pump?

[@VIAMediaGroup]

@@OffGridGarageAustralia I think that's what it does unless I'm using batteries, which I'm not planning on doing initially. I'm also leaving the AC pump connected to the system with both pumps having check-valves on their outlet sides to prevent backflow. With a flow-meter switch when the sun goes away the AC pump kicks on until sufficient sunlight and flow from the DC side. That's the plan.

[@MrSummitville]

@@VIAMediaGroup Exactly what is "35.5 Volts" ??? Is it Vmp or Voc? Because Max Voc per Panel may be limited to only 37.5 Volts = 150v / 4. What happens if you exceed the 150 Volt Max Input limit of the controller?

[@VIAMediaGroup]

@@MrSummitville open circuit voltage=44.4 and V pmax=35.5

[@MrSummitville]

@@VIAMediaGroup 177.6 Volts = 44.4 Volts x 4. Will your controller handle 177.6 Volts?

[@zxrjimmy1]

Why not cut the trees

[@OffGridGarageAustralia]

I discussed this already. Because they are 100+ year old trees... You never cut down trees for solar panels. That is stupid and contradict the purpose of saving energy, carbon emissions and helping the environment.

[@zxrjimmy1]

@@OffGridGarageAustralia I mean just trim the tops, we done it here and made big difference to solar panels

[@Jack2of3]

Just be concerned with the watts.

[@jethrotull5847]

Still too many variables involved. Get an ESP-32 and some voltage / current sensors, create a script and hook the sensors to each panel sting. Basically.. create a Solar panel “BMS” of sorts. 3D print weather proof boxes. Each ESP-32 connects wirelessly to a dedicated AP and publishes data to a Pi based MTTQ server and then node red creates a dashboard. Hook 1 ESP-32 per solar panel X 3 sensors and mount panels to roof. All. Data is logged to influxdb on pie. So data is collected under all variables with each panel exposed equity. Bust open a six pac and simply collect data for a couple of months.. content that you will identify bad cells and the conditions that aggravate it. You have also learned something and developed a system for any future failure. Winner, Winner chicken dinner. Im sure I got something ass backwards. Everything would have to be engineered ( for instance a ESP-32 is a 3.3 or 5 volt device ) lastly, it has many digital outputs that can be used to control a relay possibly bypassing a bad panel. Just a thought.

[@jethrotull5847]

Arg.. got some things just wrong. As with a BMS you would “tap” the most negative pole on the string and work up to each positive. The ESP-32 uses an I2C buss so it’s capable of reading voltages at the source, converting it to digital avoiding loss from long wire resistance . An I2C buss can handle many sensors each just need a unique address. Good news it would dramatically cut down the amount of devices required. Back to the drawing board.....

[@andrewjackson3761]

First love your channel . You are looking for something wrong but all your seeing is degregation of cells with age . Modern panels lose about 15% over 10 years . 5 amp to 4 amp is 20% , I don't know what degradation was in order panels . But simply solar cells same as batteries degrade over time . You expect a battery to lose capacity and the wires are all working, so just realise thar solar cells degrade over time and depends on there earlier life , did they get very hot or anything like that . On older panels you just need to test to reevaluate any degradation . 80% after 10 years on second hand panel not to bad . Once again love your channel and have learnt many things

[@OffGridGarageAustralia]

Thanks Andrew. It seems like the cells from my first pick up are not OK and work quite differently to the ones I picked up recently. Same brand and model. Degradation should not be more then 1% in 10 years. I tested a few panels ones on my house and still could get 98-99% out of them. Same as with the first one I tested here in the video. But yes, they will degrade over time.

[@andrewjackson3761]

@@OffGridGarageAustralia well I've just been looking at buying some panel's and the best guarantee I have found is 85% after 20 years , that's best most are 10 years . I'm based in UK and would love to find solar panel's with a guarantee of 1% degradation , if you could just give me brand name so I can research , I'm pleased that I didn't buy the ones I saw I have obviously been looking at wrong thing and have been confused with all the information and figures they talk about , thank you for pointing this out to me

[@MrSummitville]

@@OffGridGarageAustralia Degradation can be any value. Most panels will fall between between 0.1% / year = GOOD and 2% / year = JUNK. Heat ( roof mount ) degrades panels faster than ground mount ...

[@opless]

Tenth! 😁

[@fultonhoward2917]

Get some new diodes mine were 20 for 5dollars delivered try them and then you will know do not be to hard headed over it compared to what you have paid for these panels that is noting. And it is one of the only things you can do to fix a panel. If either of your tester shows a diode is bad replace it. Simple

[@OffGridGarageAustralia]

It's not the diodes. Some panels even have no diodes and don't work properly either. It's in the video, btw ;)

[@MrSummitville]

@@OffGridGarageAustralia Unfortunately, YOU keep saying, "These diodes showed reverse current."

[@amudlifecrisis]

Just group all the good ones together on the same controller then make another array of the poor performance panels on another controller, they're still making power.

[@OffGridGarageAustralia]

Yeah, something like this is the plan...

[@michaelbouckley4455]

Still usually best to have all the same make & type in an array. eg, all Suntech, as you have a lot of. Not mixing 190 Watt with the bigger ones

[@notyoung]

In a video titled "The Effectiveness of Staggering Fixed PV Solar Panels" kzbin.info/www/bejne/mJ_aZqKIgp56q8U there are some good charts about when you'll have the most power from your solar panels. Basically, you get less than 80% of rated output as soon as you pass the 2 hour mark away from solar noon. Three hours away from solar noon you only get 65% of rated output and so forth. 6.3 amps is 74% of 8.5 amps so how far were you from solar noon at your location? You can determine solar noon for any location here: www.esrl.noaa.gov/gmd/grad/solcalc/

[@peterdkay]

Interesting Will Prouse video at kzbin.info/www/bejne/mV7EpoV-gNZlY6M. He found open circuit voltage for used panels is a good guide to quality.

[@mikeman230]

Time for some trees to die

[@offgridwanabe]

As far as the junkers go hook them all up in series and get a high voltage buck converter to charge or run your testing equipment

[@offgridwanabe]

20 volts different for the Mppt from the 2 types this may knock down the production a little when combining the strings but it will still be 100% better than the broken ones and you can check that at your one of a kind junction box lol Cheers buddy