I’m not sure this applies in this case but I have a saying I always keep in my hip pocket. “Never be afraid to give up on a mistake even though you spent a lot of time making it“. I love your tenacity, your creativity, and your bulldog attitude in trying to solve this problem. I truly wish you the best.
For panel testing you can use the low cost open PCB battery load tester with fan/cpu heatsink but you should get the models with CV control which is models with side push buttons, not the ones with control knobs which lack the CV control. They come in 150 to 190 watt max power dissipation (limited by heatsink/fan) and are in $70-$80 range. They have mode control of constant current, constant voltage, constant resistance, or constant power control. For PV testing you want the feature of constant voltage control which the slightly lower cost battery testers do not have. A full cased model load tester is Kunkin KP184 that is 150v max, 40A max, kept within 400 watt max. If you have 300w panels this would be a good choice. They are about $150-$160. On CV control mode, it acts like an electronic high power adjustable zener diode. You set the CV limit voltage around Vmp and adjust the CV voltage up or down while watching unit's power readout. Adjust the CV setting to maximize wattage reading, which will be actual Vmp for illumination and temperature conditions at time of test. It will give you the panel current at the voltage limit you adjust to. You can drop the CV voltage down to 10-50% of panel's Vmp and the current readout will be close to Isc. Adjusting CV between Vmp and Voc will show you the rate of output current drop off at non optimum panel loading above MPPT point, all dependent on present temp of your panel. At CV limit where current drops to zero is Voc for given panel temp and illumination.
The angle of your panels into the sun. Make a significant difference. To the point to where you can go from 60 watts to 400 watts, merely by changing the angle of your panels into the sun. Rick from Fort Worth, Texas
Hi Andy, glade to hear you can step away. FYI Amazon - Fielect Wirewound Ceramic Potentiometer Rheostat Variable Resistor with Knob 500W 500R ... $12.29
Yeah, I just don't want to carry a whole lot of stuff when I pick up solar panels and test them on-site. So I hope the tester will work and gives me a quick summary of the performance of the panel.
I think 135 watt output is reasonable for real world performance. Edited to add the max power calculation equation. And correct the equation. Isc = I from solar. It is a direct measure of solar irradiation. The numbers on the sticker are for STC standard test condition of : T_stc=25; deg C Am atmosphere factor of 1.5; E_stc solar radiation 1000 W/m^2; ISC is ISC_stc comes from solar panel label on the back. P_max is Pmax_stc comes from solar panel label . VOC_stc is the VOC from the label. E_real is probably 800 to 900 W/m^2 at this time of year. We can test this.. Real_T you mentioned = 54 dec C that is very hot. The nom temp on the back lable (45) is what is used to represent the likely real performance. Isc = ( ISC_stc - ISC_stc*0.0005 * delta_T) *ratio Where ratio =Real_E/E_stc Delta_T = Real_T - T_stc The constant k is the temperature coefficient for current expressed as 0.05% (0.0005) . Since the temperature change 54-25*k is only about 1%, we can assume the ration of Real_ISC to ISC_stc is the ratio of the change of energy in the real world. Ratio E =4/5 Amps ISC =0.8. The constant varries between 0.35 to 0.5% for the power temperature coefficient depending on quality. 0.5% (0.005) is used if not mentioned on the data sheet as the temperature coefficient. I calculated 130 W peak power, but the picture of the lable was fuzzy in the video. P_max = (Pmax_stc - Pmax_stc*0.005*delta_T)*ratio Let the energy ratio = 0.8 Let delta_T = 54-25 Pmax = (190-190*0.005*(54-25)*0.8 Pmax = 130 watts/m^2 I think it is right now. Real world performance is going to be between 70 to 80 percent of the label wattage.
@@OffGridGarageAustralia I tried to send a picture of the schematic of a single cell, but could not figure out how to do it on TH-cam. So I created a text character schematic in one of these comments. Yeah I am old, the first computer I used was the size of a big box store. My phone has more power than that thing.
Thanks Andy you've caused me to go on a journey of purchasing my first solar system and now the bloody tester... Love your video's so Funtastic ... Soon I'll be ordering a battery...
In case you didn't know, you can parallel those capacity testers. Generally not a good idea to run them at maximum, they tend to get toasty, and not a part with a heatsink. Never mind, I see it burned out, usually a diode close to the MOSFET. The MOSFET has the heatsink, a diode next to it gets about 100 Celsius and cooks. Could of course be the MOSFET as well. It is the most common failure.
I checked the FET and it seems to work fine. Well, at least when it's cold. There are two diodes right next to it. I haven't tested them yet. The problem is the current flows fine for a few seconds and then drops to zero before it it goes somewhere in between. It's just not constant any eventually goes to 0A. Also the fan does not turn on any more either...
Same thing with me, I connected a 56 volt pack up to mine and sparks flew out of it with the pots turned all the way down. The big moset under the fan, a IRF260 Power MOSFET, and it had a crack and a burn mark in it. Replaced it and it works again but I suspect the thing can't handle voltages much higher than 24 volts which I tested fine with it. Just did a capacity test of my latest batch of the 280Ah batteries with it.
Hey Andy, thanks for all the videos. Im keen to see the solar tester in operation. I am a bit sceptical that this unit will be able to dissipate up to 400w of power. Hopefully it does🤞. Thanks again, great content, keep it coming.
Thanks Matthew. I'm sceptical too. Apparently, it tests the MPP only for a short moment over a shunt so allows it to cool down in between these measurement intervals. We will see...
If designed properly it will only be loading the load transistors for a few tens of milliseconds, since PV module response to load changes is virtually instantaneous.
@@OffGridGarageAustralia After testing my own 2nd hand panels i came across another way to check panels without a tester. I had a supposedly mppt controller that wasnt. Basically, it just pulled max current from panel. I was using 12v battery. This made me think that, as the panel is basically a constant current source across most of the voltage range, you could just connect the panel to a partially discharged battery that has voltage lower than the mpp and just measure the current. It will be close to the mpp current and good enough to weed out shitty panels.
Love that you are reading comments and talking about them. Sorry to see your tester is dead. Why not just get another? You will probably use it for other things.
I made a tester out of 2 dome light bulbs in series....works okay...if they're not making amps it won't get very bright but it's pretty dependable. Not really complicated.
We'll see if it can handle the 400W, right? Someone said it only calculates the numbers out of Voc and Isc and does not do real MPPT. That would be lame 🤔
@@OffGridGarageAustralia So are these units any good? as in good enough to test used panels on the fly to at least see if the panels are junk or not before you buy them and then later can always test with something better to see true panel output.
Andy, not sure if this will help but in the US a hot water heater element for 240v 4500w is actually a 12 ohm resistive heating element. In water that may be a good load test instead of a 10 ohm resistor. Brian
I just ordered a West Mountain Radio CBA IV Pro battery analyzer to test my LiFePO4s. As a pleasant surprise, I discovered it also analyzes and plots the MPPT curve of solar panels! I'll provide more details if you like.
Hi as a new bee I’ve come across you channel and found it interesting as I’m setting up solar lithium 12 v on my boat. Using Epever mppt 30Ah with mt50. I think you did a show on how to set up the mt50 which I found very informative i didn’t save that show and can’t find it .I would appreciate it if you could point out the video for me ..I’ve tried to follow others but it just get confusing ,as someone that knows very little this .. your explanation was easy to understand Cheers.
ITS THE DIODES!! It's NOT a DREAM! ITS REAL! haha.. Good stuff as always Andy, and Thank you again. I sent a link to your YT channel from my last video as well.. I have to admit though, on my video I told everyone it was your fault for the beer drinking! hahaha.. Cheers my friend!
Great video. I have a similar meter (with digital button control) and it is not accurate most of the time if the supply voltage is below 6V. I think some TH-cam reviews also pointed it out. I am curious if that is the problem. I use a QC/PD trigger to get 9/12V from a Fast Charging Powerbank as a portable supply.
Thanks for the info! I'll connect it back to the 12V power supply and see if this makes a difference. I had it running from the power bank before and it worked fine.
With your new mppt tester you want to match the panels with the same current in each string at their MPPT. Then put a big sticker "Now With Current Matched strings".
Instead of a resistor, you can use incandescent lightbulbs, halogen, or even car bulbs in series, you can also use resistance wire, to make it adjustable, but house light bulbs will work, just parallel to get the needed load current, at 230-240 volts maybe 4-8 parallel, depending on the wattage, but try to equal the panel to test the mpp!! But I'd just use a DC to DC boost converter, with a power meter between, and use bulbs as a load, more voltage out, is more current in! I guess a buck converter with 12v bulbs would also work, the meter will show the watts ,amps and volts, it's a start anyway!
I corrected my comment in the calculation of real ISC and added the equation to calculate the real max power point. I used ISC to calculate the change in solar radiation W/m^2. Changed the temperature coefficient for current to 0.05% Added the Power temperature coefficient to 0.5 %
Thanks for tip re the tester. Have just ordered one too. I have the small black shunt Meter, but find it frustrating as it does show current AH in and out separately, just the total net value. Otherwise relative genau.
I'd ditch the old 200w panels. I reused my ~10year old Sharp 220W panels & they were putting out good power. Then I found you can get brand new 400w panels for about 30-40c/w, thats $140 for a brand new 400W panel from local distributors in Australia, add GST & Pickup & you get HUGE improvements in capacity.
Remember radiant cooker rings? About £8 for 2kW at 230Volts.... they make great high power lowish value resistors for lower voltage DC testing.... ....as do hairdryer or electric fan heaters or.... Just series/parallel for different values. You get the picture 😁👍
Sorry to hear your electronic load isn't funtioning anymore Andy, it seemed like a good way of testing, could shade cause an inverse polarity on the inputs? Good luck with your solar projects!
I'll repair the electronic load. Can't be much to get it fixed. Shading does not cause any reverse polarity, it just lowers the voltage of this particular string and panel.
Have you checked your polarity? Low amperage, burned tester.......????? I believe the Victron will work but not very well if the polarity is reversed. It's easy to do with all the connections. I've had panels with the cables reversed. When I put the one in series with the rest it destroyed the output. Are you testing polarity on each panel individually? From your presentation, you've used the process of elimination and done a step by step troubleshooting technique which is the ideal way to go about figuring the issue. But sometimes the simplest things are missed in the process. I worked as a control troubleshooter for years and even with my eating and $hitting controls I would have equipment where I would overlook something so simple. Sometimes I'd have to grab a fellow worker to doublecheck my efforts.
Hi Andy...probably you will unbox the Zke Tester....well I finished my battery test...put all together in one excel file....at least it shows very clear...voltage doesn't say anything about SOC..and also it seems that I received a mix of batteries...some have similar charging behaviour......if you want me to send the file just drop me a note...where to load it up.
...and a thought about the faulty panels....the backside of the panels is covered with a selfadhesive plastic foil....that material is ageing by loosing the plastiziser...maybe also it is also slightly loosing the stickiness...if so the backside is not perfectly isolated any more...and the panels where used close to the seaside and the air there is bit more salty you have some electrolytes that might have contaminated the backside.....maybe that has an impact...if the backside is not sealed that perfect as it was when the panel was new........just a silly thought of mine....
Are you 100% positive that this device actually finds the true MPPT via a Search, P&O or Conductance algorithm vs simply computing what the MPPT "SHOULD BE" from simply measuring the Voc * Isc ?
@@MrSummitville well now you've injected some doubt in my mind so I'll have to test it when it arrives to be sure. If it doesn't actually find the real maximum PowerPoint then it would be what I call a scam.
@@SiriusSolar How can that device put a 400 Watt Load, on 400 Watt Solar Panel? I don't think they can fit a 400 Watt Resistor inside of that little box. They may be using a variable PWM with a very fast Max Power Point Tracking sweep for a very, very short time? Maybe? And then they need to cool that under-sized load resistor for 15 seconds? HOW it actually measures, or computes, the Max Power Point needs to be explained by the manufacturer ...
@@OffGridGarageAustralia You can NOT measure Vmp & Imp at the same time with a low ohm shunt. The ohms value of a shunt is way too low to achieve Max Power Point. But, you can use a shunt to easily measure Isc. See my previous, reply just above your reply, regarding my theory of operation using a variable PWM, a very fast MPPT sweep and undersized load ( which you call a shunt ) to determine Max Power Point. Typically, a shunt does not need a "Cool Down" cycle, but an Under-Sized Load will require cooling time. Also, yesterday I wrote, "... HOW this device actually measures, or computes, the Max Power Point needs to be explained by the manufacturer ..."
One more comment to make sure the polarity of solar panel temperature coefficients are correct. K*( Real_T - T_stc) Pmax should go down with increased temperature. ~0.5%/deg_C (0.005) ISC should go up a little bit with increased temperature. ~ 0.05%/deg_C (0.0005) small enough change to ignore, so you can use it as a relative solar intensity measuring tool. VOC should go down with increased temperature. ~0.3 to 0.4%/deg_C (0.004) ~ means approximately
Bei deinem Tester ist der MOSFET kaputt🤔 ich musste den bei mir schon zweimal tauschen da ich zu weit gegangen bin😅 ich habe einen Typ IRFP 260N verbaut. Bei den anderen Tester bin ich schon wirklich gespannt 🙂 Ich nutze für meine Tests einen EBC A20 von ZKE Tech und bin sehr zufrieden. Schöne Grüße
you can get these variable resistors on aliexpress for very reasonable prices, and absolutely massive ones capable of multiple kw. been thinking of buying one myself for testing cells but under very high C rates, for ebike/e-motorbike
I'm really looking into a more reliable and clean solution. When I pick up solar panels, I don't want to setup equipment and find the MPP manually. I'll try this Solar Panel Tester and see how it works.
Hi Andy, when you end your videos you need too add to "stay safe, stay charged "and stay pissed then you no need to worry if the panels are working or not. Hahahaha
What was the resistance across a working string on one of your panels where the diode worked correctly and a string that had a failed test on the diode? You can use the Ohms setting on your multimeter to check resistance through the string and diodes. I'm wondering what the resistance measures on the diodes that were showing open in both directions?
from an old teck pro- High current resistor-Instead.Cheap local version is old hot plate element with exposed nichrome wire then use your alligator clips
i’m curious of what is the resistance on a oven element (you know the thing in spiral which heat your soup), that can take enough current and will not blow if used below 120v.. it’s an idea to explore if you have a spare element somewhere!!
Better would be to use something above the testing voltage (like 120V/220V bulbs) and add in parallel as needed. A non electronic dimmer could also be used to fine tone it.
I have the same tester with the fan and dials, except mine is 180 watts, and has a different cooler on it, and any time I use it above 1.6 amps, it starts making a weird noise, like one of the circuits is dying.
The manual says 150W/180W but needs a different cooling for 180W. They don't say what needs to be changed though... They seem to have a fragile circuit design. This is already the second one which died.
@@OffGridGarageAustralia the only difference between yours and mine, is I bought the model with a bigger cooler that has two fans. Doesn't matter how big the cooler is, if I can't have it draw more than 1.6 amps before it starts sounding like a component is dying.
You open the boxes, now you can measure your mc4 connectors (corrosion, full contact) John might live in USA or UK look for the measurement (Zoll/inches) ;o) Prost walter
There is a possibility that there is no big/heavy load during the testing, and the battery is fully charged already. What if while trying to run solar panel, connect some big/heavy load (e.g. electric stove/heater/vacuum cleaner/etc...) and check the running current.... Probably there is no problem with the solar panels.... just not enough load to make the high flow of the current.....
Recently, I became aware that the DC-AC inverter can be the choke point of how much power we can harness and use. Anybody have a link for an inverter that is more user friendly than 10.5 to 15 V (12volt version)?
I think you have problem with shading,first.I can suggest to prune the trees little bit, or you could use half-cut panels that perform better with shade. I have 8 x 470 Watt half cut panels and I got maximum 3700 watt.I have Hibrid inverter with Mppt controller inside inverter. I suggest also to try to push more from your panels by applying more load to the system, to see if you can get more Power. Other thing is Mppt charger:different Mppt handle Volt & Amp in different ways. Other thing:you should first power off the Mppt Charger and Inverter before you reconnect the solar panels cables to the system...to avoid to damage Mppt charger and Inverter.
I cannot prune the trees and it would make no sense. This is the situation I have and it will not change. Half-cell panels may be better but are also more expensive. I've not bought any new panels yet but only these used ones.
Is it possible that the capacity tester died, because the powerbank went off? Most of those newer powerbanks switch off if whatever is connected to them doesnt draw enough current. In that case the capacity tester has no fan for cooling anymore and also it cannot regulate he voltage and power anymore. Der schöne große Drahtwiderstand erinnert mich auch an die Schule. Habe vor einiger Zeit mal auf Ebay usw. danach gesucht, aber sowas findet man heute gar nicht mehr. Einfache Hochlastwiderstande für 100W gibt es aus Ebay allerdings massenweise für ein paar Dollar, z.B auch als Zweierpack mit 20 Ohm. Parallel geschaltet wären das die gesuchten 10Ohm für 200W.
In plain American english, if in full sun clear skys, about noon you measure ISC about 4 amps, and Measure VOC 20% less than VOC @ stc your panel is probably good. Then if you measure ISC on the roof shortly after and it gives you much less than 4 anps with the clear sky, you have more of a tree? shadow than you realize or the Real panel Temperature is much much higher on the roof than on the ground. If you measure
We've got lots of large trees around, but they are not the problem. It is very clear that the panels will not perform as well when shaded. That is not the problem.
@@OffGridGarageAustralia read my other comments where I went through the calculation for thermo coefficients. I can up with an estimate of 130 watts is a representative of a good panel.
Why are we now concentrating on 36.6Voc panels ? The original problem was with 44.5Voc panels. Three of the former worked fine, the latter did not. Checking the latest batch of 36.6Voc panels whilst interesting and educational, will not solve the original problem. The issue remains the charge controller hitting the magic 130v.
@@OffGridGarageAustralia Not confuse, 51 seconds in 36.97Voc. Original problem panels in episode 6, 2min 50 seconds in, Suntech 45.2Voc and Renesola 44.5Voc. You stated your new system was 145v and the old 105v, with the new system being the problem. The charge controller manual says MPTT limit is 130v. You also had previous problems with the charge controller locking out at 132v, now fixed but how ? Your new "problem" panels exceed this voltage, so where do you think the problem might be ?
@@benjones8977 aha that makes more sense! I’ve got 340-345 watt panels, as they worked out to be the best bang per buck, and keeps panels sized 1.7m x 1.0m.
@@iainkay3630 Yes sometimes I’m just tired & don’t think things through. It was a long hard ordeal to go off grid, I now have 6 kW of PV and 9.6 of lithium batteries. Being somebody who didn’t know a thing about electricity, it’s nice to know if you have an interest you can achieve it!
@@benjones8977 that is really good work! I’m not going to be in this property long enough to take it off grid but want to run my PV and Battery set up alongside it parallel to reduce my environmental impact and bills - all whilst doing the set up in a relatively easy to remove fashion.
becomming slave of the first charger (master) of different software level. So it does not see the battery voltage but the master voltage and reduces the aps.
I’m not sure this applies in this case but I have a saying I always keep in my hip pocket. “Never be afraid to give up on a mistake even though you spent a lot of time making it“. I love your tenacity, your creativity, and your bulldog attitude in trying to solve this problem. I truly wish you the best.
Thank you 😉
I would never 'give up' on any troubleshooting job, ever. I might seek outside help but not give up. I doubt I could ever sleep again.
@@aday1637 I can respect your tenacity. But there’s an old saying “sometimes it’s easier to plow around the stump”
For panel testing you can use the low cost open PCB battery load tester with fan/cpu heatsink but you should get the models with CV control which is models with side push buttons, not the ones with control knobs which lack the CV control. They come in 150 to 190 watt max power dissipation (limited by heatsink/fan) and are in $70-$80 range. They have mode control of constant current, constant voltage, constant resistance, or constant power control. For PV testing you want the feature of constant voltage control which the slightly lower cost battery testers do not have.
A full cased model load tester is Kunkin KP184 that is 150v max, 40A max, kept within 400 watt max. If you have 300w panels this would be a good choice. They are about $150-$160.
On CV control mode, it acts like an electronic high power adjustable zener diode. You set the CV limit voltage around Vmp and adjust the CV voltage up or down while watching unit's power readout. Adjust the CV setting to maximize wattage reading, which will be actual Vmp for illumination and temperature conditions at time of test. It will give you the panel current at the voltage limit you adjust to. You can drop the CV voltage down to 10-50% of panel's Vmp and the current readout will be close to Isc. Adjusting CV between Vmp and Voc will show you the rate of output current drop off at non optimum panel loading above MPPT point, all dependent on present temp of your panel. At CV limit where current drops to zero is Voc for given panel temp and illumination.
The angle of your panels into the sun. Make a significant difference. To the point to where you can go from 60 watts to 400 watts, merely by changing the angle of your panels into the sun.
Rick from Fort Worth, Texas
Yes, that is true Rick. More testing underway...
Hi Andy, glade to hear you can step away. FYI Amazon - Fielect Wirewound Ceramic Potentiometer Rheostat Variable Resistor with Knob 500W 500R ... $12.29
Yeah, I just don't want to carry a whole lot of stuff when I pick up solar panels and test them on-site. So I hope the tester will work and gives me a quick summary of the performance of the panel.
I think 135 watt output is reasonable for real world performance. Edited to add the max power calculation equation. And correct the equation.
Isc = I from solar. It is a direct measure of solar irradiation.
The numbers on the sticker are for STC standard test condition of :
T_stc=25; deg C
Am atmosphere factor of 1.5;
E_stc solar radiation 1000 W/m^2;
ISC is ISC_stc comes from solar panel label on the back.
P_max is Pmax_stc comes from solar panel label .
VOC_stc is the VOC from the label.
E_real is probably 800 to 900 W/m^2 at this time of year. We can test this..
Real_T you mentioned = 54 dec C that is very hot. The nom temp on the back lable (45) is what is used to represent the likely real performance.
Isc = ( ISC_stc - ISC_stc*0.0005 * delta_T) *ratio
Where ratio =Real_E/E_stc
Delta_T = Real_T - T_stc
The constant k is the temperature coefficient for current expressed as 0.05% (0.0005) .
Since the temperature change 54-25*k is only about 1%, we can assume the ration of Real_ISC to ISC_stc is the ratio of the change of energy in the real world. Ratio E =4/5 Amps ISC =0.8.
The constant varries between 0.35 to 0.5% for the power temperature coefficient depending on quality.
0.5% (0.005) is used if not mentioned on the data sheet as the temperature coefficient.
I calculated 130 W peak power, but the picture of the lable was fuzzy in the video.
P_max = (Pmax_stc - Pmax_stc*0.005*delta_T)*ratio
Let the energy ratio = 0.8
Let delta_T = 54-25
Pmax = (190-190*0.005*(54-25)*0.8
Pmax = 130 watts/m^2
I think it is right now.
Real world performance is going to be between 70 to 80 percent of the label wattage.
Wow!
@@OffGridGarageAustralia I tried to send a picture of the schematic of a single cell, but could not figure out how to do it on TH-cam.
So I created a text character schematic in one of these comments. Yeah I am old, the first computer I used was the size of a big box store. My phone has more power than that thing.
I blew up my tester as well, contacted them and they say to replace the mosfet! Havent had a chance to replace it yet tho!
I un-soldered the MOSFET and it works perfectly fine. Mine has got another issue. I've sent them a video with the fault...
Thanks Andy you've caused me to go on a journey of purchasing my first solar system and now the bloody tester... Love your video's so Funtastic ... Soon I'll be ordering a battery...
Thank you. Yeah, get your battery!
In case you didn't know, you can parallel those capacity testers. Generally not a good idea to run them at maximum, they tend to get toasty, and not a part with a heatsink. Never mind, I see it burned out, usually a diode close to the MOSFET. The MOSFET has the heatsink, a diode next to it gets about 100 Celsius and cooks.
Could of course be the MOSFET as well. It is the most common failure.
I checked the FET and it seems to work fine. Well, at least when it's cold. There are two diodes right next to it. I haven't tested them yet.
The problem is the current flows fine for a few seconds and then drops to zero before it it goes somewhere in between. It's just not constant any eventually goes to 0A. Also the fan does not turn on any more either...
Hi Andy, my load tester did the same and I was within spec. I replaced the large Mosfet under the cooler and all good. Kind Regards Dave G
Same thing with me, I connected a 56 volt pack up to mine and sparks flew out of it with the pots turned all the way down. The big moset under the fan, a IRF260 Power MOSFET, and it had a crack and a burn mark in it. Replaced it and it works again but I suspect the thing can't handle voltages much higher than 24 volts which I tested fine with it. Just did a capacity test of my latest batch of the 280Ah batteries with it.
@@bluejeanvanlife8627 it needs to be precharged with a resistor
@@zarbonida Shouldnt have to, there are no big caps on it. You are thinking of the inverter.
I un-soldered the FET and it works fine. Well, when it's cold at least.
Hey Andy, thanks for all the videos. Im keen to see the solar tester in operation. I am a bit sceptical that this unit will be able to dissipate up to 400w of power. Hopefully it does🤞. Thanks again, great content, keep it coming.
Thanks Matthew. I'm sceptical too. Apparently, it tests the MPP only for a short moment over a shunt so allows it to cool down in between these measurement intervals. We will see...
If designed properly it will only be loading the load transistors for a few tens of milliseconds, since PV module response to load changes is virtually instantaneous.
@@OffGridGarageAustralia After testing my own 2nd hand panels i came across another way to check panels without a tester. I had a supposedly mppt controller that wasnt. Basically, it just pulled max current from panel. I was using 12v battery. This made me think that, as the panel is basically a constant current source across most of the voltage range, you could just connect the panel to a partially discharged battery that has voltage lower than the mpp and just measure the current. It will be close to the mpp current and good enough to weed out shitty panels.
Check the MOSFET on that electronic load tester, I have blown my when trying to draw more than 20A.
Checked and tested OK
Same happened to my tester. I replaced the mosfet and it works fine again.
I have a broken one also. Sounds like I need to check mosfet.
MOSFET works fine. At least when it's cold.
Love that you are reading comments and talking about them. Sorry to see your tester is dead. Why not just get another? You will probably use it for other things.
I try to read and respond to as many comments as possible. But there are so many now...
I'll try and repair the tester first.
I made a tester out of 2 dome light bulbs in series....works okay...if they're not making amps it won't get very bright but it's pretty dependable. Not really complicated.
I ordered two of these haha can't wait to see if it's trash. Simple device so in theory it should work well haha
We'll see if it can handle the 400W, right? Someone said it only calculates the numbers out of Voc and Isc and does not do real MPPT. That would be lame 🤔
@@OffGridGarageAustralia So are these units any good? as in good enough to test used panels on the fly to at least see if the panels are junk or not before you buy them and then later can always test with something better to see true panel output.
Can't wait for your surprise, keep up the good work
Thank you very much Wally!
Andy, not sure if this will help but in the US a hot water heater element for 240v 4500w is actually a 12 ohm resistive heating element. In water that may be a good load test instead of a 10 ohm resistor.
Brian
Thank you.
I just ordered a West Mountain Radio CBA IV Pro battery analyzer to test my LiFePO4s. As a pleasant surprise, I discovered it also analyzes and plots the MPPT curve of solar panels! I'll provide more details if you like.
Oh, wow, that's great. I'll check it out!
Hi as a new bee I’ve come across you channel and found it interesting as I’m setting up solar lithium 12 v on my boat. Using Epever mppt 30Ah with mt50.
I think you did a show on how to set up the mt50 which I found very informative i didn’t save that show and can’t find it .I would appreciate it if you could point out the
video for me ..I’ve tried to follow others but it just get confusing ,as someone that knows very little this .. your explanation was easy to understand
Cheers.
Hello and welcome. Thanks for your feedback.
Sorry I have not used an Epever in any of my videos. That must have been on another channel...
ITS THE DIODES!! It's NOT a DREAM! ITS REAL! haha.. Good stuff as always Andy, and Thank you again. I sent a link to your YT channel from my last video as well.. I have to admit though, on my video I told everyone it was your fault for the beer drinking! hahaha.. Cheers my friend!
Thank you very much Dan. IT"S THE BEER!!!! 🍺🍺🍺
you can adjust that capacity load tester, i bumped mine up to 210 watts and have had no problems
How?
Great video. I have a similar meter (with digital button control) and it is not accurate most of the time if the supply voltage is below 6V. I think some TH-cam reviews also pointed it out. I am curious if that is the problem. I use a QC/PD trigger to get 9/12V from a Fast Charging Powerbank as a portable supply.
Thanks for the info! I'll connect it back to the 12V power supply and see if this makes a difference. I had it running from the power bank before and it worked fine.
With your new mppt tester you want to match the panels with the same current in each string at their MPPT. Then put a big sticker "Now With Current Matched strings".
Yes, that is exactly the plan.
Instead of a resistor, you can use incandescent lightbulbs, halogen, or even car bulbs in series, you can also use resistance wire, to make it adjustable, but house light bulbs will work, just parallel to get the needed load current, at 230-240 volts maybe 4-8 parallel, depending on the wattage, but try to equal the panel to test the mpp!! But I'd just use a DC to DC boost converter, with a power meter between, and use bulbs as a load, more voltage out, is more current in! I guess a buck converter with 12v bulbs would also work, the meter will show the watts ,amps and volts, it's a start anyway!
I corrected my comment in the calculation of real ISC and added the equation to calculate the real max power point.
I used ISC to calculate the change in solar radiation W/m^2.
Changed the temperature coefficient for current to 0.05%
Added the Power temperature coefficient to 0.5 %
All your videos are Excellent...Love from India...
Same here, replaced the mosfet two times now. They burn down realy easy :)
I checked the power MOSFET and it is working correctly.
Hi Andy,...you find that old school resistors in simple welding devices....
Thanks for tip re the tester. Have just ordered one too. I have the small black shunt Meter, but find it frustrating as it does show current AH in and out separately, just the total net value. Otherwise relative genau.
I'd ditch the old 200w panels. I reused my ~10year old Sharp 220W panels & they were putting out good power.
Then I found you can get brand new 400w panels for about 30-40c/w, thats $140 for a brand new 400W panel from local distributors in Australia, add GST & Pickup & you get HUGE improvements in capacity.
Remember radiant cooker rings? About £8 for 2kW at 230Volts.... they make great high power lowish value resistors for lower voltage DC testing....
....as do hairdryer or electric fan heaters or....
Just series/parallel for different values.
You get the picture 😁👍
Sorry to hear your electronic load isn't funtioning anymore Andy, it seemed like a good way of testing, could shade cause an inverse polarity on the inputs? Good luck with your solar projects!
I'll repair the electronic load. Can't be much to get it fixed.
Shading does not cause any reverse polarity, it just lowers the voltage of this particular string and panel.
Have you checked your polarity? Low amperage, burned tester.......????? I believe the Victron will work but not very well if the polarity is reversed. It's easy to do with all the connections. I've had panels with the cables reversed. When I put the one in series with the rest it destroyed the output. Are you testing polarity on each panel individually? From your presentation, you've used the process of elimination and done a step by step troubleshooting technique which is the ideal way to go about figuring the issue. But sometimes the simplest things are missed in the process. I worked as a control troubleshooter for years and even with my eating and $hitting controls I would have equipment where I would overlook something so simple. Sometimes I'd have to grab a fellow worker to doublecheck my efforts.
Hi Andy...probably you will unbox the Zke Tester....well I finished my battery test...put all together in one excel file....at least it shows very clear...voltage doesn't say anything about SOC..and also it seems that I received a mix of batteries...some have similar charging behaviour......if you want me to send the file just drop me a note...where to load it up.
How do you know???? It's in the next video tomorrow. What a great device!
...and a thought about the faulty panels....the backside of the panels is covered with a selfadhesive plastic foil....that material is ageing by loosing the plastiziser...maybe also it is also slightly loosing the stickiness...if so the backside is not perfectly isolated any more...and the panels where used close to the seaside and the air there is bit more salty you have some electrolytes that might have contaminated the backside.....maybe that has an impact...if the backside is not sealed that perfect as it was when the panel was new........just a silly thought of mine....
Thanks Frank. I checked the panels for any cracks. We also have not much moisture here and none of the panels actually shows any sign of water damage.
I ordered one with your link. I'm in Hawaii so shipping takes forever
Are you 100% positive that this device actually finds the true MPPT via a Search, P&O or Conductance algorithm vs simply computing what the MPPT "SHOULD BE" from simply measuring the Voc * Isc ?
@@MrSummitville well now you've injected some doubt in my mind so I'll have to test it when it arrives to be sure. If it doesn't actually find the real maximum PowerPoint then it would be what I call a scam.
@@SiriusSolar How can that device put a 400 Watt Load, on 400 Watt Solar Panel? I don't think they can fit a 400 Watt Resistor inside of that little box. They may be using a variable PWM with a very fast Max Power Point Tracking sweep for a very, very short time? Maybe? And then they need to cool that under-sized load resistor for 15 seconds? HOW it actually measures, or computes, the Max Power Point needs to be explained by the manufacturer ...
Some said, it has a shunt and measures only for a few seconds so does not need a huge resistor.
@@OffGridGarageAustralia You can NOT measure Vmp & Imp at the same time with a low ohm shunt. The ohms value of a shunt is way too low to achieve Max Power Point. But, you can use a shunt to easily measure Isc. See my previous, reply just above your reply, regarding my theory of operation using a variable PWM, a very fast MPPT sweep and undersized load ( which you call a shunt ) to determine Max Power Point. Typically, a shunt does not need a "Cool Down" cycle, but an Under-Sized Load will require cooling time. Also, yesterday I wrote, "... HOW this device actually measures, or computes, the Max Power Point needs to be explained by the manufacturer ..."
you damaged the Mosfet in the Batterytester under the CPU cooler ... i replaced it with a new one but i only use it with 150W ..so it works again
One more comment to make sure the polarity of solar panel temperature coefficients are correct.
K*( Real_T - T_stc)
Pmax should go down with increased temperature.
~0.5%/deg_C (0.005)
ISC should go up a little bit with increased temperature.
~ 0.05%/deg_C (0.0005) small enough change to ignore,
so you can use it as a relative solar intensity measuring tool.
VOC should go down with increased temperature.
~0.3 to 0.4%/deg_C (0.004)
~ means approximately
Bei deinem Tester ist der MOSFET kaputt🤔 ich musste den bei mir schon zweimal tauschen da ich zu weit gegangen bin😅 ich habe einen Typ IRFP 260N verbaut. Bei den anderen Tester bin ich schon wirklich gespannt 🙂 Ich nutze für meine Tests einen EBC A20 von ZKE Tech und bin sehr zufrieden. Schöne Grüße
Ist nicht der MOSFET, hab ich getestet.
EBC-A20 kommt im naechsten Video... ;)
I ordered this Tester too. 😁
I use a 300W boost converter with a 10T pot. twister rod glued on pot. screw for easy adj. and a digital power meter cost
Thumbs up and subscribed!
Awesome thank you!
you can get these variable resistors on aliexpress for very reasonable prices, and absolutely massive ones capable of multiple kw. been thinking of buying one myself for testing cells but under very high C rates, for ebike/e-motorbike
I'm really looking into a more reliable and clean solution. When I pick up solar panels, I don't want to setup equipment and find the MPP manually. I'll try this Solar Panel Tester and see how it works.
out of stock .. tried some of them!!! will try next payment
\
Hi Andy, when you end your videos you need too add to "stay safe, stay charged "and stay pissed then you no need to worry if the panels are working or not. Hahahaha
Oh, did I forget that i this video .😂🍺
I had one of those adjustable loads die as well. No evidence as to what failed.
I'll let you know when I found out. I'm in contact with the manufacturer.
Try searching for issues with "delamination" in those particular solar cells.
I checked the panels for that, none of the cells are delaminating.
The tester likely blew a fet!, Maybe it can be repaired by replacement of fet?
Nope, not the FET. It works totally fine.
maybe the power mosfet is fried on the tester with the fan
Yep, I had to replace MOSFET on my unit. My has 20A max current limit.
Mine FET works fine when I tested it. Maybe it plays up when hot?
What was the resistance across a working string on one of your panels where the diode worked correctly and a string that had a failed test on the diode? You can use the Ohms setting on your multimeter to check resistance through the string and diodes. I'm wondering what the resistance measures on the diodes that were showing open in both directions?
Check the Mosfet . I have blown my when trying to draw more than 40 Volt :-)
MOSFET is working fine.
from an old teck pro- High current resistor-Instead.Cheap local version is old hot plate element with exposed nichrome wire then use your alligator clips
i’m curious of what is the resistance on a oven element (you know the thing in spiral which heat your soup), that can take enough current and will not blow if used below 120v.. it’s an idea to explore if you have a spare element somewhere!!
I would need something like 8-10Ohms with 300W
Hi Andy. Why aren't there English subtitles in recent videos ?
No idea, all settings look the same as with other videos.
12 volt light bulb string makes a nice load. Parrelled for 12 volt. Series for higher load.
Better would be to use something above the testing voltage (like 120V/220V bulbs) and add in parallel as needed. A non electronic dimmer could also be used to fine tone it.
Good 💡
I have the same tester with the fan and dials, except mine is 180 watts, and has a different cooler on it, and any time I use it above 1.6 amps, it starts making a weird noise, like one of the circuits is dying.
The manual says 150W/180W but needs a different cooling for 180W. They don't say what needs to be changed though...
They seem to have a fragile circuit design. This is already the second one which died.
@@OffGridGarageAustralia the only difference between yours and mine, is I bought the model with a bigger cooler that has two fans. Doesn't matter how big the cooler is, if I can't have it draw more than 1.6 amps before it starts sounding like a component is dying.
Hot water heater element.
You open the boxes, now you can measure your mc4 connectors (corrosion, full contact)
John might live in USA or UK look for the measurement (Zoll/inches) ;o)
Prost walter
All MC4s are tested fine.
Maybe you can salvage a big resistor from an old e-welding machine (or get one on eBay).
There is a possibility that there is no big/heavy load during the testing, and the battery is fully charged already. What if while trying to run solar panel, connect some big/heavy load (e.g. electric stove/heater/vacuum cleaner/etc...) and check the running current.... Probably there is no problem with the solar panels.... just not enough load to make the high flow of the current.....
Battery is at 60%SOC and can take 5kW from solar.
for a 10 ohm I use a 120v 1200W heater.
Can you try parallel connect to all panel not series at all see different
I've got a 48V battery as you may know.
Battery amps, and volts can give you the wattage into the battery at least...
Recently, I became aware that the DC-AC inverter can be the choke point of how much power we can harness and use. Anybody have a link for an inverter that is more user friendly than 10.5 to 15 V (12volt version)?
Oh the batteries are
LifePo4100ah
GET CHARGED! Or maybe GO CHARGE yourself! Haha, good day!!
Those power load testers require an external power sourse to work properly. I would check your usb cable or power supply before calling it bad.
It would not even turn on without external power supply.
@@OffGridGarageAustralia yet it worked again, after you plugged in after you hooked up a usb battery.
I think you have problem with shading,first.I can suggest to prune the trees little bit,
or you could use half-cut panels that perform better with shade.
I have 8 x 470 Watt half cut panels and I got maximum 3700 watt.I have Hibrid inverter with Mppt controller inside inverter.
I suggest also to try to push more from your panels by applying more load to the system,
to see if you can get more Power.
Other thing is Mppt charger:different Mppt handle Volt & Amp in different ways.
Other thing:you should first power off the Mppt Charger and Inverter before you reconnect the solar panels cables to the system...to avoid to damage Mppt charger and Inverter.
I cannot prune the trees and it would make no sense. This is the situation I have and it will not change.
Half-cell panels may be better but are also more expensive. I've not bought any new panels yet but only these used ones.
Is it possible that the capacity tester died, because the powerbank went off? Most of those newer powerbanks switch off if whatever is connected to them doesnt draw enough current.
In that case the capacity tester has no fan for cooling anymore and also it cannot regulate he voltage and power anymore.
Der schöne große Drahtwiderstand erinnert mich auch an die Schule. Habe vor einiger Zeit mal auf Ebay usw. danach gesucht, aber sowas findet man heute gar nicht mehr.
Einfache Hochlastwiderstande für 100W gibt es aus Ebay allerdings massenweise für ein paar Dollar, z.B auch als Zweierpack mit 20 Ohm. Parallel geschaltet wären das die gesuchten 10Ohm für 200W.
Still had 3/4 of capacity left. The tester stays on, it just stops measuring correctly.
In plain American english, if in full sun clear skys, about noon you measure ISC about 4 amps, and Measure VOC 20% less than VOC @ stc your panel is probably good.
Then if you measure ISC on the roof shortly after and it gives you much less than 4 anps with the clear sky, you have more of a tree? shadow than you realize or the Real panel Temperature is much much higher on the roof than on the ground.
If you measure
We've got lots of large trees around, but they are not the problem. It is very clear that the panels will not perform as well when shaded. That is not the problem.
@@OffGridGarageAustralia read my other comments where I went through the calculation for thermo coefficients.
I can up with an estimate of 130 watts is a representative of a good panel.
Why are we now concentrating on 36.6Voc panels ? The original problem was with 44.5Voc panels.
Three of the former worked fine, the latter did not.
Checking the latest batch of 36.6Voc panels whilst interesting and educational, will not solve the original problem.
The issue remains the charge controller hitting the magic 130v.
I've got different panels with different voltages. Also don't get confused with Voc (45V) and Vmp (36V) with the same panel.
@@OffGridGarageAustralia Not confuse, 51 seconds in 36.97Voc. Original problem panels in episode 6, 2min 50 seconds in, Suntech 45.2Voc and Renesola 44.5Voc.
You stated your new system was 145v and the old 105v, with the new system being the problem.
The charge controller manual says MPTT limit is 130v.
You also had previous problems with the charge controller locking out at 132v, now fixed but how ?
Your new "problem" panels exceed this voltage, so where do you think the problem might be ?
Checking panels at 400 W limit, I have panels as high as 870 W apiece. Sounds too expensive to me.
What panels provide 870 watts?
@@iainkay3630
Sorry I meant to say 370. 😬
@@benjones8977 aha that makes more sense! I’ve got 340-345 watt panels, as they worked out to be the best bang per buck, and keeps panels sized 1.7m x 1.0m.
@@iainkay3630
Yes sometimes I’m just tired & don’t think things through. It was a long hard ordeal to go off grid, I now have 6 kW of PV and 9.6 of lithium batteries.
Being somebody who didn’t know a thing about electricity, it’s nice to know if you have an interest you can achieve it!
@@benjones8977 that is really good work!
I’m not going to be in this property long enough to take it off grid but want to run my PV and Battery set up alongside it parallel to reduce my environmental impact and bills - all whilst doing the set up in a relatively easy to remove fashion.
I just found the Elejoy WS400A for about 74 Australian dollar
That's what I paid at AliExpress...
Carbon Pile load tester .
ws400a
Your a teaser 😁
👍👍👍
, 😊👍 Hello
Hello 😊
Please say "pi" not raspi... You make us tech heads cringe..
Call it what you like 🤪
Sorry but I find it rude for you to tell him how to speak on his channel . Some peoples children.
Hy Andy, might not be the problem your second solar charger is not s with
s
becomming slave of the first charger (master) of different software level. So it does not see the battery voltage but the master voltage and reduces the aps.
62th ;-)
Sticker -> ✨
Shop talk is good for de-stressing lol