Solar The Solar Panel Thread

[Boots in Action]

I can show you how to catch Flathead but it may be my fish of the century, you know the one fish you catch.............I look in the boot of Big Mal at the new charging panel set up I made looks very cool and at the new harness for the double batteries all made up ,along with the new battery box for the second battery, all ready to go, just need to add the battery and hook it all up....one day. All the gear all made up and ready just in case I come across a not to be missed battery deal when on the road I don't have to wait, it's ready to go.......Battery, Heater, Boat oh so many toys so little money.........(actually none of the latter)

@Drover , speaking of power hook ups from outside, I have been able to attach 2 Anderson plugs to bottom of chassis to enable easy connection of solar panels with wiring going straight to the one MPPT controller. Easy connect and disconnect at all times with cover for protection against dirt and the elements. The other one is for direct charging to battery (with 20A inline fuse) for use whenever I can get to use my 7 stage "smart" charger which is superior to the Setec unit as I have said in previous threads. I used adhesive labeling to ensure clearly marked. Once again, very east connecting/disconnecting as I have an Anderson plug on end of charger ( and another lead with Anderson plug on one end and alligator clips on the other to use if necessary). No more scrambling around under beds to connect to battery. Very useful and versatile. See photo.

 

[Drover]

Yep @Boots in Action thats really the only way to go, though my portable I have the controller still on it as it can then be plugged into the ute or van and the anderson plugs can be used for other things as well, when I upgrade the ute's system I may run dedicated andersons for the panel to the van and ute controllers in the fullness of time, on Big Mal the fridge power cable on the draw bar has an anderson at the fridge so when camped it can actually be used as an extension lead, the plug on the draw bar can be plugged into the battery anderson and the solar panel if mounted at the rear of Big Mal can be plugged into the anderson at the fridge,bIg Mal is 22 ft so it does save a bit of extra wiring, the cable is 6 B&S , don't use it that way much but it is an option even for compressor and stuff....hate to think how much the original owner paid for it to be done.

 

[Boots in Action]

Look forward to your test results, always like real world testing they seem to give a better picture than bench or magazine tests.........my Pro Star seems to do a good job,your results @Boots in Action I might be able to see if it's worth the money to upgrade to a MPPT unit now that I've redone all the connections.....

Hi there @Drover , @mikerezny , @Crusty181 and other members who have been following the discussions on solar panels/hook ups and MPPT controllers. As promised, I have done an extensive field test over the last few days whilst away. The following data will give you something to interpret and think about. And no @Drover , it will not be too complicated for you to understand! I endeavored to eliminate or at least reduce as many variables as possible, so have included a lot of parameters that could/may have distorted the results. I do not want to mislead anybody.
The tests were carried out on two days Monday 24th and Wednesday 26th July between the hours of 10.30 and 10.55am in Connondale Ranges.
The weather was perfect - fine, sunny and clear cloudless skies. Sunny Queensland at its best!!
The mornings were cold around 3C, but temp at time of testing was around 20C.
Battery temp was only 11C at time of testing - rather low for output! Battery was 120Ah AGM.
The MPPT solar controller was a LD 30A Dreamtime Series which I bought on Ebay for around $140.
3 panels were used: "A" - 80w, "B" - 180w and "C" a 200w. Outputs as advertised by manufactures not necessarily correct - see test results!
All panels were placed in optimal positions facing north with no shading at all, AND WERE NOT MOVED DURING TESTING.
A 4 to 5 amp draw was placed on battery for at least 3 to 4 hours before testing to reduce battery voltage, and remained ON during all tests.
Battery voltage at start of testing was down to 12.2 volts under the 4 to 5 amp load.

INDIVIDUAL PANEL TESTING Panel A Panel B Panel C
OPEN CIRCUIT VOLTAGE 21 volts 21.6 volts 19.1 volts
BATTERY VOLTAGE 12.8 13.1 13.2 SOLAR PANEL CHARGE VOLTAGE 16.2 15.9 14.7
CHARGING CURRENT 6.0 A ( 76.8 watts *) 9.2 A (120.5 watts) 8.3 A (109.5 watts)
LOAD 3.9 A 4.2 A 4.3 A

PARALLEL HOOK UP RESULTS SERIES HOOK UP RESULTS
''A'' PLUS ''B'
BATTERY VOLTAGE 13.4 volts 13.4 volts
SOLAR CHARGE VOLTAGE 15.0 volts 32.0 volts
CHARGING CURRENT 13.2 A (176.8 watts) 11.8 A (158.1 watts)
LOAD 4.5 A 4.5 A

''B" PLUS "C"
BATTERY VOLTAGE 13.7 volts 13.8 volts
SOLAR CHARGE VOLTAGE 15.2 volts 28.4 volts
CHARGING CURRENT 12.8 A (175.3 watts) 15.8 A (218.0 watts)
LOAD 4.7 A 4.8 A

"A" PLUS "C"
BATTERY VOLTAGE 13.6 volts 13.6 volts
SOLAR CHARGE VOLTAGE 15.1 volts 29.8 volts
CHARGING CURRENT 10.6 A (144.1 watts) 10.9 A (148.2 watts)
LOAD 4.6 A 4.6 A

So there you have it!! A lot of figures to wade through. There is NO doubt whatsoever that an proper MPPT solar controller is way ahead of PWM types, particularly if panels are connected in SERIES. The first test on the Monday produced similar results, only marginally less because I had not discharged the battery to as low a voltage as on the Wednesday test.
NOTE: These tests were conducted under what I call nearly perfect conditions for all tests. Some figures I could not believe, so did readings several times to be sure I had the correct figures. All figures were provided on my solar controller except where I had to use my own multimeter eg OCV, load voltage at panels whilst panels were in operation.
"*" The figures for this panel "A" which was rated at only 4.5 A max current output produced a reading of 6.0A EVERY time tested, proving how efficient my MPPT solar controller is. That is a gain of 33% on original output!!! Gains of at least 20 to 25% can be seen on the readings above. The MPPT tracking was very fast every time I changed the combinations and panel hook ups.
And no, I am not trying to sell my brand of MPPT controller, but I can say that it does a great job for me!!

End of this epistle!! Questions and comments are invited.

 

[G Daddy]

@Boots in Action Very Interesting Test well done, i presume the charging current is measured entering the battery not the current from the solar panels.
Did you measure the current from the panels?
If the current is measured into the batteries is the calculated wattage into the batteries ( in A plus C ) would be 10.6A ( 144.16 ) 10.9A ( 148.24),
is that correct or am I reading your figures wrong

 

[Boots in Action]

@Boots in Action Very Interesting Test well done, i presume the charging current is measured entering the battery not the current from the solar panels.
Did you measure the current from the panels?
If the current is measured into the batteries is the calculated wattage into the batteries ( in A plus C ) would be 10.6A ( 14416 ) 10.9A ( 148.24),
is that correct or am I reading your figures wrong

Hi @G Daddy, thanks for the compliment. Unfortunately, although I set out the figures ACROSS the page in COLUMNS so it was easy to read and compare, what it turned out as received makes it a bit more difficult to interpret and compare. Sorry about that!!

In answer to your questions: All figures regarding current and panel input voltage were taken from readings on the output side of the controller as entering battery. I did not do a current check from the panels before entering solar controller, although I did do a check of INDIVIDUAL panel outputs at beginning of testing. See chart. Seems like a very efficient DC to DC system with hardly any losses internally.

In the tests for "A" plus "C" , input voltage of 15.1v multiplied by current of 10.6A works out at 160 watts (parallel connection). Series connection of 29.8 volts multiplied by current of 10.9A comes to 324.8 watts as per the chart. Amazing how much difference higher voltage makes to output, not to mention a lot less loss in cabling between panel and controller.

I forgot to mention ALL connections were Anderson plug to Anderson plug to prevent any losses. Also, no noticeable heat buildup in controller, even though it has a temperature sensor in it set at 75C and also a battery temp sensor for battery charging compensation. I extended the short cable with the thermister and taped it to the top of the AGM battery under the battery cover. With a battery temp of only 11C, the acceptable charge voltage for the AGM would have been as high as 15 volts, according to the charts I have placed in this forum.
Hope this helps. Thanks for checking. I will send photos of "solar farm" testing setup shortly. Cheers

 

[G Daddy]

Hi @Boots in Action thanks for your reply, my understanding is wattage into the battery is volts multiplied by amps,
so 10.6 A x 13.6V = 144.16 Watts and 10.9A x 13.6V = 148.24 Watts

 

[mikerezny]

Hi @Boots in Action thanks for your reply, my understanding is wattage into the battery is volts multiplied by amps,
so 10.6 A x 13.6V = 144.16 Watts and 10.9A x 13.6V = 148.24 Watts

Hi @GDaddy,
I agree with your figures for A and C. The wattage being delivered into the battery is the BATTERY voltage, 13.6V in both series and parallel connection multiplied by the current into the batteries, 10.6A in the parallel test and 10.9A in the series test.
Which gives 144.16W for the parallel test and 148.24W for the series test. This would indicate that there is an increased efficiency of about 2.8% for the series connection over the parallel connection.

Looking at the figures for A and B, the output current actually goes down quite a bit from 13.2A down to 11.8A. In this case, the parallel connection delivers substantially more power.

For the case of B and C, there is a significant improvement with the series connection, from 12.8A up to 15.8A.

Hi @Boots in Action, do you agree with these conclusions?

cheers
Mike

 

[G Daddy]

Hi @Boots in Action ,Yes agree with that. I need to look at the results a bit more for the B and C case because the parallel look low. In the singe; test B was putting out 9.2A and C 8.3A, just in parallel only 12.8A does not look right

 

[Boots in Action]

Hi @GDaddy,
I agree with your figures for A and C. The wattage being delivered into the battery is the BATTERY voltage, 13.6V in both series and parallel connection multiplied by the current into the batteries, 10.6A in the parallel test and 10.9A in the series test.
Which gives 144.16W for the parallel test and 148.24W for the series test. This would indicate that there is an increased efficiency of about 2.8% for the series connection over the parallel connection.

Looking at the figures for A and B, the output current actually goes down quite a bit from 13.2A down to 11.8A. In this case, the parallel connection delivers substantially more power.

For the case of B and C, there is a significant improvement with the series connection, from 12.8A up to 15.8A.

Hi @Boots in Action, do you agree with these conclusions?

cheers
Mike

Hi @mikerezny and @G Daddy, whoops!! Seems I got carried away with some of those figures believing that all those watts were available for the battery, but forgetting that the higher voltages had already been converted into higher amps by the MPPT controller . I guess that I was thinking that to charge a battery which was at only 12.6 volts, you would have to have a much higher voltage to overcome the resistance of the internals in the battery ie. to charge a battery from 12.6 volts, you would need to apply a much higher voltage, say up to 13 volts or higher to get any amps into the battery. Took the ALT E Utube video as a guide as what was available to charge battery!!

There were some interesting anomalies as you can see. The so called battery "C" rated at 200w failed to reach any higher current output than 8.3A , at panel voltage of 14.7v and 13.2v for battery voltage, load was 4.3A. OCV was only 19.1v too. The output on the Monday test was lower - only 7.3A at same panel voltage and battery voltage, whilst load was lesser at 4A. I guess that as the OCV was the lowest, it must have affected the final result, EXCEPT "B" plus "C'" where there seemed to be a better match?? Solar panel quality and output???? Battery output for battery "B" (180w) on Monday was also down at only 8.6A, panel voltage was 14.9v and load at just 4A. However battery voltage was the same at 13.1v!!!
When looking at "A" plus "B", I think it is the large mismatch of panel output wattage that is causing the big drop off in amperage, just as in the videos on Utube - only 80w against 180w. - although OCV is 21v and 21.6v respectively. Lots more to think about. Thanks for the correction too!
Cheers

 

[Drover]

I'm here, just busy, will print it all out so my head doesn't spin and my aging grey matter can work out whats, what.....might be easier to just read the comments....................reminds of my Maths classes when my eyes would roll into the back of my head in algebra..............I need to draw pictures...lol.

 

[Boots in Action]

Hi @Boots in Action ,Yes agree with that. I need to look at the results a bit more for the B and C case because the parallel look low. In the singe; test B was putting out 9.2A and C 8.3A, just in parallel only 12.8A does not look right

Hello again @G Daddy , you seem to be able to interpret all the data pretty well and have no doubt noticed some of the anomalies that have come up. I rechecked ALL the data for the Wednesday test (as listed on original chart- amended!) with the readings for the Monday test which I have not shown. However, the figures are basically the same with the same anomalies as in Wednesday's test. So that rules out any error in transfer data!! In hindsight, I should have shown the Vpm (voltage power maximum) for each panel as that may be one of the reasons of incompatibility of panel outputs. "A" rated at 80 watts is 17.6 volts Vmp and when multiplied by max power current (Ipm) 4.55A comes to 80.0 watts - correct. "B" rated at 180 watts, 18.0 volts by 10.01 comes to 180 watts - correct. "C" panel rated at 200 watts, 18.3 volts by 10.92A comes to 199.83 watts - close enough!!! Could it be that the different Vpm for each panel has a bearing on connected panel outputs?? I did do a check on panel output voltages whilst they were under load, but I do not remember any major differences - perhaps 17 volts for "A", and 18 volts for both "B" and "C". Yet this is not shown at PV figures in chart. See figures in chart which were taken from MPPT screen while testing which did not come anywhere near 36 volts except "A" plus "B" series test. Looks like more testing required to solve this!!
Any ideas on "Why is it so"??? @mikerezny , can you provide some input on this also??

 

[G Daddy]

Hi @Boots in Action , still trying to analyze the numbers for the B and C case to figure out where there could be a problem
Cheers

 

[Boots in Action]

I'm here, just busy, will print it all out so my head doesn't spin and my aging grey matter can work out whats, what.....might be easier to just read the comments....................reminds of my Maths classes when my eyes would roll into the back of my head in algebra..............I need to draw pictures...lol.

Hi @Drover , take your time as there appears to be some issues which need further explanation and investigation - and more testing looking at some other details. At this stage, I too am doing more research on my MPPT solar controller which says it has "PV array limited input function, to ensure that the controller does not overload operation under any conditions". @G Daddy and @ Mikerezny are tech electrical gurus who are assisting me at this moment. Others with more info hopefully will come forward.
Looks like we may be on to something for @aspiremr . If only we were "on the spot", I agree we could fix it in just a few seconds with a multimeter. Instead, we are doing "remote instruction" from afar.!!!
And don't let your eyes roll back too far when looking at my figures. They may stay that way if the wind changes!!! Cheers

 

[mikerezny]

Hi @Boots in Action,
silly question, but ...
1: do all three of your panels have blocking diodes? This is necessary for your parallel tests to avoid a situation where one panel is not as much in the sun as one of the other panels. In such a case, without blocking diodes, the panel not pulling its weight will become a load and not a source. A blocking diode is wired in series in each panel. Another use of a blocking diode is if the panel is connected directly to a battery. When there is no sunlight, the panel will be a load and discharge the battery. This is not a problem if one has a solar regulator since it will perform the blocking function. But a solar controller will not solve the problem of one panel discharging into the other.

2: did all of your panels have bypass diodes? This is necessary when wiring panels in series to allow a panel that is not in the sun to be bypassed. In the two panel case, if one panel is not in the sun, the bypass diode will allow the other panel to deliver to the solar regulator, albeit at half the voltage.

I have attached a diagram showing the details.

Now, if one has blocking diodes, I think there is a potential problem connecting solar panels in parallel when they have substantially different voltages.
Two types of diodes are available as bypass diodes in solar panels and arrays: the PN-junction silicon diode and the Schottky barrier diode. Both are available with a wide range of current ratings. The Schottky barrier diode has a much lower forward voltage drop of about 0.4 volts as opposed to the PN diodes 0.7 volt drop for a silicon device.

Assuming Schottky diodes are used with a voltage drop of 0.4V.
Now assume one panel has a Vmax of 18.6V and another panel has a Voc of 18.0V. If the MPPT controller chooses to load the panels at 19.0V (18.6V + 0.4V across the diode) and the first panel will be working optimally, BUT the second panel, with an open circuit voltage of only 18.0V, would need to deliver 18.6V before it could contribute and this cannot happen in this situation.
If I am correct, then a PWM controller might well deliver better performance since it loads both cells to not much more than the battery voltage and thus both cells would always contribute.

If I were faced with a situation of having two solar cells with quite different voltages, I would wire them in parallel and use a single PWM controller, OR use two MPPT controllers if this was cost effective compared to the solar panels, OR, if the cells also had a substantial difference in wattage, use a MPPT controller for the panel with a higher output and a cheap PWM controller for the smaller panel, OR, obtain two identical panels, wire them in series or parallel and use a good MPPT controller.

This is getting way too complicated and is really violating the KISS principle which I try to adhere to.

cheers
Mike

 

[Boots in Action]

Hi @Boots in Action,
silly question, but ...
1: do all three of your panels have blocking diodes? This is necessary for your parallel tests to avoid a situation where one panel is not as much in the sun as one of the other panels. In such a case, without blocking diodes, the panel not pulling its weight will become a load and not a source. A blocking diode is wired in series in each panel. Another use of a blocking diode is if the panel is connected directly to a battery. When there is no sunlight, the panel will be a load and discharge the battery. This is not a problem if one has a solar regulator since it will perform the blocking function. But a solar controller will not solve the problem of one panel discharging into the other.

2: did all of your panels have bypass diodes? This is necessary when wiring panels in series to allow a panel that is not in the sun to be bypassed. In the two panel case, if one panel is not in the sun, the bypass diode will allow the other panel to deliver to the solar regulator, albeit at half the voltage.

I have attached a diagram showing the details.

View attachment 56204


Now, if one has blocking diodes, I think there is a potential problem connecting solar panels in parallel when they have substantially different voltages.
Two types of diodes are available as bypass diodes in solar panels and arrays: the PN-junction silicon diode and the Schottky barrier diode. Both are available with a wide range of current ratings. The Schottky barrier diode has a much lower forward voltage drop of about 0.4 volts as opposed to the PN diodes 0.7 volt drop for a silicon device.

Assuming Schottky diodes are used with a voltage drop of 0.4V.
Now assume one panel has a Vmax of 18.6V and another panel has a Voc of 18.0V. If the MPPT controller chooses to load the panels at 19.0V (18.6V + 0.4V across the diode) and the first panel will be working optimally, BUT the second panel, with an open circuit voltage of only 18.0V, would need to deliver 18.6V before it could contribute and this cannot happen in this situation.
If I am correct, then a PWM controller might well deliver better performance since it loads both cells to not much more than the battery voltage and thus both cells would always contribute.

If I were faced with a situation of having two solar cells with quite different voltages, I would wire them in parallel and use a single PWM controller, OR use two MPPT controllers if this was cost effective compared to the solar panels, OR, if the cells also had a substantial difference in wattage, use a MPPT controller for the panel with a higher output and a cheap PWM controller for the smaller panel, OR, obtain two identical panels, wire them in series or parallel and use a good MPPT controller.

This is getting way too complicated and is really violating the KISS principle which I try to adhere to.

cheers
Mike

Well thank you @mikerezny for THAT INFORMATION. Now we are really getting technical !!!. But I am up to it and with you all the way. Let me set out the advertised/tested Ocv and Vmp for each panel and let you see if you can discover the weakness in the setup.
Firstly, ALL panels were set up in FULL direct sunshine - cloudless skies for full tests and NOT moved throughout testing.
Secondly, data for all three panels is as follows.
80 watt (panel "A") : Voc is 21.6 V, Vpm is 17.6 V, Ipm is 4.55 A .
180 watt (panel "B") : Voc is 22.5 V, Vpm is 18.0 V, Ipm is 10.01 A.
200 watt (panel "C") : Voc is 19.1 V, Vmp is 18.3 V, Ipm is 10.92 A.

In test with "A" plus "B", Parallel was better output than Series by nearly 1.5 Amps .- refer test data.
In test with "B" plus "C", Series was better output than Parallel by 3.0 Amps - refer test data.
In test with "A" plus "C", Series was just 0.3 Amp better than Parallel on Wednesday tests, but there was at least 1.0 Amp more output in Series than in Parallel on Monday tests and battery voltage was the same at 13.6 Volts.

As far as the diodes are concerned, I believe that all are blocking diode type in each panel, BUT I will get them out tomorrow to check and will test EACH diode with my best multimeter and report back to you. Fantastic electronic info there @mikerezny which will give me something to work on. I do not want to buy another MPPT controller as the latest one just fits inside where I can see it properly, and there is now no extra room to re-install my old PWM controller. If the PN silicon diodes are causing too much voltage drop (at .6 v per diode in series), I could get some Schottky diodes to replace them and see how output changes. As I am getting 15.8 Amps with the "B" plus "C" setup, I am reasonably satisfied, but always looking for the most optimum connections where ever possible!! And at minimum cost too!!

There ARE some TECHNICAL GURUS out there after all!! Great work and thanks again. By the way, where did you get such in depth technical knowledge?? I did pretty well in High School in Physics and Chemistry and had more than 35 years in the Army Reserve Artillery Corps with a lot of it in the communication field. Retired in Dec 1999 with the rank of WO2. Unfortunately, did not get into really tech stuff but had to teach a lot of theory and do a lot of field repair work. Now, onward with the testing............

 

[mikerezny]

There ARE some TECHNICAL GURUS out there after all!! Great work and thanks again. By the way, where did you get such in depth technical knowledge?? I did pretty well in High School in Physics and Chemistry and had more than 35 years in the Army Reserve Artillery Corps with a lot of it in the communication field. Retired in Dec 1999 with the rank of WO2. Unfortunately, did not get into really tech stuff but had to teach a lot of theory and do a lot of field repair work.

Hi @Boots in Action,
I have been into electronics one way or another since grade 5, over 50 years ago. PMG, servicing Radios and TV, HiFi enthusiast, Professional Audio and Video, and for the last 20 or so years working with super computers in the area of Climate and Weather modelling. I was always good at Mathematics and that made it easy for me to learn Physics, Chemistry, Electronics, and Programming. This year I have pretty much retired but I am still active in parts of my old jobs in those areas that I find interesting.

In my early days when I was 17 or so, I had a beautiful FJ Holden. But it was a 6V system and I wanted to have a 12V radio. So I completely converted the FJ from 6V to 12V using all the bits from later Holdens. That was where I probably got my initial experience with playing with 12V car bits.

When I was 15, I was in the Air Cadets and only a cats whisker away from joining the RAAF as a radio tech. Passed the medical and all set to go. Got cold feet and pulled the pin at the last minute. In hindsight, I am not sure I would have coped with RAAF discipline in my early years. I have always needed to respect the people I have to report to.

By the way, I was born in Brisbane and spent most of my life in Brisbane or Maryborough. Shifted to Melbourne about 20 years ago.

best wishes
Mike

 

[G Daddy]

Hi @Boots in Action I think @mikerezny is talking about extra blocking diodes between each panel, which is used to offset the effects of shading on one panel in multiple panel setups. As a matter of interest there are new panels coming out shortly with blocking diodes on each cell in a panel to improve efficiency in varying shade conditions.

 

[Boots in Action]

Hi @Boots in Action,
I have been into electronics one way or another since grade 5, over 50 years ago. PMG, servicing Radios and TV, HiFi enthusiast, Professional Audio and Video, and for the last 20 or so years working with super computers in the area of Climate and Weather modelling. I was always good at Mathematics and that made it easy for me to learn Physics, Chemistry, Electronics, and Programming. This year I have pretty much retired but I am still active in parts of my old jobs in those areas that I find interesting.

In my early days when I was 17 or so, I had a beautiful FJ Holden. But it was a 6V system and I wanted to have a 12V radio. So I completely converted the FJ from 6V to 12V using all the bits from later Holdens. That was where I probably got my initial experience with playing with 12V car bits.

When I was 15, I was in the Air Cadets and only a cats whisker away from joining the RAAF as a radio tech. Passed the medical and all set to go. Got cold feet and pulled the pin at the last minute. In hindsight, I am not sure I would have coped with RAAF discipline in my early years. I have always needed to respect the people I have to report to.

By the way, I was born in Brisbane and spent most of my life in Brisbane or Maryborough. Shifted to Melbourne about 20 years ago.

best wishes
Mike

Hi @mikerezny , congratulations. I dips my lid to your greater knowledge!! You are a great asset to have on a forum like this. I too like the KISS principal and try to explain things simply for those who have limited electric knowledge. When I was in a car club, there were members who could rebuild all engines and feel/notice bearing/journals that were out of round by only 10 thou. But mention car electrics, they immediately shied away calling it "white man magic" because they could not actually see the electric currents and voltages. To each his own in expertise!!!

 

[mikerezny]

Hi @Boots in Action As a matter of interest there are new panels coming out shortly with blocking diodes on each cell in a panel to improve efficiency in varying shade conditions.

Hi @G Daddy,
thanks, that is really useful information.

Since we like to park in shade, I spend more time then I would like, shifting the solar panel around because of a tiny shadow drifting onto the panel resulting in zero output.So I would be interested in replacing my panel with one of the ones you mentioned.

You have just reminded me that I need to go buy some more cable to extend the radius around my van so I can get the panel further away and into less shaded areas.

cheers
Mike

 

[Boots in Action]

Hi @Boots in Action I think @mikerezny is talking about extra blocking diodes between each panel, which is used to offset the effects of shading on one panel in multiple panel setups. As a matter of interest there are new panels coming out shortly with blocking diodes on each cell in a panel to improve efficiency in varying shade conditions.

Thanks @G Daddy for clarifying that about Blocking diodes . If that is what @mikerezny is referring to, then it will be an easy fix to insert a Schottky diode in the output line of one of the panels that connects in series with the other panel. More great information. Another good reason for being on this forum - knowledgeable and friendly members! Cheers