Solar The Solar Panel Thread

[Crusty181]

60 pages in this thread and my life is to short to read back through it all. so ... ok Fairy God Helpers.

We've been relying on the factory single 150w for a long time. I wanted to upgrade by the market is a minefield of underpriced underperforming crap, and ridiculously overpriced alternatives neither I have much interest in. I did try a while back to upgrade but the annoying random quality was an issue only matched by the annoying ridiculous costs of so-called quality panels, so I lost all interest at buying both cheap $hit that didn't work or expensive overrated panels I needed to sell my firstborn to pay for ... so I just put up with the 2 x blankets I already have. If solar doesn't work or costs more than a generator (which provides real proper power) then solar is rubbish ... anyway, I'm green now and I've moved on from proper power

Fast forward to now and I have just had delivered 3 x 200w panels; 200s because of their extraordinarily convenient physical size. One will swap out directly into the existing 150w panel brackets positioned across the rear of the van roof. The other two panels will slot in very neatly just in front of the rear panel but running along each side of the roof between the roof edge and the aircon .... all very neat and not impacting on the aircon or the J Mould The wiring will also be short between the panels which is another bonus. I will run the wiring through a conduit between the panel frames to keep wiring off the roof surface and stop any cabling interfering with rainwater runoff.

The original solar roof junction box is located under the existing 150w, so it will stay put be under the new 200w. I'll cut the 150w cabling at the panel terminal box and add MC4 connectors to them. This will make the wiring of the 3 panels quite short and simple, all with the MC4 connectors. I'm wiring the panels in series and have already had the required voltage and amperage happy MPPT controller in the van for some time. All the wiring and terminals will be protected from the UV either in the conduit or under the rear panel. Cutting the cabling off the 150w panel and adding the MC4 connectors means I don't have to touch the roof solar junction box at all, so quick check of its waterproofing and move on.

I'm assuming the new panels will likely have blocking diodes is it advisable or even necessary to swap these out for bypass diodes.

Anything you see here that poses an issue, or should be avoided, or you'd like to watch catch on fire, jump in let me know.

 

[Boots in Action]

60 pages in this thread and my life is to short to read back through it all. so ... ok Fairy God Helpers.

We've been relying on the factory single 150w for a long time. I wanted to upgrade by the market is a minefield of underpriced underperforming crap, and ridiculously overpriced alternatives neither I have much interest in. I did try a while back to upgrade but the annoying random quality was an issue only matched by the annoying ridiculous costs of so-called quality panels, so I lost all interest at buying both cheap $hit that didn't work or expensive overrated panels I needed to sell my firstborn to pay for ... so I just put up with the 2 x blankets I already have. If solar doesn't work or costs more than a generator (which provides real proper power) then solar is rubbish ... anyway, I'm green now and I've moved on from proper power

Fast forward to now and I have just had delivered 3 x 200w panels; 200s because of their extraordinarily convenient physical size. One will swap out directly into the existing 150w panel brackets positioned across the rear of the van roof. The other two panels will slot in very neatly just in front of the rear panel but running along each side of the roof between the roof edge and the aircon .... all very neat and not impacting on the aircon or the J Mould The wiring will also be short between the panels which is another bonus. I will run the wiring through a conduit between the panel frames to keep wiring off the roof surface and stop any cabling interfering with rainwater runoff.

The original solar roof junction box is located under the existing 150w, so it will stay put be under the new 200w. I'll cut the 150w cabling at the panel terminal box and add MC4 connectors to them. This will make the wiring of the 3 panels quite short and simple, all with the MC4 connectors. I'm wiring the panels in series and have already had the required voltage and amperage happy MPPT controller in the van for some time. All the wiring and terminals will be protected from the UV either in the conduit or under the rear panel. Cutting the cabling off the 150w panel and adding the MC4 connectors means I don't have to touch the roof solar junction box at all, so quick check of its waterproofing and move on.

I'm assuming the new panels will likely have blocking diodes is it advisable or even necessary to swap these out for bypass diodes.

Anything you see here that poses an issue, or should be avoided, or you'd like to watch catch on fire, jump in let me know.

Well @Crusty181 , you set the bait and you knew I would respond, didn't you?? It just so happens that I was about to provide some realistic details from a very recent field test with my equipment involving my MPPT controller with 3 panels in series. I too have been rather skeptical on how panel outputs are rated, but recently got sucked into purchasing a 200w folding solar panel rated at 23% efficient, at a special delivered cost of $113.50 - special rate for a month. Supposed German panels, so I decided to give it a go. Yes, the PWM with it controller was basic, but as mine are all bypassed, it was not a problem. This added to my existing panels - 1 X 180w @17%efficiency) and the other a 200w also at 17%. I found that each was rated at 22.5v open circuit voltage and 18.0v max working voltage. My tests of each individual panel confirmed the ocv, but the working voltage with Schottky 15A 60V diodes gave me 18.3 volts on each. I had changed all the bypass diodes from the 1000v 10A Barrier type, as the Schotty diodes has less forward voltage drop. Whilst my MPPT controller was only rated at 30A , it can handle up to 100 volts. Also, as there is never going to be 15A going through the Schottky diodes whilst panels are in series (max which I have seen was a bit over 8 amps under really good conditions for any of the panels!!), I believed the MPPT controller could handle these figures.
Just to show how much an MPPT controller can produce with panels in series under poor light conditions late in the day, I took careful note of the following test figures.
The total current going into the controller was measured with my clamp meter at 1.38A, bearing in mind that this low amount was limited to the output of the least efficient panel . The panel voltage as shown on MPPT controller was 55 volts. Input into battery was 5.3 amps when battery voltage as shown on controller was 13.3 volts. A light load of 1.8 amps was showing on controller for running fans in fridges. So when light is low or conditions are varying, an MPPT controller can generate power by using the higher voltage. In my case, I doubt if the 3 panels in Parallel could have made a total of 2 amps at best and probably less!! Another test I recorded was under better (but far from ideal!) conditions and the input from panels (once again measured with my clamp meter) was 5.8 amps. The controller showed that panel voltage was 48 volts and the charge current into battery was more than 21 amps with battery voltage of 13.0 volts. So the system DOES work .

However, with all good things, there are some drawbacks. Firstly, one must have the $$$s to have this number of panels and each one weighs approx 12 kgs. Then there is the wiring which tends to be straight forward to connect with Anderson plugs, but easily gets into a mess if tangled. You have to have a single pos wire connecting to the neg on the next panel and so on connecting all panels and yet two wires must run back to connection on van and thence to controller. Fortunately, the wire does not have to be all that heavy when working at higher voltages. All my panels are portable so I can follow the sun for max generation. Then if one panel (there are two panels on folding types) or part thereof is shaded, you lose the power from that panel and have to rely on the bypass diodes to carry the current around that panel. My folding panels have two bypass diodes (Schottky), one for each part of the folding panel. The MPPT controller provides the blocking diodes to prevent current leaking back through panels at night or when no power is being produced by panels.
So @Crusty181 , you do not have to worry about Blocking diodes as your controller has that built in, but you should get less forward voltage drop with Schottky diodes. However, with your roof panels, which I understand are all one unit (not two haves as in folding type), any shade is going to affect the whole array when panels are in series as the bypass diodes for each panel are all in series with any generated current. This situation would also occur if BOTH parts of one of my folding panels was shaded. So my situation is less critical. All the above is only my own understanding of solar, but has been backed up with actual field conditions in strict recorded testing. Good luck, and I hope this is helpful to you.

 

[Boots in Action]

Well @Crusty181 , you set the bait and you knew I would respond, didn't you?? It just so happens that I was about to provide some realistic details from a very recent field test with my equipment involving my MPPT controller with 3 panels in series. I too have been rather skeptical on how panel outputs are rated, but recently got sucked into purchasing a 200w folding solar panel rated at 23% efficient, at a special delivered cost of $113.50 - special rate for a month. Supposed German panels, so I decided to give it a go. Yes, the PWM with it controller was basic, but as mine are all bypassed, it was not a problem. This added to my existing panels - 1 X 180w @17%efficiency) and the other a 200w also at 17%. I found that each was rated at 22.5v open circuit voltage and 18.0v max working voltage. My tests of each individual panel confirmed the ocv, but the working voltage with Schottky 15A 60V diodes gave me 18.3 volts on each. I had changed all the bypass diodes from the 1000v 10A Barrier type, as the Schotty diodes has less forward voltage drop. Whilst my MPPT controller was only rated at 30A , it can handle up to 100 volts. Also, as there is never going to be 15A going through the Schottky diodes whilst panels are in series (max which I have seen was a bit over 8 amps under really good conditions for any of the panels!!), I believed the MPPT controller could handle these figures.
Just to show how much an MPPT controller can produce with panels in series under poor light conditions late in the day, I took careful note of the following test figures.
The total current going into the controller was measured with my clamp meter at 1.38A, , bearing in mind that this low amount was limited to the output of the least efficient panel . The panel voltage as shown on MPPT controller was 55 volts. Input into battery was 5.3 amps when battery voltage as shown on controller was 13.3 volts. A light load of 1.8 amps was showing on controller for running fans in fridges. So when light is low or conditions are varying, an MPPT controller can generate power by using the higher voltage. In my case, I doubt if the 3 panels in Parallel could have made a total of 2 amps at best and probably less!! Another test I recorded was under better (but far from ideal!) conditions and the input from panels (once again measured with my clamp meter) was 5.8 amps. The controller showed that panel voltage was 48 volts and the charge current into battery was more than 21 amps with battery voltage of 13.0 volts. So the system DOES work .

However, with all good things, there are some drawbacks. Firstly, one must have the $$$s to have this number of panels and each one weighs approx 12 kgs. Then there is the wiring which tends to be straight forward to connect with Anderson plugs, but easily gets into a mess if tangled. You have to have a single pos wire connecting to the neg on the next panel and so on connecting all panels and yet two wires must run back to connection on van and thence to controller. Fortunately, the wire does not have to be all that heavy when working at higher voltages. All my panels are portable so I can follow the sun for max generation. Then if one panel (there are two panels on folding types) or part thereof is shaded, you lose the power from that panel and have to rely on the bypass diodes to carry the current around that panel. My folding panels have two bypass diodes (Schottky), one for each part of the folding panel. The MPPT controller provides the blocking diodes to prevent current leaking back through panels at night or when no power is being produced by panels.
So @Crusty181 , you do not have to worry about Blocking diodes as your controller has that built in, but you should get less forward voltage drop with Schottky diodes. However, with your roof panels, which I understand are all one unit (not two haves as in folding type), any shade is going to affect the whole array when panels are in series as the bypass diodes for each panel are all in series with any generated current. This situation would also occur if BOTH parts of one of my folding panels was shaded. So my situation is less critical. All the above is only my own understanding of solar, but has been backed up with actual field conditions in strict recorded testing. Good luck, and I hope this is helpful to you.

Hi there again @Crusty181 , I was just about to put my head down when I had a thought about how you can reduce the possibility of having shade (on one or more, but not all of your three panels connected in series) affect the output. All you have to do is place a bypass diode in parallel with each panel so that if one or even two panels are shaded, current generated from the non shaded panel/s can flow around the shaded panel/s. Suggest using Schottky diode 15A 60V type which will cost you approx $ 4.00 for a pack of 10 on Ebay. Connect the diode between the neg and pos outputs of each panel noting polarity of diode as it will only pass current one way. The neg is the end with white band and the other end is pos. Positive current will not flow back across the white line. Not sure what is in the junction box of single panels. It may already have diodes there depending on how the number if individual solar cells are connected up. A picture showing connection/s and diode type would help clarify that BEFORE doing anything!!

 

[Crusty181]

You only have to ask, and you shall receive Sir.

I presume the bypass diode x 2 is a straight swap out and the white band on these currently fitted diodes indicates the neg end ?? I think I could do this !!!

Yesterday was the only opportunity I had to test the panels, but even then there were only random passing pockets of clear sky rolling past through the cloud, most of the pockets were passing either above or below the sun anyway. At one point in the middle of the day in a rare 15-second window of sun, I was knocking on 9amps, but there wasn't much consistent clear sky through the middle of the day. Early arvo toward the end of the solar collection window, around 2 pm'ish a large patch of clear sky rolled through and I was getting a consistent 8amps. During that period I flicked over to one of my impressive blanket panels with a known output to compare with the fixed panel. I know from a perfect day summer test of the blanket its very capable of 7.5+amps, and at that point it was hovering 1 amp down from its capability at around the 6 - 6.5ish amp mark; from that I'm guessing that the 200w panels could possibly get up around the 9amp mark in good conditions which isn't too bad for a panel costing $128 delivered.

The battery I was using was very dodgy, and I ran my tyre pump off it to keep its already dodgy capacity screaming for power.

Trying to research the effect of winter sun and summer sun is virtually impossible. The only info I could find defaults to excess panel heat issues in summer, and snow and lesser solar time windows in winter. I couldn't find anything that simply compared the theoretical energy generation in the absence of external influences .... I was assuming in the absence of heat or snow etc that theoretically a higher closer summer sun would be better, thoughts ???

 

[Crusty181]

@Boots in Action ****** ABORT ABORT ABORT ******

With the power of the InterGooglyWeb from the code on the panel terminal box diodes (12SQ045) I seem to have identified the diodes as R-6 12A 45V Schottky Barrier Rectifier Diodes, I have no clue what that means but I pretty happy about it anyway, so straight up onto the roof those panels go.

 

[Boots in Action]

@Boots in Action ****** ABORT ABORT ABORT ******

With the power of the InterGooglyWeb from the code on the panel terminal box diodes (12SQ045) I seem to have identified the diodes as R-6 12A 45V Schottky Barrier Rectifier Diodes, I have no clue what that means but I pretty happy about it anyway, so straight up onto the roof those panels go.

@Crusty181 .
WARNING! WARNING! WARNING!!!
The 12A is okay but as each panel has an ocv of 22.3 volts and a working voltage of 18.3 volts, a combination of three panels in series is going to be over the working voltage of those diodes. The first figure is 12 which relates to current - ok, and the SQ indicated Schottky type, and the last figure is the max working voltage of only 45 volts - not okay with 3 panels in series. Okay if limited to 2 panels in series. Did not see any 15SQ60 diodes on Ebay, but 20SQ80 would be satisfactory. Personally, I do not like running electronics anywhere near their max rating to be on the safe side. Your call.
Had a quick look at your last post and can confirm that heat reduces the output of panels considerably - up to 15% loss. Hence in cold clear weather, generation is highest. Angle to the sun also has considerable affect too. Some way back on this thread, a member placed the optimum angle for generation at various places in Australia for summer and winter. I will see if I can find it. I think it said that the angle facing north should be approx that of your latitude?? I had a quick look at diode connections on your panels and yes, you can do any change if you can handle a soldering iron. Just be careful when doing this so that the heat from iron does not melt the plastic fittings, nor heat up the diode too much. Use a pair of small vice grips near soldering point to absorb some of the heat or some other means of protecting diode. I will send you a picture of my work together with a rough diagram of how the bypass diodes must be placed to be able to pass current around shaded panels. I will be back soon, so stay tuned.

 

[Crusty181]

@Crusty181 .
WARNING! WARNING! WARNING!!!
The 12A is okay but as each panel has an ocv of 22.3 volts and a working voltage of 18.3 volts, a combination of three panels in series is going to be over the working voltage of those diodes. The first figure is 12 which relates to current - ok, and the SQ indicated Schottky type, and the last figure is the max working voltage of only 45 volts - not okay with 3 panels in series. Okay if limited to 2 panels in series. Did not see any 15SQ60 diodes on Ebay, but 20SQ80 would be satisfactory. Personally, I do not like running electronics anywhere near their max rating to be on the safe side. Your call.
Had a quick look at your last post and can confirm that heat reduces the output of panels considerably - up to 15% loss. Hence in cold clear weather, generation is highest. Angle to the sun also has considerable affect too. Some way back on this thread, a member placed the optimum angle for generation at various places in Australia for summer and winter. I will see if I can find it. I think it said that the angle facing north should be approx that of your latitude?? I had a quick look at diode connections on your panels and yes, you can do any change if you can handle a soldering iron. Just be careful when doing this so that the heat from iron does not melt the plastic fittings, nor heat up the diode too much. Use a pair of small vice grips near soldering point to absorb some of the heat or some other means of protecting diode. I will send you a picture of my work together with a rough diagram of how the bypass diodes must be placed to be able to pass current around shaded panels. I will be back soon, so stay tuned.

Damn it .... there's always a 'but'. Are the Chinese Ebay ones ok??

 

[mikerezny]

The total current going into the controller was measured with my clamp meter at 1.38A, which is less than 0.5A from each of the 3 panels, bearing in mid that this low amount was limited to the output of the least efficient panel .

Just to show you that I do read all your reports:
Sorry, but as your panels are in SERIES, the current is the same, 1.38A, through all three panels.

cheers
Mike

 

[Boots in Action]

Just to show you that I do read all your reports:
Sorry, but as your panels are in SERIES, the current is the same, 1.38A, through all three panels.

cheers
Mike

Absolutely correct @mikerezny. Sorry to give "bum" info.Thanks, just a slip of the electrical thinking late at night.

 

[Boots in Action]

Damn it .... there's always a 'but'. Are the Chinese Ebay ones ok??

I have not found any problem with them @Crusty181 and in any case, China makes most of them now too. Here is the link for the ones I purchased.

https://www.ebay.com/itm/5pcs-New-1...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

 

[Crusty181]

I have not found any problem with them @Crusty181 and in any case, China makes most of them now too. Here is the link for the ones I purchased.

https://www.ebay.com/itm/5pcs-New-15SQ060-15A-60V-Schottky-Rectifiers-Diode/201563235238?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

Thanks Boots, appreciate your insight. Your supplier has the 20/80 ones so Ill grab them to be on the safe side as you suggest

 

[mikerezny]

You only have to ask, and you shall receive Sir.

I presume the bypass diode x 2 is a straight swap out and the white band on these currently fitted diodes indicates the neg end ?? I think I could do this !!!

Yesterday was the only opportunity I had to test the panels, but even then there were only random passing pockets of clear sky rolling past through the cloud, most of the pockets were passing either above or below the sun anyway. At one point in the middle of the day in a rare 15-second window of sun, I was knocking on 9amps, but there wasn't much consistent clear sky through the middle of the day. Early arvo toward the end of the solar collection window, around 2 pm'ish a large patch of clear sky rolled through and I was getting a consistent 8amps. During that period I flicked over to one of my impressive blanket panels with a known output to compare with the fixed panel. I know from a perfect day summer test of the blanket its very capable of 7.5+amps, and at that point it was hovering 1 amp down from its capability at around the 6 - 6.5ish amp mark; from that I'm guessing that the 200w panels could possibly get up around the 9amp mark in good conditions which isn't too bad for a panel costing $128 delivered.

The battery I was using was very dodgy, and I ran my tyre pump off it to keep its already dodgy capacity screaming for power.

Trying to research the effect of winter sun and summer sun is virtually impossible. The only info I could find defaults to excess panel heat issues in summer, and snow and lesser solar time windows in winter. I couldn't find anything that simply compared the theoretical energy generation in the absence of external influences .... I was assuming in the absence of heat or snow etc that theoretically a higher closer summer sun would be better, thoughts ???

View attachment 63728 View attachment 63729

From what I can see, there are three silver wires sneaking up from the actual solar panel. This is an indication that your solar panel is actually wired as two sub panels connected in series. The two diodes are wired such that each diode is a bypass diode for one of the sub panels.

If you want to wire these panels in series there is nothing else you need to do. Regardless of how many panels you wire in series, the maximum reverse voltage across any one of the diodes is the max voltage that a single sub panel can produce. In this panel, max voltage of the panel is 22.3V and thus the max voltage across any one diode is 11.15V and since the maximum reverse voltage rating of the diodes is 45V, all is good.

Well, at least that is my understanding.

cheers
Mike

 

[Crusty181]

From what I can see, there are three silver wires sneaking up from the actual solar panel. This is an indication that your solar panel is actually wired as two sub panels connected in series. The two diodes are wired such that each diode is a bypass diode for one of the sub panels.

If you want to wire these panels in series there is nothing else you need to do. Regardless of how many panels you wire in series, the maximum reverse voltage across any one of the diodes is the max voltage that a single sub panel can produce. In this panel, max voltage of the panel is 22.3V and thus the max voltage across any one diode is 11.15V and since the maximum reverse voltage rating of the diodes is 45V, all is good.

Well, at least that is my understanding.

cheers
Mike

You Sir (along with the other Sir, @Boots in Action) are just true gentlemen and a wealth of combined knowledge. What you say makes sense (actually what @Boots in Action said made sense too) but I like your sense a tiny bit more because it suits me better and I can mount the panels now.

(PS @mikerezny and @Boots in Action could I interest either of both of you in some quality 20SQ080 20A 80V Schottky Rectifiers Diodes that I may have en route downunder. We could have a bidding war, but you'll need to wait until November for them to arrive )

 

[Crusty181]

From what I can see, there are three silver wires sneaking up from the actual solar panel. This is an indication that your solar panel is actually wired as two sub panels connected in series. The two diodes are wired such that each diode is a bypass diode for one of the sub panels.

If you want to wire these panels in series there is nothing else you need to do. Regardless of how many panels you wire in series, the maximum reverse voltage across any one of the diodes is the max voltage that a single sub panel can produce. In this panel, max voltage of the panel is 22.3V and thus the max voltage across any one diode is 11.15V and since the maximum reverse voltage rating of the diodes is 45V, all is good.

Well, at least that is my understanding.

cheers
Mike

Just mulling over what you've said, and remember I have absolutely zero clue what I'm banging on about.

Connected in series the voltage at the regulator will the combined voltage total of the 6 x sub-panels ie 66.9v. The voltage of each sub-panel combines, and the input into the controller is 66.9v so how does it get from the initial 11.15v to 66.9v without exceeding at least one 45v diode along the way. Each sub-panel produces 11.15v, and then combines with its second sub-panel to produce 22.3v per panel, does it then not keep combining all 6 x 11.15v outputs across all of the sub-panels adding up as it goes, exceeding the capacity of the 45v diodes by the time it adds the output of the last panel on its path south to the promised land ????

Im just a glaring example of the dangers of stupid uneducated thinking.

 

[mikerezny]

Just mulling over what you've said, and remember I have absolutely zero clue what I'm banging on about.

Connected in series the voltage at the regulator will the combined voltage total of the 6 x sub-panels ie 66.9v. The voltage of each sub-panel combines, and the input into the controller is 66.9v so how does it get from the initial 11.15v to 66.9v without exceeding at least one 45v diode along the way. Each sub-panel produces 11.15v, and then combines with its second sub-panel to produce 22.3v per panel, does it then not keep combining all 6 x 11.15v outputs across all of the sub-panels adding up as it goes, exceeding the capacity of the 45v diodes by the time it adds the output of the last panel on its path south to the promised land ????

Im just a glaring example of the dangers of stupid uneducated thinking.

Hi,

Each diode is across only one sub panel. There are two situations to be concerned with:

1: This sub-panel is in sunlight and producing 11.15V. In this case the diode is not conducting and is reverse-biased. So the relevant spec for the diode in this condition is the maximum reverse voltage it can handle without breaking down.

2: This sub-panel is in shade but some of the other sub panels are in sun and can produce current. In this case, the diode conducts to let the current bypass the this sub panel. So the relevant spec for the diode is the maximum forward current that the diode can handle the panel can produce about 12A which is the same rating as the diode.

If you wanted to be super careful, you could wait until your new diodes arrive and put them in. You would then have a greater safety margin on the bypass current.

Here is a couple of links discussing the operation of bypass diodes which have much nicer diagrams than I would do:

https://www.powerfromsunlight.com/s...at-you-should-know-about-solar-bypass-diodes/

https://www.pveducation.org/pvcdrom/modules-and-arrays/bypass-diodes

cheers
Mike

 

[Crusty181]

Hi,

Each diode is across only one sub panel. There are two situations to be concerned with:

1: This sub-panel is in sunlight and producing 11.15V. In this case the diode is not conducting and is reverse-biased. So the relevant spec for the diode in this condition is the maximum reverse voltage it can handle without breaking down.

2: This sub-panel is in shade but some of the other sub panels are in sun and can produce current. In this case, the diode conducts to let the current bypass the this sub panel. So the relevant spec for the diode is the maximum forward current that the diode can handle the panel can produce about 12A which is the same rating as the diode.

If you wanted to be super careful, you could wait until your new diodes arrive and put them in. You would then have a greater safety margin on the bypass current.

Here is a couple of links discussing the operation of bypass diodes which have much nicer diagrams than I would do:

https://www.powerfromsunlight.com/s...at-you-should-know-about-solar-bypass-diodes/

https://www.pveducation.org/pvcdrom/modules-and-arrays/bypass-diodes

cheers
Mike

Hmmm, those two links are way above my pay grade (just to clear, they in english, right?. Ha). The Chinese panel man who sold me the panels insisted (in a messenger text chat) that upto 5 x their 200w panels can be connected in series, no worries.

 

[Boots in Action]

Just mulling over what you've said, and remember I have absolutely zero clue what I'm banging on about.

Connected in series the voltage at the regulator will the combined voltage total of the 6 x sub-panels ie 66.9v. The voltage of each sub-panel combines, and the input into the controller is 66.9v so how does it get from the initial 11.15v to 66.9v without exceeding at least one 45v diode along the way. Each sub-panel produces 11.15v, and then combines with its second sub-panel to produce 22.3v per panel, does it then not keep combining all 6 x 11.15v outputs across all of the sub-panels adding up as it goes, exceeding the capacity of the 45v diodes by the time it adds the output of the last panel on its path south to the promised land ????

Im just a glaring example of the dangers of stupid uneducated thinking.

Hello again @Crusty181 , @mikerezny has provided some beaut links on how by-pass diodes work and how they are connected. I hope that clarifies those areas you were interested. Great demonstration of how/where electrical current flows in a solar panel. Just in case you are in doubt of what some electrical words mean, this may help you in SIMPLE language.
Reverse bias.............Connected so that electrical current will NOT flow through diode, regardless of current or voltage applied. (within max limits of specs)
Forward bias............Connected so that electrical current WILL flow through diode, when required as long as current and voltage are within specs.
Diodes are shown as arrow heads with a line across the point of arrow head. Point of arrow head indicates direction current is allowed to flow. The line across the point of arrow head indicts a blocking of any current flow from that direction towards tip of arrow head.
I admit I do tend to over engineer when upgrading electrical things, so when replacing the diodes in my panels with the superior Schottky type, I went for higher voltage protection for the series connection. Good to see that the later model (or better) panels now use Schottky diodes ( instead of the standard Barrier type). Schottky have much LOWER forward voltage drop. This means less voltage loss across diode/s, so higher voltage to your controller, combined with greater protection for your panels against "hot spots" and burn through.
Below is another SIMPLE diagram regarding how bypass diodes work when part or all of the solar cells are shaded. Not quite as technical as @mikerezny .

Full details on this link:
http://www.alternative-energy-tutorials.com/energy-articles/bypass-diode.html

 

[Boots in Action]

Hmmm, those two links are way above my pay grade (just to clear, they in english, right?. Ha). The Chinese panel man who sold me the panels insisted (in a messenger text chat) that upto 5 x their 200w panels can be connected in series, no worries.

Hi @Crusty181 , hang in there. Don't throw your hands in the air just yet!! School is still in. Have a read of my latest post which is nowhere near as involved for beginners as @mikerezny's , but will help you understand his detailed version a lot better.
Your Chinese man was pretty correct with the following provisos:
1. The open circuit (no load or connection to anything switched on ) voltage of each panel is rated at 22.3 volts . The max working voltage (at peak production and under very light load or work (a single LED light???) of each panel is rated at 18.3 volts. If you connect all 5 panels in series, that would total 111.5 volts and be beyond the limit of tour MPPT controller (rated to 100 volts). But this would never occur as you would never have your controller and electrical system NOT connected to something!! With 5 panels connected, at working voltage 18.3 X 5 equals 91.5 volts. In theory, this could be attained in very cold bright conditions but only with very light loads. Whenever you place an electrical load on this sort of system, you will get a voltage drop. If your mighty tug is purring away at 2000rpm in neutral, the rpm will drop when you put it into gear with 3 tonne behind it . Yes, you would probably be able to get it up to 2000rpm again with extra power, but the electrical system does not have that ability.
2. You would have to have a good MPPT controller capable of handling such high voltage. Myself, I would not like to run any system constantly at close to maximum (even your great V8 tug!!) Full noise as @Drover says.

 

[Crusty181]

I only have the 3 x 200w panels. My MPPT controller is 40a, 100v max input so are the 3 x panels with the installed Schottky diodes ok to install in series as is ?? or do I need the higher rate diodes

 

[Boots in Action]

I only have the 3 x 200w panels. My MPPT controller is 40a, 100v max input so are the 3 x panels with the installed Schottky diodes ok to install in series as is ?? or do I need the higher rate diodes

As @mikerezny said, you are okay to go @Crusty181 unless you wish to "over engineer" as I have done. Should have no probs if connected correctly in series. You won't get anywhere near 40A from panels in series - only about 8 or 9 A- but it will be at 50 odd volts. So the length and thickness of cabling to controller is not as critical as in a parallel setup. At 8A from the panels into controller at 50 volts, you get approx 400 watts. When this is reduced to battery voltage, say 13 volts, you should have about 25 to 30A coming into battery/ies. Keep length between controller and battery/ies as short as possible and also able to carry this sort of current. Good luck and let us know how you go.