Solar The Solar Panel Thread

[Boots in Action]

An observation......for simplicity and to reiterate what most of the early discussion focused on

• Most solar panels now come with blocking diodes
• A portable panel, to supplement the standard roof panels, must have its own separate controller and be wired directly to the battery
• Attach regulators as close to the battery as possible
• Keep the wiring to the best possible size..6 or 8
• Keep the portable panel cable as short as possible, within the range needed...10m is possible if the cable size is correct
• Regulator must be able to cope with panel specs...at least 20 amps, preferably 30
• Regulator can be MPPT for optimum results but a PWM is adequate for most occasions. MPPT is superior, but most of the others are OK for basic requirements
• Keep panels clean
• Know your power requirements and charging and battery capacity before overspending
• KISS

You guys are certainly doing a good job with the investigation but, as said earlier, I think we're getting bogged down a bit in the complexities of MPPT, diodes etc...which is fine but doesn't really help sorting out the more basic requirement of most who are looking to set up a good 12v chárging system. I'm concerned that confusion will result.

I know many of us have been using good 12v systems for many years by following basic principles ...in our case for over 20 years....and I know if I'd stumbled on this very complicated discussion, needing some simple advice on solar charging, I'd run a mile!

You are pretty right on that @Dobbie . The trouble is that technology is ALWAYS on the move and improving all the time. 20 years ago, I doubt anyone had even heard of MPPT controllers, let alone much choice or info on standard PWM type controllers. @Moto Mech said " a little knowledge is dangerous" and it is too. If you do not want to get into trouble, stick to the simple things that you know, but that way you do not keep up with the latest in technology and miss out on chances to improve your system. The other alternative if you are not too sure is to ACTIVELY seek advice and there is certainly no shortage of that on this forum. It is still up to the individual as to where they want to be. And I do not think you would have "run a mile" back then if the more technical information available was simply explained to you. Could I be right about this?

Notwithstanding what I have said above, it is good to be reminded that a lot of members may not have any , or only limited tech knowledge, to be interested in a lot of technical jargon and that you are moderating on their behalf. Cheers

Note: IMHO, line 2 is not correct. A portable solar panel CAN be connected without its own controller IF it is connected in PARALLEL with roof top panels. Understandably, one would need to have an Anderson plug on side of van (to plug in portable panel) and have that wired in PARALLEL with the other input wires from roof panels. This eliminates need for separate controller, although one would have to bypass the controller on back of portable panel AND make sure blocking diodes were in place. The other problem then is that the portable panel is restricted to just being plugged into van Anderson plug and loses versatility of separate use for other purposes unless controller is back in circuit. Probably TOO complex for a lot, but still possible!! Technology is tough stuff for some.

 

[Moto Mech]

 

[Boots in Action]

Hi @Moto Mech,
oh good. This looks like a simple panel with a single array since I can see only two wires coming in from the top from the solar cell.
The square black device ACROSS the cell output looks to be two diodes wired in parallel as a BYPASS diode.

The photo is not quite clear enough. Is it possible to read the part number on the device? It looks like 20SQ???

cheers
Mike

Hi @mikerezny , looks like a Schottky alright - rating of 20A and 45V. Recommended for solar panel and where heat in junction box at rear of panel is/could be high. Note extensive "heat sinking" with the soldering. The site I just looked up quotes a 16A schottky type "should be safe up to 12A when temps in junction box at rear of panel is high". Diode derated because of possible heat build up!! A good upgrade. Interesting - another variable!! Sorry @Dobbie for introducing more techo stuff.

 

[Moto Mech]

So, are you guys saying its got bypass diodes fitted and good to wire in in series without "adding extras" straight to my controller?
Sorry, havent done much with this sort of thing(my last panels I was told it was good to go out of box, wondering now if they really were).

 

[Crusty181]

So, are you guys saying its got bypass diodes fitted and good to wire in in series without "adding extras" straight to my controller?
Sorry, havent done much with this sort of thing(my last panels I was told it was good to go out of box, wondering now if they really were).

Where did source your panels? Are you mounting onto polycarb roof sheet? MS Polymer base adhesive appears to be a good option, it is cited to adhere to fibreglass, alum and polycarb. I should get my van back this week, so ill test the adhesive.

 

[Moto Mech]

Where did source your panels? Are you mounting onto polycarb roof sheet? MS Polymer base adhesive appears to be a good option, it is cited to adhere to fibreglass, alum and polycarb. I should get my van back this week, so ill test the adhesive.

Ebay
Yep, will mount to roof sheeting, always used roof and gutter silicone to glue panels down, never lost one yet. Have had to remove one to and it was no easy job

 

[Boots in Action]

So, are you guys saying its got bypass diodes fitted and good to wire in in series without "adding extras" straight to my controller?
Sorry, havent done much with this sort of thing(my last panels I was told it was good to go out of box, wondering now if they really were).

Hi @Moto Mech , did your panels come with their OWN solar controllers attached to back?? If so, that would mean that there are NO blocking diodes in the panels as that the only diodes you have to worry about are those attached to panel. They have to be Bypass diodes in the circuit. And the way they are connected at the back of the panel confirms this. Go for it. BUT YOU HAVE TO BYPASS THE CONTROLLERS ATTACHED TO THE BACK OF EACH PANEL!! That way all current and voltage is controlled by the MPPT controller attached to van. If unsure, just ask myself or @mikerezny . We do not want any disasters caused by misunderstandings or wrong connections. Are you game to trust us "Tech Heads'??? You do know how to wire panels in SERIES don't you?? Please do not abuse me for asking that question as I am trying to cover ALL bases so their are NO mistakes!!i

 

[Moto Mech]

Hi @Moto Mech , did your panels come with their OWN solar controllers attached to back?? If so, that would mean that there are NO blocking diodes in the panels as that the only diodes you have to worry about are those attached to panel. They have to be Bypass diodes in the circuit. And the way they are connected at the back of the panel confirms this. Go for it. BUT YOU HAVE TO BYPASS THE CONTROLLERS ATTACHED TO THE BACK OF EACH PANEL!! That way all current and voltage is controlled by the MPPT controller attached to van. If unsure, just ask myself or @mikerezny . We do not want any disasters caused by misunderstandings or wrong connections. Are you game to trust us "Tech Heads'???

No controller came with panel, its simply the junction box pictured a few posts back and 1mt leads

 

[mikerezny]

View attachment 56928

Hi @Moto Mech,
thanks for the new photo. Are you able to read the part number, especially the characters under the splodge?
Perhaps part number of the component on the other panel is easier to read.

It is definitely two diodes. They appear to be Schottky. And both diodes are wired in parallel and connected as bypass.
So, your two panels should be good to go as is, but ONLY if they are wired in SERIES.

Cheers
Mike

 

[Boots in Action]

Hi @Moto Mech,
thanks for the new photo. Are you able to read the part number, especially the characters under the splodge?
Perhaps part number of the component on the other panel is easier to read.

It is definitely two diodes. They appear to be Schottky. And both diodes are wired in parallel and connected as bypass.
So, your two panels should be good to go as is, BUT only if they are wired in SERIES.

Cheers
Mike

I agree @mikerezny . That diode is the T-02 ??package and lets you have two diodes in the one package - a superior type for hot panels. I am going to stick with the axial barrier type as they will be easier to solder in to replace originals which are only rated to 10A. The MPPT controller (or any other type controller PWM) does the blocking when panels are not producing eg at night or very dark situations. Under the "splodge" I can make out the the last figure and so the complete last figures are 045 - meaning 45V rated. Just as well that @Moto Mech asks about the diodes, because if used straight and in Parallel) as MAY have happened before, there was NO panel protection when one was shaded/partially shaded. That would cause them to "cook" in 40C heat, let alone dealing with direct sun!! @Moto Mech , could this have happened to your original panels??

 

[Boots in Action]

No controller came with panel, its simply the junction box pictured a few posts back and 1mt leads

Hi @Moto Mech , you are getting to the sharp end of this saga now. As the panels came, it appears that the seller is depending on you to connect ONLY ONE panel to YOUR own controller. That would be okay if done that way - bypass diodes on panel AND blocking diode provided for in YOUR controller. BUT, if you were going to use more than ONE panel connected in PARALLEL, then it would need a separate blocking diode on EACH panel to isolate it from the operation of the other panel.
As you are going in SERIES, no need to worry. Bypass on each panel protects the shaded panel and the blocking diode in controller prevents battery discharge through the panels at night. It goes to show that a little knowledge is helpful, but good advice on EACH INDIVIDUAL SETUP can reap rewards AND save hassles and money. Someone on this forum says "learn from other's mistakes. You do not live long enough to learn them all!!" See also my reply to @mikerezny about what may?? have happened to you last lot of flexi panels.

 

[Boots in Action]

Hi @Moto Mech,
thanks for the new photo. Are you able to read the part number, especially the characters under the splodge?
Perhaps part number of the component on the other panel is easier to read.

It is definitely two diodes. They appear to be Schottky. And both diodes are wired in parallel and connected as bypass.
So, your two panels should be good to go as is, but ONLY if they are wired in SERIES.

Cheers
Mike

Hi @mikerezny , I don't know about you, but I am going to have a few (a good few) when this thread is over. My head is really overloaded and needs to be reset - and I need more than cider!! Thanks for your very close support and advices to @Moto Mech who should now benefit immensely. This forum is really great when you get to help others who are prepared to ask questions, no matter how silly they seem. There is always someone out there with the necessary knowledge and/or experience to step up and help.

Got to have a beer or two if I ever have a need to go to cold wet Melbourne again. I have been watching the weather and am glad I am in sunny Queensland. It travelling north again, make sure you contact me and we can exchange a few yarns and enjoy a drink or two. I have been also thinking of lining up my old mate @Drover on the Cooloola Coast and torment him a bit!!

 

[mikerezny]

Hi @mikerezny , I don't know about you, but I am going to have a few (a good few) when this thread is over. My head is really overloaded and needs to be reset - and I need more than cider!! Thanks for your very close support and advices to @Moto Mech who should now benefit immensely. This forum is really great when you get to help others who are prepared to ask questions, no matter how silly they seem. There is always someone out there with the necessary knowledge and/or experience to step up and help.

Got to have a beer or two if I ever have a need to go to cold wet Melbourne again. I have been watching the weather and am glad I am in sunny Queensland. It travelling north again, make sure you contact me and we can exchange a few yarns and enjoy a drink or two. I have been also thinking of lining up my old mate @Drover on the Cooloola Coast and torment him a bit!!

Hi @Boots in Action,
sure, when you get down this way, hopefully we can get together.

At this stage, we seem to be planning to escape to Qld each winter. Well, at least as long as my son is working in Gladstone. So it would be good to get together.

cheers
Mike

 

[Moto Mech]

Cheers guys, clear as mud now
No really, all good. Just need complete the package and wire it all up.
No hurry for me as haven't got a high useage of power yet till i pull the 3way fridge out and put a compressor fridge in. Just waiting on approval from the BOSS.
Thanks heaps all, have a much better understanding of the whole bypass/blocking diode thing as well as a better understanding of parallel/series.

 

[Bellbirdweb]

So my new MPPT controller arrived today.

Reading through the manual, it seems to have all of the different programs for different battery types and lots more, and the dimemsions are even right so it will fit

Will need to wait till the weekend so I can fit it and the new inverter

 

[Boots in Action]

Cheers guys, clear as mud now
No really, all good. Just need complete the package and wire it all up.
No hurry for me as haven't got a high useage of power yet till i pull the 3way fridge out and put a compressor fridge in. Just waiting on approval from the BOSS.
Thanks heaps all, have a much better understanding of the whole bypass/blocking diode thing as well as a better understanding of parallel/series.

Go for it @Moto Mech , great to deal with - a pleasure indeed!! When connected up correctly, your controller should show somewhere between 30 and 40 volts and a considerable amount of amps available going into battery at battery voltage of somewhere between 12.5 and 13.9V depending on load and state of battery. I would estimate a charging current of probably 20A at least in good conditions. Make sure input wires to battery from controller are as short as possible and are capable of handling the greater current. Refer earlier exchanges with other members. All members will be keen to hear how you went. Good luck.

 

[Boots in Action]

View attachment 56932 So my new MPPT controller arrived today.

Reading through the manual, it seems to have all of the different programs for different battery types and lots more, and the dimemsions are even right so it will fit

Will need to wait till the weekend so I can fit it and the new inverter

Hi @Bellbirdweb , you have been keeping a low profile of late whist @mikerezny and I have been assisting @Moto Mech . So now you too have joined the MPPT group. Noticed that your unit is approx 40mm less in height than the Epever of same output. Should do the trick for you. I assume that you are going to a SERIES connection with your panels too.

Did you see the note at the bottom of details that controller needs battery voltage plus 5V from panels before start up?? This should not be a problem with your controller if connected in series - even on a cloudy day you will beat that easily. I bet you cannot wait until the weekend to get stuck into it and try it out. After all the information floating around, I will be keen to hear how a "tech head" like you gets on. Good luck.

 

[Bellbirdweb]

Hi @Bellbirdweb , you have been keeping a low profile of late whist @mikerezny and I have been assisting @Moto Mech . So now you too have joined the MPPT group. Noticed that your unit is approx 40mm less in height than the Epever of same output. Should do the trick for you. I assume that you are going to a SERIES connection with your panels too.

Did you see the note at the bottom of details that controller needs battery voltage plus 5V from panels before start up?? This should not be a problem with your controller if connected in series - even on a cloudy day you will beat that easily. I bet you cannot wait until the weekend to get stuck into it and try it out. After all the information floating around, I will be keen to hear how a "tech head" like you gets on. Good luck.

Thanks @Boots in Action, yes the size of the Epever was the reason I didn't go with it, even with its remote it then would have meant finding a new location and re-cabling.

The specs on the wonderfully named Pangfusun controller looked pretty good on line, and now it has arrived, it looks well built, and the instructions are not in chinglish.

Yep at least initially I'm sticking with parallel so it will be a straight swap from my PWM controller to the MPPT.

The controller has lost of history logging built in so I should be able to see what's happening from a charge point of view.

My main job for the weekend will be to tidy up the Jayco wiring, add in my new inverter and install the new controller so I've got my work cut out.

 

[Crusty181]

Please do not abuse me for asking that question as I am trying to cover ALL bases so their are NO mistakes!!i

That would be a bit like beating up on the Ambos when they arrive for your heart attack. Having all you guys bouncing off each other, and providing your time and expertise to the rest of knuckle heads is priceless.

Opportune time to pass on a sincere thanks. Im a lot wiser for your work and I sure in the short and long term my money will be better spent.

Three cheers to all of you "tech heads", now back to work with the lot of ya

An observation......for simplicity and to reiterate what most of the early discussion focused on

• Most solar panels now come with blocking diodes
• A portable panel, to supplement the standard roof panels, must have its own separate controller and be wired directly to the battery
• Attach regulators as close to the battery as possible
• Keep the wiring to the best possible size..6 or 8
• Keep the portable panel cable as short as possible, within the range needed...10m is possible if the cable size is correct
• Regulator must be able to cope with panel specs...at least 20 amps, preferably 30
• Regulator can be MPPT for optimum results but a PWM is adequate for most occasions. MPPT is superior, but most of the others are OK for basic requirements
• Keep panels clean
• Know your power requirements and charging and battery capacity before overspending
• KISS

You guys are certainly doing a good job with the investigation but, as said earlier, I think we're getting bogged down a bit in the complexities of MPPT, diodes etc...which is fine but doesn't really help sorting out the more basic requirement of most who are looking to set up a good 12v chárging system. I'm concerned that confusion will result.

I know many of us have been using good 12v systems for many years by following basic principles ...in our case for over 20 years....and I know if I'd stumbled on this very complicated discussion, needing some simple advice on solar charging, I'd run a mile!

Before I stated looking at adding a couple of panels to my van @Dobbie I would have agreed with you 100%, but its increasingly looking like a topic that simply cant be "skimmed" over, there seems to be too many compounding issues that are effected by every decision. A single small wrong turn, wrong connection, missing diode could end in disaster as @Moto Mech may have discovered previously. I dont have the room in my head to absorb all the tech stuff, but I think Id be foolish with my money if I didnt take heed. (dang it ... )

I much prefer to get @mikerezny to pop down to the factory and install and wire up my new panels and controller, after he's found the appropriate ones I need .... (that's not a throw away statement @mikerezny )

 

[mikerezny]

I much prefer to get @mikerezny to pop down to the factory and install and wire up my new panels and controller, after he's found the appropriate ones I need .... (that's not a throw away statement @mikerezny )

Hi @Crusty181,
I would be quite happy to come over and give you a hand.

cheers
Mike