Victron BlueSolar charge controller

[socaldmax]

Originally Posted by DotDun

It's very easy to refute the video, there were no bypass diodes. Period!

Show me a video with bypass diodes proving that serial panels produce more power than parallel in partially shaded conditions.

What they showed in that video is what is typically happening on sailboats all over the world. In other words, I doubt there are nearly as many bypass diodes installed out there as some seem to think.

[socaldmax]

Here's a nice serial vs parallel video with mismatched panels, basically the same thing as a shaded panel.

https://www.youtube.com/watch?v=P3YtBrymJdA

[DotDun]

Originally Posted by socaldmax

Show me a video with bypass diodes proving that serial panels produce more power than parallel in partially shaded conditions.

What they showed in that video is what is typically happening on sailboats all over the world. In other words, I doubt there are nearly as many bypass diodes installed out there as some seem to think.

Go and read how diodes work and you won't need a video.

Any quality solar panel with more than 36 cells sold in the last 10 years has bypass diodes.

[john61ct]

Some panels have bypass diodes installed between strings. Many cheaper and smaller ones don't, and easy enough to DIY if you like.

But they only help marginally, not nearly as much as larger numbers of smaller controllers.

And yes there is little reason to put in disconnect switches between the panels and controllers, much less circuit protection. Maybe an Anderson powerpole buss?

https://powerwerx.com/powerpole-power-distribution

[john61ct]

Originally Posted by DotDun

Any quality solar panel with more than 36 cells sold in the last 10 years has bypass diodes.

Well that's a tautology if you define quality by the presence of diodes.

[DotDun]

Originally Posted by john61ct

Some panels have bypass diodes installed between strings. Many cheaper and smaller ones don't, and easy enough to DIY if you like.

I have 60 cell panels with 3 diodes. How would one duplicate with DIY?

Originally Posted by john61ct

But they only help marginally, not nearly as much as larger numbers of smaller controllers.

A controller per panel is a good solution, but multiple bypass diodes per panel will allow a partial panel to contribute whereas no bypass diodes and shading could kill the whole panel.

Originally Posted by john61ct

And yes there is little reason to put in disconnect switches between the panels and controllers, much less circuit protection. Maybe an Anderson powerpole buss?

https://powerwerx.com/powerpole-power-distribution

Some controllers recommend disconnecting the panels before working on the controller. YMMV.

[DotDun]

Originally Posted by john61ct

Well that's a tautology if you define quality by the presence of diodes.

Let me rephrase, cheap panels don't have diodes.

[john61ct]

Originally Posted by socaldmax

Here's a nice serial vs parallel video with mismatched panels, basically the same thing as a shaded panel.

No, they're matching voltages, while dropped voltage is what causes shade issues.

If they used one MPPT controller per panel (each putting out 30V+ so fine for MPPT) they would have added nearly 10% or 10A to the total there, and if one got partial shading there would have been zero zilch nada effect on the other's output.

Bypass diodes within or between those panels wouldn't have helped much if at all, whether serial or parallel.

[socaldmax]

Originally Posted by DotDun

Go and read how diodes work and you won't need a video.

Any quality solar panel with more than 36 cells sold in the last 10 years has bypass diodes.

I know how diodes work.

I said show me a video of them working as you advertised. Just grab a video camera, partially shade one of your panels, and show us that your solar harvest dropped by only 15% or 25% or whatever percentage of the shaded area of the panel works out to. Just upload the video to youtube.

Or find a video on youtube that proves it, if you can. You keep claiming that all panels produced in the last 10 yrs come with bypass diodes. If that's really the case, there should be plenty of videos to prove it. Very simple.

[DotDun]

Originally Posted by socaldmax

I know how diodes work.

I said show me a video of them working as you advertised. Just grab a video camera, partially shade one of your panels, and show us that your solar harvest dropped by only 15% or 25% or whatever percentage of the shaded area of the panel works out to. Just upload the video to youtube.

Or find a video on youtube that proves it, if you can. You keep claiming that all panels produced in the last 10 yrs come with bypass diodes. If that's really the case, there should be plenty of videos to prove it. Very simple.

I don't need a video. If you feel so inclined, provide a video showing bypass diodes don't work!

[john61ct]

Originally Posted by DotDun

I have 60 cell panels with 3 diodes. How would one duplicate with DIY?

As I said, with smaller panels, single strings. Put them in series, wire diodes in between.

I'm not recommending that, they really don't help much in practice.

Originally Posted by DotDun

A controller per panel is a good solution

Thanks, that was my point.

Originally Posted by DotDun

Some controllers recommend disconnecting the panels before working on the controller.

Does that include Victron?

If so, use the powerplugs as I pointed to.

Or toss a towel over them.

Switches are overkill, was my other point.

[socaldmax]

Originally Posted by john61ct

No, they're matching voltages, while dropped voltage is what causes shade issues.

If they used one MPPT controller per panel DING DING DING! What have I been saying??

(each putting out 30V+ so fine for MPPT) they would have added nearly 10% or 10A to the total there, and if one got partial shading there would have been zero zilch nada effect on the other's output.

Bypass diodes within or between those panels wouldn't have helped much if at all, whether serial or parallel. I know that, you know that, let's see if someone else believes you...

My testing with partially shaded panels indicated a huge drop in current and a smaller drop in voltage. Just from memory, the voltage dropped from 37v down to about 30v, the current dropped from about 12A down to less than 2A. This was a single panel on an MPPT controller.

Here's a video where they do some testing with partial shading of identical panels, which is what most people have connected together. This video shows slightly more power out in parallel mode with no shade (might have been more sun at that time) and significantly more power in parallel with partial shading.

https://www.youtube.com/watch?v=ofo1HQyGG8s

[socaldmax]

Originally Posted by DotDun

I don't need a video. If you feel so inclined, provide a video showing bypass diodes don't work!

I've already provided 2 videos using panels that are either new or just a couple of yrs old. YOU are the one making the claim they they don't have bypass diodes.

I've done some testing myself on brand new panels mfd in the latter half of 2016, and they acted like they didn't have bypass diodes.

I have yet to see in video or in person, any panels that exhibited behavior that indicated they have working bypass diodes. That's why I'm inviting you to find one, or make one.

[john61ct]

He'll just say you shouldn't buy panels without diodes.

Many say the semi-flex panels that zipper-mount to a bimini are no good too. Yes they don't last as long, but at a buck a watt or so **delivered**, don't need big ugly support racks constructed, I don't mind, long as they make it 2-3 years.

There definitely are panels with bypass diodes, bigger more expensive ones.

I'll go smaller, cheaper, paired with lots of smaller cheaper controllers.

And we'll both be happy with the breeze pushing us around the ocean 8-)

[DotDun]

Originally Posted by socaldmax

I've already provided 2 videos using panels that are either new or just a couple of yrs old. YOU are the one making the claim they they don't have bypass diodes.

I'm confused, are you claiming the panels in the videos do have bypass diodes?

You claim to know how bypass diodes work, why are you questioning if they exist in those videos?

Originally Posted by socaldmax

I've done some testing myself on brand new panels mfd in the latter half of 2016, and they acted like they didn't have bypass diodes.

And did they have bypass diodes?

Originally Posted by socaldmax

I have yet to see in video or in person, any panels that exhibited behavior that indicated they have working bypass diodes. That's why I'm inviting you to find one, or make one.

Let me explain. I have 180 cells wired in series, each group of 20 has a bypass diode. I don't have shading issues, but, if I have a single shading issue, I lose the group 20 vs losing 180 with no bypass diodes. Since my 180 cells are distributed across 3 panels, if I were wired in parallel, I would lose 60 cells with a single shading problem.