How do I wire this solar panel? (OGRE B180-J24)

[FishFilet]

I have several OGRE B180-J24 solar panels that don't seem to be working well at all. I found a data sheet for them and it seems to indicate that they should be hooked up at the points I have labeled 2 and 3 as they are marked with a negative and positive in the diagram.

B180-J24.png

This is a 24v panel and the data sheet says the open circuit voltage should be 44v. I get the following with a multimeter.

• 40v on points 1 & 4
• 24v on 1 & 3
• 24v on 2 & 4
• 12v on 2 & 3

There are diodes between points 1&2, 2&3, 3&4.

The data sheet seems to indicate that I should hook up to points 2 & 3 but measuring the voltage across the points makes me thing I should use points 1 & 4.

Here is a link to the data sheet. What do you think?

[chrisski]

This open circuit voltage is 40.6 and a little different than you mentioned earlier. More closely matches pin 1 and 4. I'm not sure where to wire and this is different than the panels I looked at.

Ogre Panels.jpg

[bcroe]

I think you should connect to the highest voltage points, bracketing all the
bypass diodes, 1 & 4. Bruce Roe

[chrisski]

I am curious about the unlabeled pins, I’ll call them 0 and 5. Don’t now if you have something like this, but I have a smaller 50 ah lithium, homemade solar generator which has a MPPT I could hook a panel. I’d see how it did after a day of charging on pin 1 and 4.

Have you tried contacting the OGRE company? They seem to market themselves for stand alone panels to power a small battery pack off grid.

[FishFilet]

This open circuit voltage is 40.6 and a little different than you mentioned earlier. More closely matches pin 1 and 4. I'm not sure where to wire and this is different than the panels I looked at.

That's an older version but thank you.

[FishFilet]

I think you should connect to the highest voltage points, bracketing all the
bypass diodes, 1 & 4. Bruce Roe

That's what i am thinking. I just didn't wanted to see what others thought. Thank you.

I was wondering what the diodes were for. I was reading about bypass diodes between panels. Do these work the same way? letting the panel have some output when part of the panel is in the shade?

[FishFilet]

I am curious about the unlabeled pins, I’ll call them 0 and 5. Don’t now if you have something like this, but I have a smaller 50 ah lithium, homemade solar generator which has a MPPT I could hook a panel. I’d see how it did after a day of charging on pin 1 and 4.

Have you tried contacting the OGRE company? They seem to market themselves for stand alone panels to power a small battery pack off grid.

The unlabeled pinst don't give any voltage. Maybe they are grounded to the frame? I'll check that next time i can but they don't give out any voltage.

I did ask these questions to the OGRE company via email but have not gotten a response.

I did hook to pins 1 & 4 and it didn't seem to help. I'm going to look into if they need to be positive grounded because there is mention of that on their site. I just don't know anything about that. That's another thread however.

Next time I am around the panels I will check the current output with a multimeter of the shorted leads.

[chrisski]

Shame they did not answer. THe companies I’ve dealt with have answered me when I E-Mailed them. Guess I was lucky.\\

I did not think whether the panels or batteries mattered if they were positively grounded until electronics got added to these, and the components determined that.

[FishFilet]

Shame they did not answer. THe companies I’ve dealt with have answered me when I E-Mailed them. Guess I was lucky.\\

I did not think whether the panels or batteries mattered if they were positively grounded until electronics got added to these, and the components determined that.

It has something to do with high efficiency all back contact solar cells and surface polarization. Here is some info.

[Mike90250]

Diodes in the panel's Jbox are for bypass between rows of cells. Generally, bypass diodes are NOT installed between panels.
better solar stores sell bypass diodes to repair burnt diodes in a Jbox

[FishFilet]

Diodes in the panel's Jbox are for bypass between rows of cells. Generally, bypass diodes are NOT installed between panels.
better solar stores sell bypass diodes to repair burnt diodes in a Jbox

I see. I think I was referring to an article much like this one although it was talking about when a series string of panels gets partially shaded that the current for the entire string drops. Adding bypass diodes would help with that.

https://sinovoltaics.com/learning-center/off-grid/blocking-diode-bypass-diode-solar-panels/

[Mike90250]

That is a poorly written, very old, article. Since the mid 80's Charge Controllers provide the nighttime Blocking diode function.

Because modern panels include Bypass diodes,extra diodes are not needed between panels.

Shade on even a small portion of a panel can drastically reduce output, and that shaded are will often activate the bypass diode(s). This is less than optimal, because there is no harvestable energy in shade, so the simple solution is to remove the item causing the shade, allowing the panels to produce full power

[FishFilet]

That is a poorly written, very old, article. Since the mid 80's Charge Controllers provide the nighttime Blocking diode function.

Because modern panels include Bypass diodes,extra diodes are not needed between panels.

Shade on even a small portion of a panel can drastically reduce output, and that shaded are will often activate the bypass diode(s). This is less than optimal, because there is no harvestable energy in shade, so the simple solution is to remove the item causing the shade, allowing the panels to produce full power

Yes well that's not the actual article. It was article like this one however. It doesn't really matter though. Thank you for all of the help.

[oldguy]

Since this is a recent thread I have a question about blocking diodes. I do not plan on making any changes in the near future to my equipment so only interested in my blocking diode question below. I seem to remember a recent post that Mike90250 responded to on a similar question. I'm a retired EE so get the I and V thing!

I have several panels in a small off-grid system. Non-MPPT controller. All panels in parallel. Especially this time of year (low sun, palm trees in neighbor's yards, etc) I cannot prevent shade from impacting my panels and different ones at different times of the day. I have more than enough power to run the loads I want to run but am concerned about possible damage to panels in shade. I think Mike had mentioned that currents try to force their way in (path of least resistance) and eventually will burn out the bypass diodes. Thus, my question is (and yes, loss of a few watts is ok) should I be running blocking diodes on each of my panels?

Thanks in advance...

[Mike90250]

Blocking diodes are only sized large enough to support temporary operation. PV panels are supposed to be placed in full sun. If one panel in an array is shaded, depending on the size of the array, the shaded panel will throttle the entire array, or be burned out ( by the functioning panels exceeding the reverse voltage of the P-N junctions that make up a PV panel) So Bypass Diodes came to be, to allow damaging power to not smoke the shaded panel. However, the small, inexpensive diodes supplied with panels, eventually fail from stress/heat, so there exists a market for replacements.

Blocking Diodes serve a different function than bypass diodes. They Block the slow discharge of the batteries at nightime, from leakage through the P-N junctions in the PV array. All modern charge controllers provide this function and blocking diodes are no longer needed.