Trying to match solar panel

[soon2befree]

I have a 180 watt 36 volt panel installed. I want to add 2nd matching panel but I cannot find same rated panel. I do not know who made original panel. Any help will be appreciated.

[arcaguy]

A picture would be worth a thousand words in this case. I might talk to Santan Solar or go to mobile-solarpower.com. At mobile-solarpower,com click on "more' and go to the message board. Post a picture of your panel. front and back if you can, someone there should recognize it. Good luck.



https://santansolar.com/
https://www.mobile-solarpower.com/

[SteveJ.]

If mounting the panels parallel, voltage is critical, amperage is not, but should be close, if possible.

[DavidEM]

I doubt it is a 36V panel. Solar panels are made in two voltages typically- 12V and 24V nominally. I say nominally because solar panels can put out a wide variation in voltage depending on the load applied.

12V nominal panels have a Voc (open circuit voltage, ie no load) of about 21V. They have a Vmp (maximum power point voltage) of about 17V. 24V nominal panels double these voltages.

So even if you have no data on your existing panel, you can measure the Voc voltage and see what you have. Disconnect the output leads and with the panel pointed as close to directly into the sun as you can get, measure the output voltage with a multimeter. Nothing but the multimeter should be connected.

Then once you know which nominal voltage panel you have, get another one like it. The voltages don't have to be precise, within a few volts will be fine.

Also, what kind of controller do you have? If you have a PWM controller then your panel is almost certainly a nominal 12V panel.

David

[twinboat]

Originally Posted by DavidEM

I doubt it is a 36V panel. Solar panels are made in two voltages typically- 12V and 24V nominally. I say nominally because solar panels can put out a wide variation in voltage depending on the load applied.

12V nominal panels have a Voc (open circuit voltage, ie no load) of about 21V. They have a Vmp (maximum power point voltage) of about 17V. 24V nominal panels double these voltages.

So even if you have no data on your existing panel, you can measure the Voc voltage and see what you have. Disconnect the output leads and with the panel pointed as close to directly into the sun as you can get, measure the output voltage with a multimeter. Nothing but the multimeter should be connected.

Then once you know which nominal voltage panel you have, get another one like it. The voltages don't have to be precise, within a few volts will be fine.

Also, what kind of controller do you have? If you have a PWM controller then your panel is almost certainly a nominal 12V panel.

David

36 volt panels were very popular for grid tie house installation.

I had 3 170 watt 36 volt panels on my boat with a MPPT controller.

Now days, you'll find 48 and 56 volt panels out there.

[DavidEM]

Originally Posted by twinboat

36 volt panels were very popular for grid tie house installation.

I had 3 170 watt 36 volt panels on my boat with a MPPT controller.

Now days, you'll find 48 and 56 volt panels out there.

Ok, then the OP should measure the Voc and get a panel that matches. I suspect it won't be 3X the Voc of a 12V panel because it probably has less than 3X the number of cells that a 12V panel uses.

David

[harryn]

Is there any chance that your panel is one that has a Vmp = 36 volts?

The same exact panel is often colloquially called a "24 volt panel".

If the panels will be wired in parallel, then the Vmp should be close, but doesn't need to be exactly the same.

The wattage does not need to match and in fact might not because companies are constantly trying to increase the wattage.

Many companies make panels like this, such as newpowa, grape, solarland, etc.

Just as an example, this is a solarland - similar to what I use on my solar test stand at my van electrical shop. It is optimized for overcast conditions:

https://unboundsolar.com/9433259/sol...lt-solar-panel

Here is a mono panel that is 190 watts from another on line retailer:

https://www.solar-electric.com/solar...lar-panel.html


and here is newpowa with the same Vmp in 210 watts.

You will need to check yourself about dimensions / mounting, etc but this should get you started:

https://www.newpowa.com/collections/...4v-solar-panel

The photo is my test stand and also it supplies a lot of the power that I use since I am off grid. The blue panels are poly and are better for capturing very poor lighting. The black ones are mono and are better for full sun conditions.