Testing Solar Panels

[KeithB]

I have 9 solar panels on the roof of the caravan build in my garage. Each will be connected individually to a bus bar.  Is there any way I can shine some kind of light onto each panel to test them in turn? What kind of light should I use?
I'd like to test everything before I put the ceiling lining in.
Keith

[BC66]

I have 9 solar panels on the roof of the caravan build in my garage. Each will be connected individually to a bus bar.  Is there any way I can shine some kind of light onto each panel to test them in turn? What kind of light should I use?
I'd like to test everything before I put the ceiling lining in.
Keith

The best way is with sunlight, not sure if a light will be enough.
There are two ways to test panels. Open circuit voltage test with a multimeter and amps test.
Connect the pos and neg wires together while in the sun. Connect an Amp Clamp to the wires and measure the amps produced.
Solar panels should have a sticker with the specs on the back, so compare your results with the specs.


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[tryagain]

As BC66 says, an amp clamp is the only easy way to test the actual output, you will need to hook them up to something to charge though. Thn put the clamp one of the wires from the panel and it will tell you the current going through it.

https://www.supercheapauto.com.au/p/sca-sca-clamp-meter---digital/343253.html

[KeithB]

Thanks BC and Tryagain. The problem is that I'd like to test them indoors, just to make sure the connections are all right, rather than testing for output. All I need to do is see some kind of voltage across the leads. Outdoors would be easy but where's the fun in that?
I can't get the caravan out of the garage until the build is finished. Hence the need to test for continuity beforehand.
If I could shine some kind of light onto each panel and see a voltage across the appropriate terminals, that would be good.
Keith

[BC66]

As BC66 says, an amp clamp is the only easy way to test the actual output, you will need to hook them up to something to charge though. Thn put the clamp one of the wires from the panel and it will tell you the current going through it.

https://www.supercheapauto.com.au/p/sca-sca-clamp-meter---digital/343253.html

No, testing the amps you don’t need to be connected to anything. I used to whole sale solar panels. Join the 2 wires together, face the sun and hook on the amp clamp. Same with OCV. Face the sun and hook up a multimeter to each wire, make sure they are not still connected to each other. The multimeter will read the voltage.
You only need to be connected to a battery if you are testing a solar controller


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[BC66]

May I suggest You should install these as well for protection
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com.au%2Fulk%2Fitm%2F253682809965
And use these instead of the bus bar
https://www.jaycar.com.au/solar-panel-y-cable-2-plug-to-1-socket-300mm/p/PS5112
As well as one of these inside the van
https://www.sparkydirect.com.au/c/247671/circuit-breaker---two-pole.html


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[KeithB]

BC thanks again for that.

All of this wiring is above the ceiling lining and the only access I will have after the lining goes in is through a little 150mm square ceiling hatch which will give access to all of the terminals at two bus bars, one for ground and the other for the positive leads. I'd like to be able to disconnect panels one at a time to investigate any future problems.  So there's not a lot of accessible room for extra stuff up there. Each lead will be labelled so that I can tell which panel it is from.

A fuse on each panel presents a similar problem. I have only an isolation switch prior to the MPPT regulator. So I guess I should put a big 100 amp breaker in there just in case. The system is 990 watts.

But surprise surprise! Looks like I'm getting about 0.5 volts off each panel just from the flouro lights in the garage. That's enough for me to test for continuity. It's the last thing I expected.

Thanks guys.
Keith

[tryagain]

No, testing the amps you don’t need to be connected to anything. I used to whole sale solar panels. Join the 2 wires together, face the sun and hook on the amp clamp. Same with OCV. Face the sun and hook up a multimeter to each wire, make sure they are not still connected to each other. The multimeter will read the voltage.
You only need to be connected to a battery if you are testing a solar controller

Something new learnt for the day, might test out the companion solar blanket later

[BC66]

Something new learnt for the day, might test out the companion solar blanket later

My 120watt 12 volt panel has an Open Circuit Voltage (ocv) of 22.03 volts
Rated current of 6.6 amps
But the short circuit current is 7.06 amps.

The short-circuit current is the current through the solar cell when the voltage across the solar cell is zero (i.e., when the solar cell is short circuited).


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[Fizzie]

If I could shine some kind of light onto each panel and see a voltage

Would a UV light, like the old Ray Lamps work

Might have to have a play later

[BC66]

An old school flood light might work


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[Herks]

An old school flood light might work


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Yes it will, the stronger the light the better, it won't give same output as direct sunlight but will give you proof of concept.