Testing solar panel output.

Do a Google search on solar panel test's.

This is of the first site I found:-
To test a used solar panel, set your voltmeter to DC volts, and measure across the + and - terminals of the panel. This is called the "open-circuit voltage." A 12 volt panel should show about 21 volts in full sun. Panels designed to be connected in sets of 4 (4 panels in series) will show 4 to 5 volts. If your meter can measure DC amperes, set it for this (on a high enough range so your meter won't go up in smoke) and connect it between the + and - terminals in full sun. This measurement is called the short circuit current, and is how much current you can expect from the panels. For a 12 volt panel, multiply your current by 17 volts to get watts. (17 volts is the rated voltage of most 12 volt panels.)

Glen.

Hi Spinifex

What you did was correct. Amp meter straight across the output.

The aim is to measure the output current in the absence of a regulator. This will give you the maximum current that the pannel will deliver.

The opencircuit voltage has little bearing.

Redeye

These panel ratings relate to two different test - you do a test EITHER at open circuit OR at short circuit.

With a short circuit, the voltage output will, by definition be zero.

Unlike a battery, a solar panel is a constant current source. Whether you load it down to 15 volts or down to 0 volts, the current doesn't change a lot.

Hi
this could be of help as well

This is an interesting article on solar panel charging on connecting up properly

Site Link

Greenant

Hi Spinifex

I know you are testing the panel, I hope you have a regulator to fit when you are done. Don't connect the panel direct to the battery with no regulator and don't short circuit the panel when it is connected to a regulator and battery.

Also follow the warnings on the panel. DC current is dangerous when you have a solar grid.

Just want to keep you safe.

Regards Derek

Thanks for the replies

I can see now that my solar panels are OK. I was struggling with the concept of something providing amps but at zero volts. But as I was testing the current with a dead short I guess the short has removed the potential in the circuit.

Sorry if my terminology isn’t quite right, don’t have an electrical background.

So the 0.6 volt could indicate that there are diodes in the junction box, I always wondered if they were there.

Regards
Spinifex