Short Circuit Amp (Isc) Measurement is Zero

[Snurd]

Hi All,

Forgive me if this question has been asked before. I've searched the archives and can't find a good answer.

I have a small 5 watt panel that will be used to help power a gate system. When I test the short circuit current amperage, or Isc, in bright sunlight I'm getting a zero reading, along with a negative sign beside it. The specs say .32A for this panel. I'm testing the panel disconnected from any battery source. The panel is producing 21V (VOC), so there surely has to be some current. What am I missing here? Any help appreciated.

Thanks!

[inetdog]

Hi All,

Forgive me if this question has been asked before. I've searched the archives and can't find a good answer.

I have a small 5 watt panel that will be used to help power a gate system. When I test the short circuit current amperage, or Isc, in bright sunlight I'm getting a zero reading, along with a negative sign beside it. The specs say .32A for this panel. I'm testing the panel disconnected from any battery source. The panel is producing 21V (VOC), so there surely has to be some current. What am I missing here? Any help appreciated.

Thanks!

Either you are not using your ammeter correctly (or internal fuse is blown) or the panel is defective. A mostly broken cell could put out some voltage but no current. (Should I presume you are testing outside in bright sunlight with the panel aimed at the sun?)A 20V battery in series with a 20K resistor would put out 20V but only 1ma of current. A similar thing could be happening inside the panel.

[corazon]

maybe your ammeter is broken,

i want to ask too, about Isc, at bright sunlight my solar panel (100WP), my panel produces Isc arround 7 Amps while the panel label listed only 5.45 Isc. How did it happen?

[inetdog]

maybe your ammeter is broken,

i want to ask too, about Isc, at bright sunlight my solar panel (100WP), my panel produces Isc arround 7 Amps while the panel label listed only 5.45 Isc. How did it happen?

The panel is better than its rating. It happens sometimes.
Also in some partially cloudy sky situations the panel can get direct light through a hole in the clouds and additional light diffracted through the edges of the hole.
Also the incoming sunlight is more intense at high altitude.

[Snurd]

Thanks for the suggestion to check the meter...

Since the voltage was reading correctly, it never occurred to me that the ammeter could be bad.

I borrowed another meter just now and the readings look good. Oh well, something new every day!

Thanks again for the help...

[Sunking]

Hi All,

Forgive me if this question has been asked before. I've searched the archives and can't find a good answer.

You did not look long or hard. If you had you would have found this Sticky.

I agree with Dave, You either do not know what you are doing, or have a bad panel.