I finally tore apart the panels and got rid of the blinking LED circuit. I hooked up one of my panels and read about 10V coming off. The other panel, in the exact same position from the light (an overhead incadescent 60 watt) was reading 2 Volts ! Why such a huge difference?
One panel was showing 10 V reading while the other 2 V, same distance from the light. When I brought the 10V panel closer to the light the voltage went up to close to 20V. When I brought the 2V panel closer to the light the voltage also went up, maybe to about 9 or 10 V. I am sure in direct sunlight they will both be up close to 20V, however I am surprised by the difference at the lower light levels.
Also one of the wires attached to the back of the panel fell off, I noticed it was soldered with a "blob" to the back of the panel. Didn't look like it was connected to anything, just splatted against the back of the glass on the panel. Perhaps I am not bridging to the proper layer or the solar panel it is shorting itself somewhere.
Anyone have any ideas?
The back of the panel has a black film which looks to be glued down. When I peel it off, and then rub away the glue layer, I see a silvery finish. If I rub this with sandpaper or scratch it nicely it will go right through to the glass and I can see right through. So I assume the silver finish is the amorphous silicon layer on the glass which is what I need to solder to.
I don't think it is my solder job, since I tried the voltmeter probe directly without solder to many other places on the back of the panel and got the same readings. If it was my connection or the layer I was connecting to, I assume it would have changed the voltage reading as I moved my probe around on the back. It was always the same.
So could there be a "short" in my panel causing this?
One more question, what are the lines visible when looking at the solar panel? There are no obvious wires there, it looks like it is just a gap in the silvery part... because when I peeled back the black backing layer from my panel and looked through, the lines correspond to the areas I could see through the glass clearly, whereas the other part of the panels still looked dark (I assume due to the silvery film and silicon layer stuck on the back of the glass).