Solar Panels have Voltage but no Current Output.

[noelex 77]

Originally Posted by jseas

Can diodes in the junction box cause this?

No, they are bypass diodes.

[MBWhite]

Originally Posted by jseas

All cabling up to the mc4 connectors and pigtails going into the junction boxes have tested good. So it has to be either the connector, pigtail, diodes, or bad panel. I'm going to pull the panels and setup a test bench at home.


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First, to answer your original question on how most panels fail, it is usually a generalized slope downward where output gradually drops, so instead of getting 130 watts in full sun you'll get 100 watts, and a year or 3 later it is down to 90 watts, etc. So a generalized answer for your issue would be that it points to a bad connection, possibly caused by corrosion. It could still be a physical issue at the panel such as a crack in conducting foil, etc but you do not hear about those much, and I would doubt that it would hit 2 panels at the same time. That said, stuff happens so you can never know for certain without testing.

Are there any connections at all in the wiring run between the panels and the junction box? Was there any work at all done on your boat around the time you noticed your panels stopped working?

[jseas]

Thank you MBWHITE. That was what I had thought but could never find the exact info. I can't think of anything that had changed. I'll post something when I find out.


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[jseas]

Well it looks like both of my panels are bad. I measured at each panel's junction box for short circuit amperage and I get .00 and .03. After reading up on kyocera panels made from 1999 to 2000 it seems they had issues. I bought these used so no way to get them replaced. Looks like I'll shop for new panels. Leaning toward Renogy 100w panels. Probably not made as tough as the kyocera but they are a lot less weight on my davits.


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[socaldmax]

How long have you had them? Is there any chance that you can take them back? Seems like you were defrauded if they were defective when you bought them.

Please tell me that you tested them when you took possession of them.

[jseas]

I've only had them about a year. Unfortunately they came from ebay. Tested them when they arrived and got good 6 amps. The only thing I can figure is somehow I damaged them. I have blown a few fuses over the past year so maybe there was some back flow from other panels.


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[socaldmax]

Sorry to hear that!

Since they're shot, it wouldn't hurt to take a look at the connections between the box and the panel itself, maybe one or the other of the thin strips broke where you can get to it and fix it.

Good luck!

[jseas]

I assume those connections are under the pink looking epoxy in the photo?


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[socaldmax]

Originally Posted by jseas

I assume those connections are under the pink looking epoxy in the photo?


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I think so. You might have to do some careful digging. I saw some pics of panels where the guy had removed all of the connection boxes for some reason, and there were 2 thin tinned strips coming out of the panel backing right where the 2 inner set of terminal strips are.