I have two 120 watt panels on my catamaran. They now only put out 6 volts.
What series of steps would you suggest to find the problem? They have worked
well for the past five years.

In article 6505f61907dfe@uwe, "ltkhbl" u25506@uwe wrote:

I have two 120 watt panels on my catamaran. They now only put out 6 volts.
What series of steps would you suggest to find the problem? They have worked
well for the past five years.


Find a Kid walking the dock, who knows more about electricity than you
do,and knows how to use a VOM, and pay him $10US to help you.........

"ltkhbl" u25506@uwe wrote in news:6505f61907dfe@uwe:

I have two 120 watt panels on my catamaran. They now only put out 6
volts. What series of steps would you suggest to find the problem?
They have worked well for the past five years.



Set them in the sun charging batteries. Touch each cell with your hand.
The ones that burn you, are working cells. The ones that don't and only
feel warmed by the sun, are dead, probably shorted.

When you say they "put out 6 volts", are you measuring this voltage with
the array disconnected? Open circuit in the sun should be around 18+
volts. You can't measure their voltage hooked to batteries, only their
charging current.

240 watts at 14V is a little less than 20A. Nice panels.

Look at the individual cells. Are they all turning brown from the
overheating? Brown cells will still produce electrons, but no where near
20A....probably 5 on panels that large.

My captain bought us a brand new solar panel, 120 watts like yours. He
sat it up on top of the old solar panel. Friends came aboard and they
all went sailing (without me..(c The boat heeled over, the new solar
panel slid over the side and is on the bottom of Charleston Harbor in
60' of water....somewhere. Sure glad I wasn't aboard. I'd have been
sick...



--
There's amazing intelligence in the Universe.
You can tell because none of them ever called Earth.

ltkhbl wrote:
I have two 120 watt panels on my catamaran. They now only put out 6 volts.
What series of steps would you suggest to find the problem? They have worked
well for the past five years.

Test each panel individually. From the Shell Solar panel instruction
book:

"Check the voltage of individual isolated modules . . . A reading 1/2
of the specified voltage indicates a short circuit of a bypass diode.
.. . [A good diode] will have resistance in one direction and an open
circuit in the reverse direction. Continuity in both directions
indicates a short circuit of the diode."

I think 5 years is the problem. Solar cells have a finite life. Buy new
ones.Five years is about end of life.
Steve

"ltkhbl" u25506@uwe wrote in message news:6505f61907dfe@uwe...
I have two 120 watt panels on my catamaran. They now only put out 6 volts.
What series of steps would you suggest to find the problem? They have
worked
well for the past five years.

Steve Lusardi wrote:
I think 5 years is the problem. Solar cells have a finite life. Buy new
ones.Five years is about end of life.

Except on all of them sold now, where there's a 25 year full
replacement warranty...

L8R

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