lotust
Long Island NY
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Hey guys, I just bought a used Siemens solar panel off a craigslist seller. It seems to work great but I noticed that the date on the thing is 15-95 Im guessing the 15th day in 1995?
is this too old ? I thought these panels have a limited life? 20 years or so. the panel is putting out 17-19v on a rainy day. I ran a small handheld CB radio of it with no problem.. though it did not have the power to transmit that good (low batt warning light lit up)
- 2006 Jayco Jay Flight 27 BH.(paid cash :-)
2008 toyota tundra 5.7L w/tow Off road Pkg 4:30 gears (not paid off:-(
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The wife and our boxer(RIP Buster), Loving Camping!
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Hurricaner
Hurricane Utah
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Joined: 02/17/2007
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They will produce full output for 15 to 20 years but they will last much longer although a 75 watt panel might only provide 60 watts. That panel does not look like it has been out in the sun for that long so it might have years of life at full output.
Sam
Sam & Kari
Hurricane, Utah
2004 34' Damon Challenger 315
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djevans
Tennessee
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Joined: 03/24/2002
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The panel itself can last for 25 years, possibly more.
With regard to your radio, you might want to consider a regulator (charge controller of some sort) if you're going to run a 12v radio. When you're not transmitting the current consumption is much lower and the panel output voltage will go up, up to point that might damage your radio. The easiest thing to temporarily do is simply put the solar panel across a 12 v car battery or similar. That will hold the voltage down considerably on bright days.
Let us know if it provides the 22 volts (open circuit) on a sunny day. Then you'll know more about how it's really doing. On that bright sunny day, see if it's putting about 4 to 6 amps out to the battery...
Don . . . near 36.171N 086.784W, TN near here
WA4ZFN
2003 Fleetwood Revolution 40C - Saturn VUE
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Gdetrailer
PA
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Joined: 01/05/2007
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Panel visually looks like it is in good shape, nothing broken/cracked. You have an output so really the only thing to do now would be connecting to a battery with an ammeter to see how much current is being developed.
Solar panels will overtime degrade causing less current to develop so instead of 75W it might make 70W or there abouts. No big deal though.
If you connect it directly to a battery you should check to see if it has a blocking diode. If it doesn't directly connecting to a battery will drain the battery at night.
At 75W you should consider a charge controller for solar panels which will take the place of a blocking diode and protect your battery from overcharging.
One last thing, you are lucky to not have damaged your CB, this panel is rated to 22V, if it was a sunny day it could have easily burnt up the CB since the panel has no voltage regulation.
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lotust
Long Island NY
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thanks for the comments guys. Im going to test it tomorrow in full sun hopefully :-)
150$ is pretty cheap for this panel then right ? I have a chance to buy another from the guy.
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djevans
Tennessee
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I guess testing out OK it might be about right. It's still a 14 15 year old panel. On the other hand, it IS made by Siemens, a very good panel builder with lots of experience. I guess I would be checking it for "continuity of output." Some panels, when heated quite hot by the sun, might drop output or even open. But if it puts out 4 amps all day, I might buy several more having a specific application for them. I doubt you'd be able to touch a quality new panel for that price.
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lotust
Long Island NY
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djevans wrote:I guess testing out OK it might be about right. It's still a 14 15 year old panel. On the other hand, it IS made by Siemens, a very good panel builder with lots of experience. I guess I would be checking it for "continuity of output." Some panels, when heated quite hot by the sun, might drop output or even open. But if it puts out 4 amps all day, I might buy several more having a specific application for them. I doubt you'd be able to touch a quality new panel for that price.
Yeah I did notice that its pretty well made as you said. I was going to buy on off Ebay made in china. I have no doubts that this is a wekk made panel.
Edit: also how can I test for the amp output? Im using a friends Fluke meter. Do you know what I need to turn the knob too?
I think it looks like this one
http://gsmserver.com/newshop/images/large/Fluke_179_Digital_Multimeter.jpg
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djevans
Tennessee
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black on "COM" - red on "10A" - meter on the capitol "A" - set up like this, you can read up to 10 amps (typically it would tolerate a little bit more before blowing the fuse)
I seldom "short circuit" electrical sources, but it's done. The meter will handle the full output of the panel with room to spare. It should read a little higher than 4 amps, may read as high as 5 amps "directly across the leads" (hold it there only briefly)
NOTE: DON'T DO THIS on any other voltage source, ESPECIALLY NOT a vehicle starting battery or power company source - a solar panel is one exception to using a "current meter" directly across the power output leads - small aa batteries (or similar) might be another exception, but shorting them, runs them down very quickly)
Remember to also check the output voltage - you're expecting 22 volts on a bright sunny day with a decent meter (which you have)
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lotust
Long Island NY
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djevans wrote:black on "COM" - red on "10A" - meter on the capitol "A" - set up like this, you can read up to 10 amps (typically it would tolerate a little bit more before blowing the fuse)
I seldom "short circuit" electrical sources, but it's done. The meter will handle the full output of the panel with room to spare. It should read a little higher than 4 amps, may read as high as 5 amps "directly across the leads" (hold it there only briefly)
NOTE: DON'T DO THIS on any other voltage source, ESPECIALLY NOT a vehicle starting battery or power company source - a solar panel is one exception to using a "current meter" directly across the power output leads - small aa batteries (or similar) might be another exception, but shorting them, runs them down very quickly)
Remember to also check the output voltage - you're expecting 22 volts on a bright sunny day with a decent meter (which you have)
Thanks I did not have a nice sunny day before we left for camping. Were here now and I saw 13v inside the camper with the panel connected directly to 2 12v batteries. Thanks so much.
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mchero
Concord, NH
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Joined: 11/09/2004
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Grab the other panel, Great deal if it's in the same shape!
Mount both on the roof, install a charge controller and you hav a system that will keep your batteries up to full charge while in storage!
Robert McHenry
Concord, NH.
1993 Fleetwood 36' Pace Arrow
Cummins 8.3l Turbo 300hp (uprated)
Allison 3060 Trans
http://dieselrvowners.com
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