I'm embarrassed to ask..... but,

[Tagg]

The new kid here again...

I done got burned on two used 5 watt panels on ebay.

(stated no return from seller... as is)

So I have two panels that put out 18 volts

and between 20 to 30 ma (far cry from 5W) ya think.

Is it possible to put some cells in parallel to get

a bunch of amps and then connect it to an 18 volt

panel in parallel ?

(I have a bunch of .5V @ .250ma cells)

In short:

18V with 20ma connected parallel to .5V with 2 Amp = what

aprox 18 volts at aprox 2 amps

See why I'm embarrased `(-_-)`

[commanda]

Assuming that the panels were once 5 watts, I'd hazard a guess and say that one cell has gone open. I'd be ripping it apart, finding the dud cell, and shorting it out. I know it defeats the factory sealing, but it's better than a wall ornament, because they don't make very good boat anchors :-)

Amanda

[Tagg]

Thanks... I was thinking about doing that,

but it may not be possible.

They are fairly old and sealed over the cells.

I don't think that the seller knows how to read

a testing meter. Both panels read about the same.

This link "may" take you there for a look.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5774300960

Thanks, Marlin

[pyrocasto]

Well, first off, I would have been a little skeptical about them. The seller has no feedback, and says he doesnt take credit cards, even through paypal. If that's true, he shouldnt have Paypal as one of his accepted methods of paying...

Though, he says they are in good working order, and give the specs that you are not getting. If you are testing them on a clear sunny day, and still getting that bad, I would email him, and Ebay if he does not respond. Get your money back.

Good working order does not mean 1/10th the original specs...

good luck,

[jimjjnn]

I would contact Solarex and find out if still under Warranty. Most maufacturers have a warrantee that says they will replace if more than 10% output is lost. These are usually a 10-25 year warrantee.

Not sure if your module would qualify tho.

[dconn]

Are you sure you are only getting 20 - 30ma per panel?  How are you measuring it - with a ammeter between the panel and a 12V battery?

Derek

[Tagg]

I think that the kid realized that ".27" isn't the

same as ".027" on his amp meter and removed the other

one I saw up for auction.

I think that since he claims to have 200 of them, they

were hooked "all" togeather before.

Live and learn. I will contact him tonight to see if I

get a reply. If I have to leave BAD feedback on him,

well... then so be it.

I tested two others that I have at the same time,

and they were fine, actually higher than the specs,

About time we get some sun up here in Minnesota.

Since I got them so cheep, I am still wondering if I can

rig .5 volts @ 2 amps with 18 volts @.02 in parallel

and end up with something.

The two bad panels hooked togeather wouldn't even give

me one watt. but if it's possible to use the established

voltage in conjunction with some amps I put togeather,

that would be OK.

Beats the hassel of sending them back, complaining to ebay

etc...

Any thoughts on .5 volts @ 2 amps with 18 volts @.02 amps in parallel?

Would I have anything? (it would save me building and testing it)

Or am I dreaming....Thanks, Marlin

[Tagg]

Oops...how'd dat happen....duplicate post

I am testing with amp meter just between the + and -

leads in the panels

[Tagg]

I just checked, and the oher panel he had up for

auntion was won without reserve being met.

Winner must have gotten it with the

"second chance" option like I did.

They also left positive feedback...hmmm

[Psycogeek]

"These solar panel are in good working "  = fraud.

you can send them back, and get PAYPAL to return your funds, AS-IS or NOT.

it probably is not worth it, nor is getting a NEG yourself in your feedback, but it is totally possible to aquire your funds back, just so you know.

[Experimental]

         Thats a shame Tagg -- but if the guy is selling junk, it won,t take long to end his ebay career !!

BUT, I certainly would contact him and complain -- if that dosen,t work, contact ebay ... When it comes to batteries, and solar panels though -- I buy new , as I just can,t "afford" the pain and hassel, not to !!   Best of luck to you, Bill H..

[Tagg]

Thanks to all of you !!!

My mind is to boggeled right now to even think.

In my first post I mentioned an old shed that

I was going to use to house the batteries.

Well... while digging around in the basement of it

(found a hidden container)

I discovered some old botteles of what appear to

be some very old nitro. I need a drink or 20.

And no, I'm not kidding. Just waiting for the athorities

to do their thing. I live on the iron range mining area,

so it's quite possible.

Sure hope I'm wrong !

Tagg...shaking in his boots

[Tom in NH]

My condolences. Sometimes you get lemons when you hope for lemonade. You pose an interesting question about paralleling your cells together. I've never tried paralleling 18v to .5v. My guess is you'll get close to the same output as your good cells (i.e. .5v@.25amp) Try it just for kicks and let us know the results. But don't bother trying it for productivity's sake. The output of your dud panels is so miniscule, it will not contribute significantly. --Tom

[pyrocasto]

You mentioned paralleling them, not a good thing.

18v @ .02 amps + .5 v @ 2 amps = .5 volts @ 2.02 amps I believe.

[wpowokal]

Also a silly question but you do have your metre set to DC not AC volts?

allan

[crag]

Ebay has buyer protection through SafeHarbor up to ~$200 (maybe more now), so it doesn't matter if it was Paypal (although they would've held his account) if it was fraud.  

[Tagg]

Well....{Tagg still scratching his head} Nothing went 'boom'

in the night, so back to the drawing board.

(bomb squad don't do weekends...go figure)

Chris- But where did those 18 volts go? I'm prob wrong,

but I think they will still be there? (somewhere)??

Tom- If the sun ever comes back out up here.....gerrrr

I think I will take two cells .5V @ .250ma and hook togeather

in series. that will give me 1V @ 250ma ) hook in parallel

with one of the 18V @ 20ma panel.

  I've got 40 of the .5V@250ma cells, but will need most of

them in the 36 string I'm going to build [+ or -].

(I don't wan't to re-solder...hence the series meathod)

I will let you all know what the heck happens.

Allan- No question is ever a silly one. {unless its never asked}

I don't think I would get a reading at all if it was on AC, but I will

have to try that and see.

  Its a new meter with a new operator(me). I've done many

readings in various light conditions on cells and the two

good panels I've got. (I've done dumb things in my day though).

The 2 panels were only $12.25 each plus $12 shipping. ($36.50 total)

So I will prob just chalk-it-up as a lesson learned.

But think of it this way, if I hook them togeather, I'll have

twice the power!!! [ 0+0=0 or 0X2=0 ] Come to think of it, two

nails stuck in a potato would give me more power...lol

Marlin...

[ghurd]

You may try to open the black box on the back.

Saw some similar that with bad connections in the box.

Not easy to get into, but got some of them working.

But have to wonder why he is not listing more if he has 200+ of them.

Maybe he only tested a few, and you just got lucky getting 2 bad ones?

G-

[Tagg]

Thats an idea ghurd.

Just looked (its in front on these) and it looks

pretty sealed up. But maby...

Chris- you are right. Those 18 volts went off into

never-never land. I'm testing with cloudy conditions,

but I still can get a good enough reading to tell the

volts, and abit on amps.

Volts read 16 and went to .5 in parallel with one .5V@250ma

Commanda- Ya know, I might just be able to rip them suckers

appart after all. That would give me 72 more cells to play with.

They measure 2.25" x .75"

It does say on the back of panel:

P Max- 4.7 W

V oc-  20.9 V

I sc-  .31 A

I pmax- .28 A

     &

Will Produce:

P max- 3.4 W

I pmax- .23 A

But I get (across leads) 17.99V @ 20 to 30 ma

The panels are realy quite beat to hell, but I may be able

to cut the cells off in strips of 9.

I'll see if I can't mess with the little black box first...

Tagg...

[Tagg]

Also I sent this message through ebay to seller:

I'm not quite sure what you doing to test these panels.

I get a sc reading of 18 volts and between 20 to 30 ma.

Not 270 ma like you claimed in the auction.

At best... these panels can only produce less than 1/2 watt each.

I have not left ebay feedback yet. Waiting your reply and intensions

on correcting this situation.

[ghurd]

They may be OK!

Test them in FULL SUN. Clouds make a heck of a difference on amps.

And aimed right at the sun at high noon.

Not flat on the ground at 7:00.

And no shadows from fingers.

The Isc should be about 0.24A, even if they are 'really' old.

You can test the output better with a 68 ohm 5W resistor.

Maybe 5 or 6 at 12 ohm 1W resistors in series.

(Radio Shack- not cheap- but often convienient)

Straight accross the leads.

Check the volts, should be somewhere about 16V.

Or if you do it fast (under 1 second), might do it with 2 1w 33 ohm in series.

They show a 50 ohm, 10W as sometimes in store. Close enough. Maybe call the stores around you.  Part #271-133, $1.79.  The V should read maybe 11 to 13V, best guess.

Or a 5 pack of 22 ohm 1/2W, 4 in series. #271-1103, 99 cents. Maybe 16 to 18V.

If you can come up with like 50 to 82 ohms, series or parallel, with 2W, that should be good enough for a test.

A bulb won't work like that, because they change as they get hot.

You will never get them apart in whole cells.

G-

[Tagg]

You can test the output better with a 68 ohm 5W resistor.

Maybe 5 or 6 at 12 ohm 1W resistors in series.

(Radio Shack- not cheap- but often convienient)

Straight accross the leads.

You're loosing me on the resistor testing meathod.

I did test them in full sun at about 2:00'ish yesterday,

same as I test the others, (cells & panels)

They read 17.99 volts @ 0.02 amps

second one was 18.00 volts @ 0.03 amps

At the same time I tested another 5W panel that I got the

day before. It showed 22.(something) volts, (across leads)

and .570 amps. (good panel...wow)

---- specs for it are: Voc:22 & Isc:450mA ----

Also tested over 40 cells to pick out the best 36 (2 times).

So, I pretty sure I'm doing the testing correctly

But I have another idea too:

The face of these are a rubbery texture, and I could penetrate

it with a pin to test amps before the black box. If the box

is the problem, I would be able to cut away enough to just

bypass the box.......

But... Would I have to sever the leads into the box before

I tested it that way?

You can see all the tabbing / connecting bars through the face.

Marlin...

[Nando]

Too bad you have been burnt:

Give him a BAD REPORT clearly indicating why, this way he may not sell anymore of those cells.

When buying old or used panels, one needs to ask for the output voltage at full sun and the short circuit current -- including in the message how to do both measurements under full noon sun.

The panels will not be damage when going short circuit current and the only thing that you need is either an Analog or digital ammeter, IF THE SELLER says I do not have any DO NOT BUY ANY Panel.

I have repaired some, but the construction may allow how to remover the back or front to expose the cells and their connections -- shorting the output with the ammeter and starting shorting the outputs toward the center until the short circuit current disappears, then going from the opposite point toward where the short disappeared to find if you have one or more bad cells.

Good luck

Nando

[Nando]

The seller CLEARLY INDICATED THAT the panels were in good working condition, 20 Volts X 0.27 amps - 5 watts.

So present to him his statement THAT IS A LEGAL GUARANTEE

Nando

These solar panel are in good working , used condition. 20 volts X .27 amps - 5 watts. SOLAREX Model # MSX5L. Simple two wire hookup.Great for school projects, crafts. running small electric motors, charging batteries, or whatever !!  Get them quick, they will go fast !! New cost is $94.00 each.  OVER 200  available !!! Price is for one panel !!!!  I DO NOT ACCEPT CREDIT CARDS, THRU PAY-PAL OR NOT  

 

[ghurd]

Yes. Or is it no.

I can not say if the PVs are good.

You said 17.99V @ 0.02A.

But WHAT is the LOAD for testing?

I just tested a stepper motor.

At 51VDC and over 100ma.

At 12.9VDC into a battery it was 0.039A.

The first numbers with no load is 5.1W.

The REAL watts is 0.5031.

There is a place where the load

(knowing the resistance and the amps or the volts)

actually equals the power.

A perfectly good PV could have similar numbers to what you have given.

An example with just the PV and the meter.

PV to meter set to Vdc=1,000,000V.

PV to meter set to Adc=1,000,000A.

Either way, it is '0' watts made.

Watts is equal to amps X volts.

W=AxV (or P=IxV)

W=0A x 1,000,000V= 0 watts.

W=1,000,000A x 0V= 0 watts.

There must be a known load or all of the numbers are useless.

I would use a 12V battery at 12.6V connected to the PV, but I have some here.

Maybe connect it to your car battery and test the amps?

G-

[Tagg]

Sorry, as you know, I am just learning.

This last post has me realy confused now.

"But WHAT is the LOAD for testing?"

Just across the two leads on the panel, NO LOAD

"I just tested a stepper motor.

At 51VDC and over 100ma.

At 12.9VDC into a battery it was 0.039A.

The first numbers with no load is 5.1W.

The REAL watts is 0.5031."

So are you telling me that it's possible for this

panel to put out more power/wats under a load, than

what the readings are across the leade with no load?

Your stepper motor showed 51VDC @ 100mA = 5.1W

Now at 12.9VDC @ 39mA = 0.5031W

So... If the panel is 17.99V @ 20mA (across the leads)  now = .3598W

When its under a load and at 12.9 volts the watts could go up?

I don't think thats possible

Please correct me if I'm wrong

Marlin

[Tagg]

I agree... waiting for a reply from him to see what kind of seller/person he is. His reply to what I sent him (posted above) will determine what I do next.

[Tagg]

I should give him a chance to make it right

befor I report him or just leave BAD feedback.

I realy think he thought he was correct on

what he was listing the readings at, and he

prob knows he screwed-up big time.

I keep checking, no more have been listed.

Maby a partial refund is in order. etc...

Until then, I better not rip into these puppies.

Thanks Nando

Marlin