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It is important to test all the solar cells before constructing a solar panel,what type of tests should be preformed,and how 
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Did you try searching first? If you had you would of found this.MSEE, PE -
Thank you
Yes Sunking i have searched and i like to choose the best way to do it .
Thank you for your verry useful reply it was helpful.Comment
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This is what I built to test 6" X 6" cells, works pretty well on 3 X 6 also. Puts a heavy load
on the cell and checks all 4 leads individually for a weak spot. This one for sale. Bruce RoeComment
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testing solar cells
Thanks bcroe for you offer but i am from Egypt and it will cost me too much to bay and ship your testing instrument,if you can send me the design and how to use i will be grateful.
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testing solar cells
Is it a must to test the solar cells under direct sun light or i can use artificial light as well ?
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I used a regular 100W bulb, make sure the bulb and each cell is in the same position for a meaningful current reading (make a jig up).DemComment
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Direct sunlight. Solar panels are current sources, and current output is directly proportional to the amount of sunlight striking its surface. Artificial light can be used to test Voc, but useless to test current.MSEE, PEComment
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Agreed; that is part of the object of my test unit. I used a 100W spot lightOriginally posted by FunGas
to get most of the light heading the right direction. The dummy load was chosen
so that the cell would not quite reach Vmp; otherwise good and somewhat marginal
cells would all put out almost the same voltage (with a fixed load). Current was
around 75% of rating on a good cell. Bruce RoeComment
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Dummy Load on a ISC test? Huh?
You cannot and do not want to use any load resistance doing Isc test. Isc is Current Short Circuit test where the output leads of the panel are connected to each other or Shorted Out. To test it all you do is short the panel or cell out with a DVM and read the current.MSEE, PEComment
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Power test
That is all true, if you are running your most basic Voc and Isc tests. I chose to run
a POWER test, which can be difficult to set up on a panel & varying sun. But not so
difficult here with one cell and controlled (if somewhat reduced) light.
My cells had 2 leads on EACH face, any one of which could have problems if there is a
crack. In addition there is the issue of overall total cell performance. I connected one
end of a a 0.05 ohm 5 watt resistor to each of 4 leads. The other end of all 4 resistors
were all shorted together with a heavy (dual 12 gauge) wire. This presents a 0.05 ohm
load overall to the cell. So if it put out 10 amps, the voltage would reach 0.5V. The 8A
cell will never put out that much, so I would see voltages around 0.4 volts. This would
vary so I could weed out poor performers.
IN ADDITION, I have a 5 position switch which connects the voltmeter to the whole cell
(averaged through some 100 ohm resistors), or to ONE of the 4 resistors at a time. The
voltmeter wires were connected by a dedicated pair directly to one of the resistors at a
time, to avoid any loop shifts (Kelvin connection). IF ONE of the cell output lead's current
was reduced significantly from the other 3, it could indicate a flaw in the cell current
paths there. It was necessary to switch thru the 5 positions pretty quickly, before the
lamp heated the cell and numbers started drifting. Bruce RoeComment
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Bruce DIY cannot measure Imp, that can only be done in a Lab. Best one can do is find out which cells are stronger by shorting out the cell. Adding a resistor just reduces the current to some unknown value and does not gain you anything.MSEE, PEComment
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Right, it doesn't produce lab standard results. INSTEAD, it locates a fault feeding one of
the leads, and allows matching a bunch of cells, or determining the best ones, to make
up a DIY panel. It does so under conditions much closer to actual operation, than the
Voc or Isc points. That IS where we are ultimately going. A useful DIY function, not
suitable for commercial use as defined. Bruce RoeComment
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design or photos
Bruce can you please attach the design or photos of your jig i will be very gratefulComment
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