I have a panel with a bad cell

[thehandyman]

Hi,


I got about 500 watts of solar panels given to me. One of them is a Sharp 36V panel. My boss who gave them to me said a guy gave it to him because it didn't test to spec. But it still had good out put.

He said it charged his batteries fine.

Looking at it, there is one cell under the glass that is discolored behind the EVA. I found out why... There is a burn/wear mark that goes *through* the EVA and the cell itself. I can see light all the way through the hole from the back of the cell.

I want to know how to bypass this cell. I know it will leave me with a half volt less output and a fractional amount of current. But I think the cell may be damaged and not allowing full power output. Do I just bridge the connections from the upper, and lower cell in relation? I will seal up what I do.

The cell:



And the hole:

[Mike90250]

If you are only 1/2 volt low, and your amps are 90% of nameplate (in summer sun, crystal clear sky) I'd not do a thing to it. Trying to dig out the tab wire, soldering it, and sealing it up afterwards, is likely to kill it over time. When you loose enough output that it's no good to you anymore, dig into it.

Always a chance you can call the warranty folks about it.

[bcroe]

One of them is a Sharp 36V panel. My boss who gave them to me said a guy gave it to him because it didn't test to spec. But it still had good out put.

Looking at it, there is one cell under the glass that is discolored behind the EVA. I found out why... There is a burn/wear mark that goes *through* the EVA and the cell itself. I can see light all the way through the hole from the back of the cell.

I want to know how to bypass this cell. I know it will leave me with a half volt less output and a fractional amount of current. But I think the cell may be damaged and not allowing full power output. Do I just bridge the connections from the upper, and lower cell in relation? I will seal up what I do.

You might want to test that the cell is really the problem. I used an infrared temp gauge to find
one here. At top of the picture. I'd get the panel in good sun for max current, and full load most
easily by shorting the panel. Good chance a bad cell will read a lot higher temp, mine did.

As to fixing, you'd need to at least short over the cell. Never tried that on such a panel. But where
the tabbing comes up from the back of a cell and goes on top of the next, a small hole would allow
shorting the jumper with the next top trace on the bad cell. For the 2 tabbing runs. Bruce Roe