Cells with low power

[labtek]

Hello to the group and good day. I recently received a batch of 3x6 inch cells from a supplier from EBay. I had ordered from this dealer before with good results. After opening the package from the latest batch, at least 4 of the 40 cells were broken beyond repair. Of the remaining cells after tabbing them, there was a wide variation of voltages from 1 cell to the next. The cells also seemed a lot more brittle and fragile than the first batch. By the time I removed the lowest voltage cells and replacing them and not using the broken ones, I didn't have enough cells left to complete the panel. I thought that I should have producing cells if I was going to the bother of mounting them into the panel. The supplier advises that he will replace the cells with the next batch I order but I don't want any more low quality cells.

Is it routine to have this variation in cells from the same supplier? Is there a way to ensure that the cells I order are good quality before ordering and paying for them.

I happily defer to advice from those with more experience than me. Thanks in advance.

[SunEagle]

Hello to the group and good day. I recently received a batch of 3x6 inch cells from a supplier from EBay. I had ordered from this dealer before with good results. After opening the package from the latest batch, at least 4 of the 40 cells were broken beyond repair. Of the remaining cells after tabbing them, there was a wide variation of voltages from 1 cell to the next. The cells also seemed a lot more brittle and fragile than the first batch. By the time I removed the lowest voltage cells and replacing them and not using the broken ones, I didn't have enough cells left to complete the panel. I thought that I should have producing cells if I was going to the bother of mounting them into the panel. The supplier advises that he will replace the cells with the next batch I order but I don't want any more low quality cells.

Is it routine to have this variation in cells from the same supplier? Is there a way to ensure that the cells I order are good quality before ordering and paying for them.

I happily defer to advice from those with more experience than me. Thanks in advance.

Those type of cells being sold on EBay are really discards from the PV panel industry. They fall below the specification for a Class A cell and are sold to others for scrap value. You may find that they are cheap but that means they really are "cheap". There will be no consistency from one cell to another let alone from one batch than another.

If you want to experiment with building a solar panel then those cells will be just fine for that. But don't expect them to last long or be consistent with their current/voltage output because they are nothing but junk. The best way to spend your money is to purchase panels that are already made.

Sorry if I have told you what you didn't want to hear but those are the facts.

[labtek]

Those type of cells being sold on EBay are really discards from the PV panel industry. They fall below the specification for a Class A cell and are sold to others for scrap value. You may find that they are cheap but that means they really are "cheap". There will be no consistency from one cell to another let alone from one batch than another.

If you want to experiment with building a solar panel then those cells will be just fine for that. But don't expect them to last long or be consistent with their current/voltage output because they are nothing but junk. The best way to spend your money is to purchase panels that are already made.

Sorry if I have told you what you didn't want to hear but those are the facts.

No real surprise to hear that but since I presumed that this forum is "building homemade solar panels" then at least the possibility exists of buying the cells needed to build aforementioned solar panel. My experience on EBay is that if one carefully looks at feedback ratings and other telltale guideposts, it is theoretically possible to obtain reasonable value. At present, I am in the experimental phase but plan to expand into a more practical application since I believe that the future is bright for home PV (pardon the expression).

[SunEagle]

[
QUOTE=SunEagle;66936]Those type of cells being sold on EBay are really discards from the PV panel industry. They fall below the specification for a Class A cell and are sold to others for scrap value. You may find that they are cheap but that means they really are "cheap". There will be no consistency from one cell to another let alone from one batch than another.

If you want to experiment with building a solar panel then those cells will be just fine for that. But don't expect them to last long or be consistent with their current/voltage output because they are nothing but junk. The best way to spend your money is to purchase panels that are already made.

Sorry if I have told you what you didn't want to hear but those are the facts.[/QUOTE


No real surprise to hear that but since I presumed that this forum is "building homemade solar panels" then at least the possibility exists of buying the cells needed to build aforementioned solar panel. My experience on EBay is that if one carefully looks at feedback ratings and other telltale guideposts, it is theoretically possible to obtain reasonable value. At present, I am in the experimental phase but plan to expand into a more practical application since I believe that the future is bright for home PV (pardon the expression).

I understand. I hope you enjoy the experimentation.

As for the Ebay source, even the sellers that provide good material and get great feedback can't guarantee that the single PV cells they provide will be consistent from one sale to another. Especially if they get them in big lump shipments. These cells did not meet the MFG specifications to go into their completed PV Panel. That is why they got rid of them and sold as "seconds" or "thirds". They are not made properly and will break or fail to produce consistently. I wouldn't build a system out of them because they will not provide you with consistent power.

As I stated. Enjoy the experiment but don't hang you hat on a Class A product.

[russ]

No real surprise to hear that but since I presumed that this forum is "building homemade solar panels" then at least the possibility exists of buying the cells needed to build aforementioned solar panel.lNot really - most agree that they are an interesting science project only.

My experience on EBay is that if one carefully looks at feedback ratings and other telltale guideposts, it is theoretically possible to obtain reasonable value. Theoritically many things are possible. Some of the people posting on ebay write their own reviews

At present, I am in the experimental phase but plan to expand into a more practical application since I believe that the future is bright for home PV (pardon the expression). More of a joke than a pun

Comments in bold

[PNjunction]

Is it routine to have this variation in cells from the same supplier? Is there a way to ensure that the cells I order are good quality before ordering and paying for them.

Just accept that fact that you are dealing with cells that don't pass the STC test. Things like microcracks, leakage, and the fact that most reject cells don't get the ARC anti-reflective-coating applied to them if they don't pass the test. Those that do go to manufacturers.

I've built my own panels and it was a lot of fun - as long as you are realistic about the quality of the cells.

I see a lot of homebrew encapsulation methods, but very few on finding a proper way to apply a homemade ARC coating - even if the underlying cells don't pass the STC test initially.

[Mike90250]

There are no "prime" cells on ebay. Just floor sweepings.

At home with a meter, I can measure Volts and Amps from the cells. There are a dozen other tests for cells I can't do at home, and those are the ones that help determine the longevity of the cells (and the panels they are in)