Due diligence with grey market / B grade cells

[Dzl]

Many people caution against buying grey market cells off Alibaba or Aliexpress. Many of us will do so anyways (trading potential cost savings for higher risk).

For those of us looking at grey market cells (i.e. sold by Chinese resellers, old OEM stock, B grade, no QR code, etc) from semi-reputable sellers, what information and test results should we be looking for (before we buy) to minimize the risk.

I know cells should be "well matched." I believe this means matched in 'capacity' (or voltage(?)) and 'internal resistance,' are these both things reputable resellers would test? Are there other ways in which cells should be 'matched'?

What would you/should I ask sellers?

 

[FilterGuy]

The primary thing you are looking for is well matched capacity. Internal resistance matching is important, but it is harder to measure. For the most part if your cells are well matched by capacity, they will be well matched in internal resistance.

Matching voltage is meaningless. You can take two totally different and unmatched cells and charge them to the same voltage. However, if you receive cells with wildly different voltages, it probably means no attempt at match testing was made. (If they did match testing, their test procedure would probably leave all the cells at about the same voltage)

> What would you/should I ask sellers?
This is a tricky one. By their very nature, these sellers are likely to be less knowledgeable and likely to be less honest. Ironically, if they answer a question in a way that sounds bad, it is probably a sign they are being honest with you. However, if they answer a question in a way that sounds good... you still don't know what to believe.

Having said that, it does not hurt to ask questions. Here are a few:
* Are these new or used Cells?
* Do you match them before you ship them? How do you do your match testing?
* Are these grade A or Grade B/C cells?
* Who is the manufacturer of the cells?
* What is your return policy?

If you buy any, let us know what your experience is (good or bad).

 

[FilterGuy]

It would be great is if one of the reputable cell manufactures sold their grade b cells and told you why they were grade B.

If I know what I am getting:
* I would happily take a discount on a batch of cells that were cosmetically imperfect but otherwise fine and well matched.
* I would happily take a discount on a batch of new cells that were slightly below spec capacity but were otherwise fine and well matched.

It would be fairly straight forward for the manufacturer to 'bin' their grade B cells based on how they failed in testing. However, it is certainly easier and may be just as profitable to sell the Grade B cells in batch to the resellers.

The key here is knowing what you are getting. By the time the grade B cells get to a re-seller, the level of trust drops off pretty dramatically.

 

[Dzl]

It would be great is if one of the reputable cell manufactures sold their grade b cells and told you why they were grade B.

Yeah, this is my thinking too. Ideally, the manufactures themselves would DESTROY grade C cells, and categorize and sell grade B cells as make it clear that they are B grade and make it clear why they are categorized as grade B. If they are worried about their reputation they could do as the cell companies do and create official 'off brands' with their own brand identity so as not to harm their reputation or confuse consumers.

This is a tricky one. By their very nature, these sellers are likely to be less knowledgeable and likely to be less honest. Ironically, if they answer a question in a way that sounds bad, it is probably a sign they are being honest with you. However, if they answer a question in a way that sounds good... you still don't know what to believe.

If I know what I am getting:
* I would happily take a discount on a batch of cells that were cosmetically imperfect but otherwise fine and well matched.
* I would happily take a discount on a batch of new cells that were slightly below spec capacity but were otherwise fine and well matched.

It would be fairly straight forward for the manufacturer to 'bin' their grade B cells based on how they failed in testing. However, it is certainly easier and may be just as profitable to sell the Grade B cells in batch to the resellers.

The key here is knowing what you are getting. By the time the grade B cells get to a re-seller, the level of trust drops off pretty dramatically.

Yeah, this is what I'm going through right now. I'm trying to convince the salesperson to just be straight with me and give me an objective description of the cell, and that based on the price I don't expect them to be perfect, but I do expect them to be healthy and well matched. I, like you, would happily buy cosmetically imperfect cells, or cells that are well matched but didn't meet capacity specs, or are OEM overstock that was stored properly, if the price reflects this.

It feels like pulling teeth with chinese resellers to get objective direct information about cells. When they really don't need to try so hard to avoid acknowledging imperfections when the price reflects this.

If you buy any, let us know what your experience is (good or bad).

Will Do!

 

[Dzl]

The primary thing you are looking for is well matched capacity. Internal resistance matching is important, but it is harder to measure. For the most part if your cells are well matched by capacity, they will be well matched in internal resistance.
...
Having said that, it does not hurt to ask questions. Here are a few:
* Are these new or used Cells?
* Do you match them before you ship them? How do you do your match testing?
* Are these grade A or Grade B/C cells?
* Who is the manufacturer of the cells?
* What is your return policy?

If you buy any, let us know what your experience is (good or bad).

Thank you, this is super helpful. So a capacity test is the most important and the most likely test they will have done?

 

[FilterGuy]

Thank you, this is super helpful. So a capacity test is the most important and the most likely test they will have done?

Capacity testing is certainly what I would focus on.

I really don't know what tests they are most likely to do. There are a lot of possibilities

1. actually do a capacity test to ensure well matched cells. It seems unlikely they would test each order, but they might pre-test and bin the batteries based on capacity.
2. grab the cells out of bins of cells that were (supposedly) matched by their supplier
3. Just ship whatever they have.
4. Test voltage and ship them to you claiming they are matched
5. Charge them all to the same voltage hoping you think they are matched

If they tell you they ship matched cells, I would hope that it would be at least the 1st or second

 

[CoryBaker]

Well I did get my first ten cells from XD battery on alibabba (Waiting for the other 10). I'm not home so have my wife do this stuff is a pain lol. Voltages are close but not great. I just wanted to make sure they have some juice in them before I touch or see them in 2-3 months. Pictures look ok. The terminals look new for the most part other than this one looks rough. Also had her pull the sticker off the top. Should it have another QR code underneath? They were about $40 a cell with shipping and ordering 20 of them. What do you guys think

 

[Dzl]

The second QR code underneath I believe is an indication that they are grey market cells (I don't believe this necessarily means they are good or bad cells), but it indicates that the seller may be obscuring the original manufacture or details of manufacture. There are a number of reasons for this from disengenuous to benign and contractual. It is one indication that they are less than A grade. If you found a QR code reader that could read both QR codes that would probably give you more info.

Take the above with a grain of salt, I'm basically just restating what I've heard/learned elsewhere, I don't have experience in this area.

 

[sremick]

If you found a QR code reader that could read both QR codes that would probably give you more info.

Reading the QR codes isn't the problem. It's what to do with the characters/numbers that result. Is there a lookup table/database anywhere that matches codes with manufacturers/models?