A123 20AH cells source?

[oatnet]

How many of them check 19.6Ah at even 1C? NONE?

1) If you are taking 20ah from your a 20ah cell, you are damaging it with a 100%DOD cycle. On a throwaway sample cell it would be an OK test to establish capacity, but it would be downright stupid to do with cells in your pack. I would get the IR from the sample cell, and compare the IR to the new cells. After a handful of 50% DOD cycles to wake up the battery, I might take it down to 80% and see if the curve matches what I got from a 100% DOD on the sample cell. But I definitely wouldn't damage my pack with irrelevant testing.

2) 19ah vs 20ah is not a relevant data point. Maybe the cells were rejected because they underfilled a run of cells - I suspect this is where the smaller 16ah cellman cells came from, as I haven't seen them listed as a product. Maybe their test regemin includes features like heating the cell to 100 degrees before discharge, yielding a few more WH. Maybe a123 overstates capacity on these cells, as most other batt manufacturers do.

The IR is a relevant data point, not to mention consistently having the same resting voltage after delivering same WH over 2 years of testing, as Toolman2 reports.

-JD

 

[Alan B]

If marketing says they're illegitimate cells, well we all believe marketing, don't we?

All those cells they made for GM weren't legitimate?

I agree that testing them for performance parameters is the best indicator. Even testing to near 100% DOD is not a problem if the cutoff voltage and current is properly chosen.

 

[frodus]

testing to near 100% DOD is not a problem if the cutoff voltage and current

and temperature

is properly chosen.

Not an issue usually at 1C, just wanted to throw it in there.....

 

[oatnet]

Even testing to near 100% DOD is not a problem if the cutoff voltage and current is properly chosen.

A 100% DOD explicitly defines the LVC for the test, it does not mean running a 20ah cell until you have pulled 20ah. Running to an LVC that corresponds to 80% DOD will give you the same curve, albeit attenuated, that one can use to compare cells.

I think mostly we differ here on definition of 'problem.' I would agree that a single 100% DOD is not likely to fail an a123 cell on the spot. However, a 100% DOD cycle will unnecessarily impact the cycle/calendar life of the cell, that is a problem for me, perhaps not for you. If it was a meaningful test, I might be OK with it. Of course, a123 is the best candidate for a 100%DOD test, a headway, ping, or cheap chinese 1C LiFe would be far more impacted.

-JD

 

[toolman2]

toolman2,
"we did this"..what do you mean?
where did you get your A123 20Ah cells from?
You say you are happy with them?
How many of them check 19.6Ah at even 1C? NONE?

"we did this" should be clear enough -as i quoted oatnet saying "Do they hold 19-20ah? What is their IR? The answer is simple: Buy a sample. If you like it and buy more, hope they are as good as the sample. This hobby is a crapshoot, there are no guarantees or warrantees"
so ive bought these cells from cellman, osn, and a123rc were handy for a single purchase free shipping so i bought one, it was good, bought 10 they were good, bought 50 they were good etc etc.

i stopped checking them after 3 orders of them, cos they ALL had 19.6 to 20.2ah capacity, around 1.2mohlms resistance, and could output 400a. -it just got boring..
the worst cell that arrived seemed like a dud with only 2v and had i bit of self discharge, but it had full capacity and its been in a pack working perfectly for 6 months now.

sorry if that is hard to deal with, but its just the facts.

 

[SlyCayer]

so i bought one, it was good, bought 10 they were good, bought 50 they were good etc etc.

Did the same thing with OSN, awesome cells, to be honest.

they ALL had 19.6 to 20.2ah capacity, around 1.2mohlms resistance, and could output 400a. -it just got boring..

Same thing for me on the results... Couldn't be happier with these awesome cells.

 

[miro13car]

no hard to deal with at all,
but
one would like to know what were QC criteria that A123 rejected those cells.

 

[Hillhater]

one would like to know what were QC criteria that A123 rejected those cells.

We dont know that they are " QC Rejects" ...just speculation.
They could equally be regular stock cells that have been "disposed" of as a result of stock rotation, or disposals of unused assets from terminated projects etc.

 

[oatnet]

one would like to know what were QC criteria that A123 rejected those cells.

Then one will be disappointed, since there is absolutely no way for one to know.

The cells we can get are supposed to be destroyed not resold, and a123 has no reason to share their QC critria with the people they pay to destroy rejected cells. Besides, I wouldn't believe the reseller's story if they said they knew it. Simple testing is the best indicator, and as you can see it has worked out for others.

-JD

 

[Alan B]

I have no compelling reason to believe that they were in fact QC rejected. Rejected product would not usually get final labelling applied. There are too many inconsistencies in this story.

What A123 marketing tells us is interesting, but not necessarily totally accurate. What they tell us is intertwined with their strange marketing policies.

Was all the product made for GM QC rejected?

Why did GM abort the contract? Did they suddenly find something wrong with the product?

Too bad, A123 is forcing the world to pass them by.

 

[miro13car]

AlanB
good point I forot about, thosecells have all those labels applied to them just like legal Mavizen cells?
but it would be interesting to compare Mavizen bought cell with A123RC cell, do they have all the same labels/with different numbers of course/.

 

[Hillhater]

Search some of the old A123 threads. There was some detail comparison of serial numbers/labels from different sources.
Depends what you are expecting to see ?
Remember also, it is known that A123 have adjusted the chemistry of those pouches over the years !

 

[Harold in CR]

Just a reminder, that, the cells I posted about said "Prototype Production" IN the specs. These are possibly where/how the USA cells are involved ??

 

[drunkencat129]

i think we should arange a swarm buy im intrested whats there c rateing just wondering

 

[edaz40]

look at the facts/the us goverment (the o man gave 100s of millions)to 123 to get them moving.then the state of michigan threw in free land,water and no property tax or state tax and a chance to hire thousands of sacked uaw union members, call them employees not so much,then the fed owned and directed gm to go all out on volt production,and will end up changing i.d. tags to whatever year we are in for a long time, and you will be buying left over 2011s for a long time.then gm drops 123 as a supplier,and the feds have their fingers in both co. at the same tine.how can there be a true winner.??? and to cap it off-the volts burn up on inpact,crash test,with dummies not your family thank god.,the o man again talks out of both his ass and mouth(can you tell the differance?) at the same time as he tries to pick winners and loosers .wishfull thinking \on the public buying anything from 123.thanks for looking.ed.

 

[jonescg]

edaz, you have just earned yourself a nomination for the most chaotic and out-there post on the forum :lol:

Dr Jones says, take two commas, a full stop and a semicolon before going to bed.

 

[LiFe]

edaz, you have just earned yourself a nomination for the most chaotic and out-there post on the forum :lol:

Dr Jones says, take two commas, a full stop and a semicolon before going to bed.

The caps, periods, and commas keys are two screens away on his smartfone running hemorrhoid -oof android, dang speel checker...

 

[oatnet]

Dr Jones says, take two commas, a full stop and a semicolon before going to bed.

:lol: :lol: :lol: :lol:

Even with punctuation, I don't think I could interpret that post.

 

[Hillhater]

This extract from an MIT Technology Review article may explain the A123 production facilities a little more ..
http://www.technologyreview.com/article/39311/

Chiang and his colleagues at A123 built a manufacturing plant in Changzhou, China . The move was meant not to outsource production, says Chiang, but to acquire the needed manufacturing know-how. Subsequently, A123 bought a South Korean manufacturer as a way to begin developing the expertise it needed to make the flat cells required for electric-car batteries. When A123 decided it needed to be closer to its potential automotive customers in Detroit, it cloned the Korean plant in Livonia, Michigan, and the Chinese factory a few miles away in Romulus, aided by a $249 million grant from the federal government. As a result of this strategy, A123 was able to become a major manufacturer in a remarkably short time, building the Livonia plant in just over a year and the Romulus plant in nine months.

The company soon became one of the nation's highest-profile energy startups—and one of the few that have scaled up their technology, building what it claimed in 2010 was the "largest lithium-ion automotive battery plant in North America." In 2009 it went public, raising around $400 million.

 

[The Mighty Volt]

18650s are the cheapest A123 B-grade cell now, at 2.05 USD a piece

Wait really? I thought all those ebay a123s were counterfeit.

Not necessarily, I made a 8s 1p string from some of them and was disharging them at 24v 15a, no problem.

Then I made 12s 1p string and discharged them at 36v 49A

 

[dnmun]

I have no compelling reason to believe that they were in fact QC rejected. Rejected product would not usually get final labelling applied. There are too many inconsistencies in this story.

What A123 marketing tells us is interesting, but not necessarily totally accurate. What they tell us is intertwined with their strange marketing policies.

Was all the product made for GM QC rejected?

Why did GM abort the contract? Did they suddenly find something wrong with the product?

Too bad, A123 is forcing the world to pass them by.

they were not rejected. that is the assumption these guys have been trying to justify for months.

they were the prototype run that A123 did for GM to prove they could meet GM's manufacturing requirements. ie, prove they were up and running.

but GM got a better deal, so all those cells that A123 manufactured in that prototype run were sold off to liquidation agents who now are selling it on taobao.

the comments about the only legitimate supplier being mavigen is easy enuff to jibe with this fact.

these cells are not being sold by A123, they are being sold by the liquidator. so the statement from A123 is correct, and these are legitimate A123 manufactured cells.

all jmho, but it seems obvious, how they got so far down that road i don't know. if someone had stamped a fake with the A123 logo then it woulda already have been siezed by A123's anti trademark infringement agents.

 

[jimw1960]

I just got an email from OSN Power saying they can now sell the full tab 20AH cells for $19 apiece. I'm sick of dealing with China and U.S. Customs but that sounds like a good deal if anyone is looking to buy 100 cells or more.

 

[SlyCayer]

If you guys are interested, you can buy 1 at a time from us, http://www.jccayer.com/product.php?productid=3246

 

[mistercrash]

Cibouère Jean-Claude! Kaziment $56 piasses pour une cell?!? Pi tu baisses même pas l'prix quand on veut en ach'té plusieur dans l'style de 100 peut-être comme tsé?!? Étu malada sti?! Pi après ça l'monde se d'mande poukoi qu'on achète pu Canadien clisse!

 

[Doctorbass]

Cibouère Jean-Claude! Kaziment $56 piasses pour une cell?!? Pi tu baisses même pas l'prix quand on veut en ach'té plusieur dans l'style de 100 peut-être comme tsé?!? Étu malada sti?! Pi après ça l'monde se d'mande poukoi qu'on achète pu Canadien clisse!

A ce prix la, je les voudrais avec contacts plaqué or ! :lol:

At that price, at least i would hope the contact tab to be gold plated! :lol:

No joke, one guy on ebay is selling a large batch of 72 units he call ''the perfect one'' at 28$ per cell and is 100% rating... but his seller rating never moved since one month... and have 13 auction history only

Doc