Beware American A123 prismatic cells!

neptronix

Administrator
Staff member
Joined
Jun 15, 2010
Messages
18,011
Location
Utah, USA
Thought this was worth sharing - reading some of the pdf's on the links gave more info on root issue.

This defect was undetected by our standard visual and electrical inspection yielding cells which initially met specification. When the prismatic cells with the undetected defect were subsequently compressed as part of the standard module assembly process, a mechanical interference was created between the misplaced component and the foil pouch which contains the cell. In certain cases, this interference can breach the foil pouch electrical insulation, causing an electrical short which can cause premature failure of the battery module or pack, including a decrease in performance and reduced battery life.
We have isolated the root cause of the defective cells to this single automated welding machine, and have recalibrated it to conform with the other three automated welding machines at the Livonia facility. Cells made using these other three machines are not defective, giving us confidence that we have pinpointed the source of the defect and corrected it.
 
Good find ohzee. I should have read further..
 
25% of Livonia production material was affected.
One of four stations that prealign and weld the tabs was misaligned by approximately 2mm, resulting in possible pouch fusing, or pouch separation (seal) problems.
Lot identifiers don't resolve to individual stations, so 100% is suspect.
 
Saw this in the paper this morning. A123 is likely a goner. Now they can file bankruptcy leaving the stockholders with nothing, while they sell the little IP they have. Will be interesting to see who the new buyers are.

Funny how when the moved production line to the USA they were sabotaged. Not funny actually, sad really. Look how one country has cornered the solar/windmill/rare-earth marget. Price/run/buy your competitors out of business and then charge whatever you want in 5-10 year. We need more long term thinkers. I would recommend you guys check out http://longnow.org/

Research what happened to Evergreeen solar and their radical ribbon technology, and you will know what will happen to A123.
http://www.xconomy.com/boston/2011/01/11/evergreen-solar-to-shut-down-massachusetts-plant-lay-off-800-workers/
http://www.renewableenergyworld.com/rea/news/article/2011/11/evergreen-solar-finds-chinese-buyer-for-its-technology


--------------
French electrical engineering and power management company Schneider Electric SA (SU.FR) has relocated top executives to Hong Kong, including CHIEF EXECUTIVE Jean-Pascal Tricoire, who will share his time between Paris and Asia, in a bid to boost activity there.

A123 CEO worked for Schneider Electric and has been selling his A123 shares as fast as he can

Chinese president visits Schneider Electric in Nice
 
Well that sucks, sounds like those bargain A123 cells aren't so good :(

Darn. Would have gone great in the vectrix...
 
Even if these cells have a shelf life of one year I would call them a good deal, can't beat the cost per watt hour!


I'm willing to risk it.
 
If a123 is telling the truth, "only" 1 in 4 cells might be bad out of all the reject packs (1 of the 4 machines was not calibrated right). What you might want to try is fully charging the cells, clamping in a vice with moderate force, and then let sit for a few days. Those with internals shorts would exhibit higher self discharge I would think.
 
That suck's.

But im willing to risk it even if it lasts 1 or 2 years.
Hopefully defective cells dont go boom in the ebikes, But they have been around long enough now and i have not heard of any radical explosions from the a123 pouch cells.
I stabbed one with a shovel b4, made smoke in my entire back yard. More smoke than stabbing a 5s 5ah turnigy pack cells in one go.
The most scary cells for my are my little 18650 cells, they are like grenades when you put them under thermal stress they go bang, looks like bullet shells after they explode
 
Well, so they die when they are clamped together. So lets not clamp them together hard when we build bike packs :)
 
Hmm, I hope price droop on A123 prismatic packs in china is just a coincidence. :roll:

even if it is no coincidence, it is still open which is the cause and which is the effect ...
 
slippman said:
Well, so they die when they are clamped together. So lets not clamp them together hard when we build bike packs :)

The clamping process is part of the assembly line, perhaps they make the resistance less in the battery so that the battery life goes down by half.
 
nechaus said:
That suck's.

Hopefully defective cells dont go boom in the ebikes, But they have been around long enough now and i have not heard of any radical explosions from the a123 pouch cells.

dont want to be an alarmist but this article i read today in wsj is pretty freaky concerning a123 extreme tests. altohugh it did state it was an experimental battery.

"The experimental battery involved in Wednesday's incident was being developed for all-electric cars, including a coming line of Spark subcompacts,"

http://online.wsj.com/article/SB10001424052702304444604577337704120872184.html
 
LiFe said:
Lot identifiers don't resolve to individual stations, so 100% is suspect.

If that is correct, and they do not have production traceability back to individual welders, with / date/day,/ time identification ....then they are F**kin idiots and deserve to loose all their customers. ! :shock: :shock:
With a product value of this level and customer expectations for these packs, to not employ simple proven process tracking is a huge screw up !
GM, Fisker etc are also equally dumb not to insist on 100% traceability which is a common purchasing contract inclusion.
Its not even clear if you can differentiate between USA made cells and Asian made products ( USA marking on both !)

How do such rank armatures get to run these key industries ?
 
Back
Top