Group Buy? Dr.Bass Steveo found 7s3p Module! Awesome Price!!

[docnjoj]

Um........you guys feel that these are water cooled? I just ordered 14 individual cells from Victpower and will use agniusm's kit to assemble them. It really might pay to hold off until we see the assembly process and if they are welded. That could be a deal breaker, IMHO! Cutting apart spot welds is no fun, especially with those whimpy tabs!
otherDoc

[lukehutch]

I'm a n00b to e-converting motorbikes, but I don't want to miss out on the chance to capitalize on A123's misfortunes. Can somebody please answer a few ultra-basic questions about these?

-- What is the XsYp notation for batteries?
-- If I want to e-convert a Sachs MadAss (small, light scooter-like motorcycle) to have good pickup and a top speed of say 65 MPH while operating well at 35 MPH, roughly what size electric motor will I need (in terms of power output and voltage), and how many of these A123 cells will I need?
-- Can anybody guess how long these batteries will be available at low prices? Will this take the bottom out of the market for the foreseeable future, or should I rush to purchase batteries right now?

Thanks!

[deVries]

I'm a n00b to e-converting motorbikes, but I don't want to miss out on the chance to capitalize on A123's misfortunes. Can somebody please answer a few ultra-basic questions about these?

-- What is the XsYp notation for batteries?

X is the number of cells in S=Series P=Parallel. So, 7s3p is 7 cells x 3.6v per cell gets the voltage of the module in series 7s about 25v. And, 3p is 3 cells in parallel, so 3 x 20Ah/cell rating = 60Ah total capacity. ...the gas tank size so to speak.

-- If I want to e-convert a Sachs MadAss (small, light scooter-like motorcycle) to have good pickup and a top speed of say 65 MPH while operating well at 35 MPH, roughly what size electric motor will I need (in terms of power output and voltage), and how many of these A123 cells will I need?

Sorry, this is Off-Topic for this thread, and I don't know the answer. You'll need to post elsewhere about this.

-- Can anybody guess how long these batteries will be available at low prices? Will this take the bottom out of the market for the foreseeable future, or should I rush to purchase batteries right now?

Since these are being sold as surplus in small quantities, IMO, I think these will be available for a few months to maybe early next year, IMO. These modules will go faster if there are few defects & are easy to use or harvest the individual cells, so be alert about reports of testing these modules in the near future in May next month.

[agniusm]

If anyone gets their hands on these, I would really like to see how they are assembled inside, i.e. how are the cells held in place, how cooled, BMS close-ups, etc.

I would certainly want that info myself Main interest is about BMS on these packs. How one would go about connecting these modules S and P configuration, bulk charge them. Would be pretty good for automotive use, lighter and cheaper than CALB or TS +tons of current. 3P of these 1.2k amps on 60AH battery, not bad at all

[davec]

looking forward to seeing sutho's review
the loose cells from vict are trash
but cells coming in a pack in a legitimate a123 modules could be interesting....maybe their ripping them out of used sources but at least your getting a legitimate product...i dont think anyone will take the time and effort to assemble large modules with poor cells..unless these mods are dumps from that bad batch.. deveries hit the nail on the head... we need to waite out the review and see pics and voltages...

[MitchJi]

Hi,

If these packs are so great why is Mother Teresa's Battery Company selling them for so much less than the bare cells?

...It really might pay to hold off until we see the assembly process and if they are welded. That could be a deal breaker, IMHO! Cutting apart spot welds is no fun, especially with those whimpy tabs!
otherDoc

1st - There are 21 cells that could be stripped out & repackaged for about $13.50 each. That's $6 dollars cheaper per cell than just buying the bare cell.

If its that easy why isn't Vic Power hiring low priced Chinese workers to strip out the cells and selling them individually for $6 more per cell?

the cells Doctorbass got were ALL good & meet ALL factory specifications that are advertised.

http://www.a123systems.com/Collateral/Documents/English-US/LIV%20prismatic%20cell%20field%20campaign%20QA_FINAL.pdf

2. What is the cause?
One of four automated tab welding machines in the prismatic cell manufacturing process at our Livonia, Michigan facility was incorrectly calibrated, causing a misalignment of a certain component in some prismatic cells. This defect was undetected by our standard visual and electrical inspection. When the defective prismatic cells were subsequently compressed as part of the 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 breaches the foil pouch electrical insulation causing an electrical short which can cause premature failure of the battery module or pack, leading to decrease in performance and reduced battery life.

The good news is the flaw is too subtle for normal visual inspection to detect, and probably only causes problems in packs that are compressed on an assembly line. This means that individual cells carefully assembled into DIY packs should be fine.

OTOH the place where problems will occur is in these assembled packs.

So connecting the dots we have:
1. Packs that are so difficult to disassemble that its cheaper to sell them for ~30% less than raw cells, in a country with cheap labor.
2. Made with cells that are being dumped due to problems created when the cells are assembled into these packs.

Seems like a very good chance of getting bad packs (either bad initially or failing sooner than they should) that are very difficult to repair.

Also shipping is a big percent of the total cost and at least a little of the $6 per cell savings will be eaten by increased shipping so total prices might look like this:

$525 - 21 bare cells at $25 each (Canadian group buy price) including shipping
$409 - $283.3 + $126 (module price plus six dollars per cell shipping - about $1 per Cell more than the Canadian group buy costs)

So the total savings will be close to 20% rather than the ~33% cell price difference.

[agniusm]

My take on the whole matter is there is no such thing as grey market cells, rejects or graded cells. Mavizen sells supposedly grade A cells from A123 systems thou they state minimum cell capacity of 19.6? Why not 20AH if it is grade A cells. Most good cells i got from China were above that. The question stands if they will perform long term cause to me it looks like A123 dumps those cells to China to get rid of responsibility for their product, why? I might be hallucinating thou

[HumboldtRc]

Here is the email I got this morning.

"How are you ?

 We are so happy to hear from u

 About A123 Scalable Prismatic Module(7s3p)

It's 21V60AH

Quotation:283.3$

 Order quantity :2units

Goods weight :36-40KG

Shipping cost :298.4$( need wooden cases as packing ) by DHL (3-5working days arrive US)

Warranty:NEW AND undamaged and voltage test ok


We dont have detail documents specifications for these A123 modules

Coz these modules were produced by A123 original factory . no 1 processes them..

 Now In mainland of china,we no need use the modules,so bargain price to handle


Payment :T/T or Paypal




If u r still interested in these informations,pls contact with us in time

 We are gonna wait for ur reply

 Best Regards

It says "Warranty: New and undamaged and voltage test ok" , whatever that means...?

[deVries]

Quotation:283.3$

 Order quantity :2units

Goods weight :36-40KG

Shipping cost :298.4$( need wooden cases as packing ) by DHL (3-5working days arrive US)

Warranty:NEW AND undamaged and voltage test ok

Maybe there is a DOA guarantee, BUT there is a warranty according to your email shown directly above.

Where (what city) was the destination quote given for?

Thank you HumboldtRc for providing that information.

At least they think the defective units are *NOT* a safety issue... from A123 (thanks Mitch! ) ...

"As a result of engineering
analysis and testing, we believe the defect does not create a safety issue. A123 has not received or
discovered any reports of injury or property damage related to this situation. We maintain that our core
Nanophosphate® chemistry and our systems are safe, and this situation is ultimately a packaging issue
for which we have identified the root cause and have taken corrective action."

Btw, if that is the cost to ship to the USA, then the shipping price needs to come down somehow (by Sea or group buy or ?). Otherwise, this company will have to lower the price, imo, IMO.

So connecting the dots we have:
1. Packs that are so difficult to disassemble that its cheaper to sell them for ~30% less than raw cells, in a country with cheap labor.

That is only one *possible* reason among many other reasonable answers. We just do *not* know at this point. For example, 'why' do they state the following on the actual quote:

Warranty:NEW AND undamaged and voltage test ok

We need further clarifications AND LOWER shipping costs -or- lower pricing, IMO.

[DAND214]

SO WITH SHIPPING WERE LOOKING AT $20.60 A CELL, 42 cells!

Then we still don't know if they can be reconfiged.

Best we wait for some test results.

Dan

[HumboldtRc]

Quotation:283.3$

 Order quantity :2units

Goods weight :36-40KG

Shipping cost :298.4$( need wooden cases as packing ) by DHL (3-5working days arrive US)

Warranty:NEW AND undamaged and voltage test ok

Maybe there is a DOA guarantee, BUT there is a warranty according to your email shown directly above.

Where (what city) was the destination quote given for?


Thank you HumboldtRc for providing that information.

At least they think the defective units are *NOT* a safety issue... from A123 (thanks Mitch! ) ...

"As a result of engineering
analysis and testing, we believe the defect does not create a safety issue. A123 has not received or
discovered any reports of injury or property damage related to this situation. We maintain that our core
Nanophosphate® chemistry and our systems are safe, and this situation is ultimately a packaging issue
for which we have identified the root cause and have taken corrective action."

Btw, if that is the cost to ship to the USA, then the shipping price needs to come down somehow (by Sea or group buy or ?). Otherwise, this company will have to lower the price, imo, IMO.

So connecting the dots we have:
1. Packs that are so difficult to disassemble that its cheaper to sell them for ~30% less than raw cells, in a country with cheap labor.

That is only one *possible* reason among many other reasonable answers. We just do *not* know at this point. For example, 'why' do they state the following on the actual quote:

Warranty:NEW AND undamaged and voltage test ok

We need further clarifications AND LOWER shipping costs -or- lower pricing, IMO.

Northern California.

I'm going to buy 2. They garantee they will check the voltage and make sure the are fine, before shipping.

[deVries]

Well.....I bit the bullet and bought 22 x 7s3p units.

So.....providing the packs don't fail in a dramatic or dangerous fashion, I reckon these are good value. I also think there's a gonna be heaps available...

At least they think the defective units are *NOT* a safety issue... from A123 (thanks Mitch! ) ...

"As a result of engineering
analysis and testing, we believe the defect does not create a safety issue. A123 has not received or
discovered any reports of injury or property damage related to this situation. We maintain that our core
Nanophosphate® chemistry and our systems are safe, and this situation is ultimately a packaging issue
for which we have identified the root cause and have taken corrective action."

Sutho, at least you will not go up in flames according to A123 above!

PLEASE let us know your shipping cost, how shipped, etc. I think you are in OZ but at least it gives others an idea about shipping costs in 22 units.

Thanks again!

[deVries]

I'm going to buy 2. They garantee they will check the voltage and make sure the are fine, before shipping.

Thank you sir.

Do you intend to open-up the module & disassemble (if possible) at least to learn more about it, etc.

Please give us the actual weight & dimensions of the module after receiving, since no one has posted that yet.

Again, thanks!

[Sutho]

Prior to my purchase yesterday I had a lot of correspondence with Xin from Victpower. Although she seems a little reserved with the information, she also seems to be as helpful as she can be. I believe that they sometimes can't provide suitable answers on some questions because they honestly don't know. They come across as just another trading company with the right contacts to get products that others can't.

The terms of the purchase that we agreed on are that the modules must be New, Undamaged and showing Correct Voltage.

Xin would not agree to provide a refund on the modules if they were found to be DOA, faulty or bad (her term).....but she did agree to replace any bad modules with good modules providing I covered the freight component.....which is a damn costly portion.

They provided the following photo which is a new pack and shows no evidence of having been used. No marks on terminals, etc. I believe these are the potentially faulty modules that have not yet been assembled into the larger packs for Fisker and the like. A123 would be dumping them as it would be too risky for them to sell to the contract customers.

Xin said that I would receive 22 brand new modules exactly the same as these.

07s03p 60Ah End.jpg

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The following photo was sent to me by mistake.....but I believe it answers virtually all of the queries in this thread:

This will be obvious to most with any knowledge of the cells or modules, but what this shows to me is:

1. This module was forcibly removed from a larger Fisker pack....hence Fisker identifier label, bent tabs on end of module.

2. Victpower has the "real-deal" from A123.

3. Cell tabs are laser welded to busbars which results in shortened tabs. Thus cells that some have purchased with short tabs were not neutered on purpose, but more likely removed from modules.

4. Removing a group of faulty cells would not be an easy task....but would not be impossible either.

While the above photo initially looked bad to me, with the assurances from Xin, it was the one that pushed me over the line to proceed.

I have been thinking for some time that if I could only get my hands on one A123 module, I would copy it for my own packs as all the engineering is done and the cells are supported and connected as they were designed to be.

Although it is very likely that I will end up with some of the faulty cells in these modules, I believe that repairing them will be much easier than building modules from scratch.

I should receive the modules by the end of next week and provide feedback on their condition, voltages, etc. I will also like to build some form of test rig, so if anyone has suggestions on what this should be, I am all ears.

Cheers,
Sutho

[deVries]

4. Removing a group of faulty cells would not be an easy task....but would not be impossible either.

With a vacuum & dremel blade it looks like you could cut the bus bar between the tabs to remove a bad cell. You would have to cut the two outside bands for the battery pack to remove the bad cell, but, dang, that seems easy-peasy on the face of it. Always easier said than done.

Also, since this is a pressure issue compressing the cells together, causing the defect, heck, it might be possible just to relieve the pack pressure by loosening the bands relieving compression. That might make the "potential" bad cells become good cells like MAGIC.

How much was shipping?

Thank you! Sutho.

[Sutho]

How much was shipping?

Shipping to my location for 22 units was $2500.

[deVries]

...but she did agree to replace any bad modules with good modules providing I covered the freight component...

Considering these are surplus with the certainty there will be some defective cells *UNLESS* my theory of "decompressing" the cell-stack will prevent the defect from ever happening... & it's possible that idea could work & prevent any defects...

Here is why I think this is possible directly from A123:

"When the defective prismatic cells were subsequently compressed as part of the 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 breaches the foil pouch electrical insulation causing an electrical short which can cause premature failure of the battery module or pack, leading to decrease in performance and reduced battery life."

So, decompressing this interface, the cell stack, may *prevent* the defect from ever becoming actually defective in use... just a little less pressure and the potentially "bad" cell survives as a "good" cell. Magic!

Anyway, I think replacing a bad module for free IS much better than no warranty at all. I think you have snagged an awesome deal, *IMO*.

Fantastic!

[deVries]

no weight or dimension info yet?

Just need dimensional information, I won't order them if I can't put to use the modules in my motorcycle.

If you examine the pics posted just above in this thread, then you can see the battery or module size is very near the size of the cells x number of cells stacked in "X" configuration. You might be able to estimate if these will work by using the cell dimensions & making an estimate from that. Obviously, if that estimate is too close to tell, then you'll need to get the exact dimensions. Several have ordered the 7s3p modules, so we will know within a week or so the exact weight & dimensions for that module.

Hope you can get these to fit & work.

[competitions]

There is also a guy in Ireland who uses the online name of "Jack Bauer"- and he has built an EV.

Coincidence? Possibly.

His build thread:
http://www.diyelectriccar.com/forums/sh ... jack+bauer

[deVries]

I should receive the modules by the end of next week and provide feedback on their condition, voltages, etc. I will also like to build some form of test rig, so if anyone has suggestions on what this should be, I am all ears.

Doctorbass, Sir Battman! The Nano Battery Appears in the Night Sky...

Can you help give Sutho some ideas for this?

[Doctorbass]

I should receive the modules by the end of next week and provide feedback on their condition, voltages, etc. I will also like to build some form of test rig, so if anyone has suggestions on what this should be, I am all ears.

Doctorbass, Sir Battman! The Nano Battery Appears in the Night Sky...

Can you help give Sutho some ideas for this?

Sutho ,

This is my suggestion for the test of your cells:

1- Visual inspections on arrival ( physical damage te strange things)
2- If possible put a number on each cell for easy data record.
3- measure voltage of all cells
4- record all voltages of all cells
5- charge all cells to 3.650V at C/2 at normal ambiant temp and cut charging process when current drop to C/20
6- leave the cells sitting for 48 hours
7- measure voltage of all cells ( keep appart the lower cells that have droped by 50mV for severe test or droped by 100mV for economy test
8- record voltage of all cells
9- discharge all cells or cells group (if they are already connected) at 0.5C or 1C and cut the discahrge to 2.0V ( some will say 2.5v)
10- record all measured capacity
11- measure voltage of all cells
12- leave the cells sitting for 48 hours
13- measure voltage of all cells ( keep appart the lower cells that have droped their voltage lower than the average)
14- charge again all cells to 3.650V at C/2 at normal ambiant temp and cut charging process when current drop to C/20
15- leave the cells sitting for 12 hours
16- discharge all cells or cells group (if they are already connected) at 5C or 10C and cut the discharge to 2.0V
17- record all measured capacity
18- compare for all cells their capacity at 0.5 or 1C with the 5 or 10C capacity
19- cells that have have higher diff of capacity between the low and high C rate discharge have a higher internal resistance and should be kept appart.
20- All cells sorted !

Doc



-

[agniusm]

He, he, that looks some job:) I dont think it would be handy to record cell ID's unless u take all apart? Hows the liquid cooling is achieved on these modules? Is it those holes used on the side?

[deVries]

Sutho ,

This is my suggestion for the test of your cells:

1- Visual inspections on arrival ( physical damage te strange things)
2- If possible put a number on each cell for easy data record.
3- measure voltage of all cells
4- record all voltages of all cells
5- charge all cells to 3.650V at C/2 at normal ambiant temp and cut charging process when current drop to C/20
6- leave the cells sitting for 48 hours
7- measure voltage of all cells ( keep appart the lower cells that have droped by 50mV for severe test or droped by 100mV for economy test
8- record voltage of all cells
9- discharge all cells or cells group (if they are already connected) at 0.5C or 1C and cut the discahrge to 2.0V ( some will say 2.5v)
10- record all measured capacity
11- measure voltage of all cells
12- leave the cells sitting for 48 hours
13- measure voltage of all cells ( keep appart the lower cells that have droped their voltage lower than the average)
14- charge again all cells to 3.650V at C/2 at normal ambiant temp and cut charging process when current drop to C/20
15- leave the cells sitting for 12 hours
16- discharge all cells or cells group (if they are already connected) at 5C or 10C and cut the discharge to 2.0V
17- record all measured capacity
18- compare for all cells their capacity at 0.5 or 1C with the 5 or 10C capacity
19- cells that have have higher diff of capacity between the low and high C rate discharge have a higher internal resistance and should be kept appart.
20- All cells sorted !

Doc

Thanks! Doc

What is your opinion of the NASA Bounce-Back test too?

[Sutho]

Hey Doc,

Thanks for the procedure. Will probably initially do that for each module.....as opposed to cell....and will make comparisons between all units and record results.

Cheers,
Sutho

[Sutho]

Hows the liquid cooling is achieved on these modules? Is it those holes used on the side?

The units do not have liquid cooling themselves. They are designed to be mounted on a cold plate which has some form of cooling. The metal plates between each cell or cell-group are heatsinks which lap around the bottom of the cells. The bottom part of these heatsinks are the part that make contact with the cold plate.

There is quite a bit of info about the design and construction of these units available in the web. The following is a quick animated view of how they hang together:

http://www.youtube.com/watch?v=axLnLcH_mmM

There's also this rather large document that's worth a flick through:

A123 Weight and Size Reduction of a Lithium-Ion Battery Pack for an Extended Range Electric.pdf

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