# A123 modules for sale: too good to be true?



## The_Sasquatch (Feb 11, 2018)

Attached are some photos of some A123 modules that are for sale... the price is good (<140$ / kWh) but the seller can't provide any documentation proving the claim that these are new 11/2017 production or that they aren't factory rejects of some kind... 

Does anyone recognize these modules, or know how to decode the label to determine a manufacturing date?


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## DrJeff (Apr 24, 2015)

For comparison with your data, this is a pic of a A123 module out of a 2014 Chevy Spark EV...


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## john61ct (Feb 25, 2017)

Wow!

It is true, is it not, that **any** A123 pack will be LFP?


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## brian_ (Feb 7, 2017)

john61ct said:


> It is true, is it not, that **any** A123 pack will be LFP?


Not quite: while the original A123 Systems of the cylindrical cell era may have produced only LFP cells (in 18650, 26650 and pouch formats), the company died in 2012 and was revived, with the current product line including both LFP and NMC pouch cells (and apparently no cylindricals).
A123 Systems - Cells

On the other hand, the cells provided to GM for the Spark (until 2104) were LFP, and any pre-2013 A123 cells are presumably LFP as well.

The 2014 Spark EV modules shown are 28S 3P, with ~20 Ah 3.3 V (nom) LFP cells. If the mystery modules are composed of the same cells, they would be a 26S 3P configuration. I have only seen one spec for the Spark EV with A123 modules, so presumably these are from (or for) something else.

Since there is no current A123 LFP cell at about 20 Ah (or 58.8 Ah) intended for EV use, it seems unlikely that a 2017 module like this would be built with them... but perhaps they were the last of a product which was recently discontinued. If they are NMC, they would need to be a 23S configuration, but I don't see how any of the currently produced NMC cells could be combined for 58.8 Ah capacity.

No one seems to like to show the bottom of a module. If these are EV modules, they likely have a metallic bottom face for contact with a thermal management plate, which is the system used in the Spark EV and other similar modules without internal plumbing for heat transfer liquid.


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## brian_ (Feb 7, 2017)

These modules are presumably of the design described in this video:
GoElectricDrive.com: A123 video presenting prismatic battery pack

A123 Systems' modules are still constructed this way, but apparently not with these cells.


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## brian_ (Feb 7, 2017)

The_Sasquatch said:


> Does anyone ... know how to decode the label to determine a manufacturing date?


Have you considered asking A123 Systems?


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## brian_ (Feb 7, 2017)

And one more question: do you have dimensions (length, width, height) for these modules? Just curious to see if they match anything known, or are compatible with the dimensions of known cells.


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## john61ct (Feb 25, 2017)

I found an eBay seller but much higher price and listed as out of stock.

Being pouches, I guess not easy to reconfigure as nominal 48V (16S).

That's what I'm really trying to get to, strictly LFP only.

20-25Ah would be a decent pack increment to work with,

but if needed to be higher, up to 200Ah would be OK. 

1S, 4S or 8S increments good as well.


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## The_Sasquatch (Feb 11, 2018)

brian_ said:


> Have you considered asking A123 Systems?


I have reached out, but I am not confident I will get a response.


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## The_Sasquatch (Feb 11, 2018)

brian_ said:


> And one more question: do you have dimensions (length, width, height) for these modules? Just curious to see if they match anything known, or are compatible with the dimensions of known cells.


I should have attached the datasheet to the original post. This is what the seller provided.


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## john61ct (Feb 25, 2017)

want!

Before ordering, get set up to do a constant-current load test:

Charge to 91V at say 5-10A, maybe hold until trailing amps drop to say 2A, if you're feeling generous.

Start a timer, draw down at say 5.9A constant

How long (X.xx hours) precisely to get to LV cutoff at 77.9V ?

Start recharging immediately, up to say 80-85V for storage.

X's proportion to 10 hours is your % State of Health / residual capacity.

If you want to be hard-nosed, anything under 95%, send 'em back, not NOS as claimed, or otherwise compromised.

And if buying multiples, all should be the same result within 1-2% anyway.


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## john61ct (Feb 25, 2017)

oops

more characters needed


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## The_Sasquatch (Feb 11, 2018)

john61ct said:


> want!
> 
> Before ordering, get set up to do a constant-current load test:
> 
> ...



Thanks for the advice! 

The seller has agreed to extend a return policy that if I am dissatisfied in any way, I can return them.

However, I don't have a testing setup built yet. The donor vehicle I am using has a pair of functional 18kw EDN chargers, but these are 360v output and I don't have configuration software for them yet.. do you have a recommendation for a charger that is configurable for the test you propose? should I be searching for an inexpensive EV charger, or a big variable power supply? 

For the discharge, I am in the same situation, I don't have a lot of equipment yet. My first thought is a small electric motor & controller throttled based on a ammeter output, but I don't have a 90vdc motor... is there a better solution?


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## brian_ (Feb 7, 2017)

The_Sasquatch said:


> For the discharge, I am in the same situation, I don't have a lot of equipment yet. My first thought is a small electric motor & controller throttled based on a ammeter output, but I don't have a 90vdc motor... is there a better solution?


A motor isn't a useful place to dump energy unless it is driving a load. If you're just throwing the energy away, you want a big resistor (plus of course a controller).


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## brian_ (Feb 7, 2017)

The_Sasquatch said:


> I should have attached the datasheet to the original post. This is what the seller provided.


I suppose that could be composed of the still-current 20 Ah NanoPhosphate cells, although the package dimensions are pretty tight for the 161 mm x 227 mm cell size. The module isn't current, and they don't promote that cell for EVs any more (the current version of the 20 Ah LFP cell is "optimized to balance the power and energy requirements of 12V starter batteries"), but as I suggested earlier it might be a very late example of a recently discontinued module offering. The date on the datasheet is 2013, but it could have been in production for four years.


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## The_Sasquatch (Feb 11, 2018)

brian_ said:


> The_Sasquatch said:
> 
> 
> > For the discharge, I am in the same situation, I don't have a lot of equipment yet. My first thought is a small electric motor & controller throttled based on a ammeter output, but I don't have a 90vdc motor... is there a better solution?
> ...


I didn't stop to consider that a motor controller could just as easily drive a power resistor. Sounds like a good DC ebike controller and some power resistors is the way to go for discharging.


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## brian_ (Feb 7, 2017)

john61ct said:


> Being pouches, I guess not easy to reconfigure as nominal 48V (16S).
> 
> That's what I'm really trying to get to, strictly LFP only.
> 
> ...


The datasheet lists "laser welded internal connections", suggesting that you might be guessing correctly about reconfiguration within a module.

What you want is actually a good match to what A123 Systems has made. Currently, though, their LFP 48 V modules are only 6 Ah and 8 Ah (for mild hybrids), and their modules of the style we're discussing are only NMC (although they come in 12S 1P and 4S 3P with 37 Ah cells).


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## john61ct (Feb 25, 2017)

brian_ said:


> Currently, though, their LFP 48 V modules are only 6 Ah and 8 Ah (for mild hybrids)


Which means 24-32Ah equivalent to 12V, which would be OK.

Never see these come up retail direct to, users though.

> their modules of the style we're discussing are only NMC

Huh? all the modules discussed in this thread so far are LFP afaict.

I have no interest in any other non-lead chemistry personally.


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## brian_ (Feb 7, 2017)

john61ct said:


> > their modules of the style we're discussing are only NMC
> 
> 
> Huh? all the modules discussed in this thread so far are LFP afaict.


All of the modules which are built in the style shown in this thread and which are *currently* offered by A123 Systems are only NMC, as shown on their website. The LFP modules which are the subject of this thread appear to be discontinued products, as are of course the 2014 Spark EV modules (replaced by LG modules like those of the Volt for 2015).


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## The_Sasquatch (Feb 11, 2018)

john61ct said:


> want!
> 
> Before ordering, get set up to do a constant-current load test:
> 
> Charge to 91V at say 5-10A, maybe hold until trailing amps drop to say 2A, if you're feeling generous.


How important to the results of this test is the starting charging current? Would I be better off buying an programmable EV charger like the thunderstruck(https://www.thunderstruck-ev.com/tsm2500-and-charge-controller.html) or would a variable supply like this work? https://www.ebay.com/itm/Sorensen-D...292589?hash=item4691d3e06d:g:7cQAAOSwgBVciDFE


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## john61ct (Feb 25, 2017)

The_Sasquatch said:


> How important to the results of this test is the starting charging current? Would I be better off buying an programmable EV charger like the thunderstruck(https://www.thunderstruck-ev.com/tsm2500-and-charge-controller.html) or would a variable supply like this work? https://www.ebay.com/itm/Sorensen-D...292589?hash=item4691d3e06d:g:7cQAAOSwgBVciDFE


It is absolutely critical to get apple-to-apple comparison results tracking SoC over time,

that you have a **standardized repeatable** end-charge SoC (or use precise resting voltage) as well as end-discharge LVD.

A straight power supply will do, long as you and your ammeter are regulating things precisely.

Relying on opaque automated gear is great, but when it breaks you need to match its results for that purpose.

NBD for a once-off go/no-go test, long as you keep your parameters standardized / repeatable for comparing between units.


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## john61ct (Feb 25, 2017)

brian_ said:


> All of the modules which are built in the style shown in this thread and which are *currently* offered by A123 Systems are only NMC, as shown on their website. The LFP modules which are the subject of this thread appear to be discontinued products, as are of course the 2014 Spark EV modules (replaced by LG modules like those of the Volt for 2015).


Yes, and here so far afaict, we're only discussing the LFP ones.

The newer (post 2014) version being NMC, would have a drastically shorter lifespan, very different care protocols, and be much riskier wrt thermal runaway.

Thus if discussed, should be in a separate thread.


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## kunkler999 (Nov 29, 2018)

Mind sharing where you're buying these from? I am looking for some batteries for my EV. Thanks!


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## The_Sasquatch (Feb 11, 2018)

kunkler999 said:


> Mind sharing where you're buying these from? I am looking for some batteries for my EV. Thanks!


I've asked the seller if he minds me passing along his Contact information. The seller has satisfied me that the modules are legit new production ( produced an A123 shipping manifest showing the modules were initally manufactured and bound for Solaris bus and coach in Poland in the timeframe he claims they were produced)

For your information, I'm paying 6000$ for a pallet of 8 modules, just over 40kWh, or 147$/kWh.


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## brian_ (Feb 7, 2017)

The_Sasquatch said:


> ... the modules were initally manufactured and bound for Solaris bus and coach in Poland...


That makes sense. Lots of good deals in EV components come from failed business attempts... like the Azure Dynamics collapse. The Solaris site is too vague in technical specs to reasonably guess at what changed; they still build electric buses, so they may have changed battery suppliers or cell chemistry, or just over-ordered and cancelled.


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## john61ct (Feb 25, 2017)

What practical recourse do you have if they fail your tests on arrival?


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## john61ct (Feb 25, 2017)

The_Sasquatch said:


> I'm paying 6000$ for a pallet of 8 modules, just over 40kWh, or 147$/kWh.


Including delivery?


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## The_Sasquatch (Feb 11, 2018)

john61ct said:


> The_Sasquatch said:
> 
> 
> > I'm paying 6000$ for a pallet of 8 modules, just over 40kWh, or 147$/kWh.
> ...


No, I'm working up a delivery cost separately... I should have also noted that the modules also have a123 designed module level battery management boards that can communicate with a central controller via CAN.


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## DrJeff (Apr 24, 2015)

The_Sasquatch said:


> No, I'm working up a delivery cost separately... I should have also noted that the modules also have a123 designed module level battery management boards that can communicate with a central controller via CAN.


If you get the CAN protocol information I would be very interested. I figured out 80% of the CAN coming from the battery pack in the Spark EV (which hosts 4 similar A123 modules). I haven't tried to read or access CAN directly from the module/BMS units themselves.


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## The_Sasquatch (Feb 11, 2018)

DrJeff said:


> If you get the CAN protocol information I would be very interested. I figured out 80% of the CAN coming from the battery pack in the Spark EV (which hosts 4 similar A123 modules). I haven't tried to read or access CAN directly from the module/BMS units themselves.


The CAN bus ICD exists PM me your email.


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## highcurrentcustoms (Oct 29, 2019)

https://www.ebay.com/itm/153713692059

they are on Ebay they have 30 modules for sale..


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## john61ct (Feb 25, 2017)

be aware local pickup means no eBay/PayPal guarantee


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## highcurrentcustoms (Oct 29, 2019)

I have done a lot of pick up only transactions on eBay and have had my pay pal account has been refunded every time there was an issue with the item during pickup.


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## john61ct (Feb 25, 2017)

Was that since they split into separate companies?

If so, claiming through PayPal or eBay?


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## MikeAndreae (Apr 21, 2020)

In case you need more batteries I bought 2 cells from a 2014 Chevy Spark off someone in Quebec, they were from a crash test car (only 50km of use!) They're in great shape. If someone is looking I can see if he's still got some, I know he has a variety of old scrapped batteries. I think they were $1000 each.

If you're going to be in Ontario/Quebec he can deliver if you wait a few months (he comes down for shopping etc... periodically).

I'm still trying to fully decode the can signals on them, I seem to be getting max/min and average cell voltage off each side (14s) but I cant tell if they're balancing or not.


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## Isaac97 (Jun 3, 2019)

MikeAndreae said:


> I'm still trying to fully decode the can signals on them, I seem to be getting max/min and average cell voltage off each side (14s) but I cant tell if they're balancing or not.


If you contact Thunderstruck Motors they might be able to help you with the CAN signals. They have a lot of those modules and I believe they were working on the BMS system.
-Isaac


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## kunkler999 (Nov 29, 2018)

MikeAndreae said:


> In case you need more batteries I bought 2 cells from a 2014 Chevy Spark off someone in Quebec, they were from a crash test car (only 50km of use!) They're in great shape. If someone is looking I can see if he's still got some, I know he has a variety of old scrapped batteries. I think they were $1000 each.
> 
> If you're going to be in Ontario/Quebec he can deliver if you wait a few months (he comes down for shopping etc... periodically).
> 
> I'm still trying to fully decode the can signals on them, I seem to be getting max/min and average cell voltage off each side (14s) but I cant tell if they're balancing or not.


I am in need of a few Spark (28s3p) battery's. Can you see if he still has a few and if he'd ship to the USA (Ohio to be exact). Thanks! 

Question while I have your attention, can the 26s3p A123 be used along side of the Spark A123 (28s3p) pack? In parallel or series? Its almost impossible to find 2014 spark batteries and when you do people want huge sums of money. I would rather sell my spark battery and buy the 26s3p because it would be cheaper.


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## sime (Nov 15, 2019)

I have 12 of the 28s3p 60AH modules if anyone is interested along with Master BMS units Vehicle has less then 4300 miles on it as i currently still possess it. I'm in NY, 10958. I myself have been trying to figure out how to just read the MBB as I am using just one module for a few projects.


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## kunkler999 (Nov 29, 2018)

sime said:


> I have 12 of the 28s3p 60AH modules if anyone is interested along with Master BMS units Vehicle has less then 4300 miles on it as i currently still possess it. I'm in NY, 10958. I myself have been trying to figure out how to just read the MBB as I am using just one module for a few projects.


How much do you want for them? I'm in Ohio 43229


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## sime (Nov 15, 2019)

Check your PM.


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