A123 from China. C and avoid [SOLVED]

[circuit]

Have you had a chance to measure internal resistance of died cells? It is interesting how A123 pouch dies.

I'm the one "with lab equipment and a bit of knowledge", who tested these cells.
The "USA" cells are good (internal resistance not tested), measures at ~19.9Ah.
The Korean cells are "dead". Will not take any charge, current simply does not go over 0.00 amps. Test done at 3.65V and over. Even reverse connection gives no current. So, there is no way to test a capacity nor internal resistance.
But, for the funny part, these dead cells measures as a bipolar 900nF capacitor All of them, with dissipation factor 0.0004, so internal resistivity is in 10-megaohm range. To explain this, the lithium part of the cell is completely dead and cell performs like a simple film capacitor with value of 900nF.

[agniusm]

Pagaliau, uzkniso kai kurie asilai Dekui

[LiFe]

agniusm, Thank You for taking the time to warn others about this supplier, and the surplussed prismatic A123 HD20 cells. Buying from unknown Chinese vendors can certainly be a dodgy affair at best. It wasn't a waste of your time detailing it for us.
Hopefully you'll be successful in your paypal claim.

There are "members" here who enjoy trolling (myself included), so please ignore these tossers and move on to answer the questions that appear sincere.

[Jason27]

Looks completely counterfeit. Nice to know people on here support ripping off the American company a123. Shame on you. You get what you pay for.

[agniusm]

Looks completely counterfeit. Nice to know people on here support ripping off the American company a123. Shame on you. You get what you pay for.

They ripping of them selves by not setting up proper distribution for the likes of me nor in US nor in Europe! I sure dont support companies like this one, me and others a like here support cleaner transportation maybe cleaner future for our children. You are completely missing the point. Looks like Bush supporter

[bigmoose]

agniusm, first thanks for this thread. The Korean cells are sure an interesting data point. No activation at all and behave as a simple capacitor. Sure would like to cut them open and see if they forgot a layer or two in manufacturing!

Could you do me a favor on the tabs of your cells?

Confirm that they are 4.5cm wide by 2.6cm long?
Can you measure the thickness of each?
Can you tell the material of each tab?

Sincere thanks!

[agniusm]

Will get that checked for you. The tab material i am not sure but it seems they are different, at least looks different. One by the looks is aluminium. Will check the sizes later

The sizes:
45mm width
27mm length

[slawek]

Hi guys,
There is a lot rumor going on about A123, and I just thought this might be useful information where to buy these cells.
I just got my package of 14 pieces A123 for my future project. I purchase form http://www.a123rc.com. All cells I got are made in USA. Voltage is in range 3,25V - 3,33V. I pick them for $39,99 a piece + free shipping. Tabs are 25mm long.
After all I think it was good deal.

*************************************
This is a little out of topic, but if someone is planning build battery pack for RC drive using cells 26650 LiMnNi 4Ah from http://www.batteryspace.com
Just don't waste your time and money. (If you are interested about battery pack i build 7S10P http://endless-sphere.com/forums/viewtopic.php?f=28&t=26699 )
After my comments on their web site for some reason my post was deleted, and now I assume the same battery have green thermal shrink (use to be orange)
And constant discharge current is 4A (use to be 10A).

[miro13car]

Slawek,
did you read thread by electricdirtbikerider in this subforum just 5-7 topics down of this thread?
He also bought from A123RC, his cells are not stright, bent but voltage OK.
Plase, tell us about cells appearance -are cells bent?
plastic trays clean? tabs on cells pristine, any dents or scratches on them?

[slawek]

Hi miro13car,
I read that thread by electricdirtbikerider, sounds close to mine experience .
I put ruler on each of them and seems to be slightly bent, maybe a 1mm on their lenght. I think this is do to shipping and a little flexible trays, but i put them on desk and press them with force about 5lb and they got perfectly straight. Tabs except one appear to be in perfect condition.
There is no dents, only really small marks here and there, but I am not concern about that, because after put them in case I will not see them anymore
Plastic trays are a little dusty, probably recycled or were long time in storage.
I will check capacity, and post the results, but this will take a time.

[agniusm]

Some update. Got response from Chinese guy. He was asking me to cancel paypal claim and he would post replacement cells right away. I think that was last attempt to trick me. I told him that i will cancel paypal claim when i get the cells and test them. After a while he responded that the cells are being prepared for shipment so i am really interested in how it will end. At the moment paypal is reviewing the claim so Chinese guy has until December 29.

[999zip999]

Good luck that a lot of time and money let is know how this works out.

[slawek]

Hi guys
It took me a little bit of time, but here comes a result from capacity tests.
First, test conditions:
Temp cells in range 75°F - 79°F (24°C – 26°C) Sensor attached to the side of the cell.
Full charged cut off set at 3,6V
Discharge cut off set at 2,5V
Charge/Discharge 0,5C (10A) – These is max capability of my equipment.
According to brochure form A123 system http://www.a123systems.com/Collateral/Documents/English-US/A123%20Systems%20AMP20%20Data%20Sheet.pdf
I should expect minimum capacity at 19,6Ah (I do not wont to even think about 20Ah that a123rc says)

Unfortunately results are a little bit of disappointing.
Only 2 of them have expected these capacities

Cell 1 – 18,726 Ah (-0,874 Ah)
Cell 2 – 19,004 Ah (-0,596 Ah)
Cell 3 –18,949 Ah (-0,651 Ah)
Cell 4 – 18,992 Ah (-0,608 Ah)
Cell 5 – 19,517 Ah (-0,083 Ah)
Cell 6 – 19,842 Ah (+0,242 Ah)
Cell 7 – 19,576 Ah (-0,024 Ah)
Cell 8 –19,815 Ah (+0,215 Ah)
Cell 9 – 19,442 Ah (-0,158 Ah)
Cell 10 – 19,378 Ah (-0,222Ah)
Cell 11 – 19,307 Ah (-0,293 Ah)
Cell 12 – 19,266 Ah (-0,334 Ah)
Cell 13 – 19,372 Ah (-0,228 Ah)
Cell 14 – 19,159 Ah (-0,441 Ah)

Now I am thinking of opening dispute trough PayPall, but I am not sure if there is the point, because I could not find any official information on http://www.a123systems.com about HVC/LVC, and maybe factory test them differently. So far looks like I was screwed on over 4Ah in total.
This really pised me off, because I feel to be screwed second time.
First by http://www.batteryspace.com on 4Ah LiMnNi - 26650 Cell that died after 140 cycles, and now by http://www.a123rc.com

I need guys your advice. Is it worth opening dispute? Is it possible to get these battery with capacity that data sheet says? Or they are what they are? Can anyone more experienced explain me, what is wrong or maybe not with these capacities?

[dnmun]

what equipment? how did you calibrate it? why did you only charge to 3.6 and shut off at 2.5 when everyone else uses 3.65V+ down to 2.1V end. what would you contest? is there something similar to certification that cells have the specific capacity? is it possible that the capacity will increase when you cycle them several times before you totally discharge them rather than totally discharging them on the very first cycle?

you should not be on this thread anyway since this guy just started the thread to trash the A123 cells he bot on ebay but he could not test them and made obviously distorted statements that the cells would not charge even though his video proved otherwise.

[Pure]

Considering what these cells are, second hand factory rejects, I would still be happy with those numbers. They are still large prismatic A123s and should have no problems giving you a solid 17Ah run.

[slawek]

what equipment? how did you calibrate it?

Just simple Hyperion EOS0720 charger.

why did you only charge to 3.6 and shut off at 2.5 when everyone else uses 3.65V+ down to 2.1V end.

These parameters are suggested by charger, the same like for LiPo 3-4.2V, so I assume hyperion company know what they are doing. And who is everyone else? Maybe just You?
look at the characterystic of A123 system, this is for cylindrical but, I do not think there is much difference for pouch cell except capacity. Do you see how steep is at the end of discharge? How many mAh do you think is possible to get from range 2,5V - 2,1V? 20mAh? 50mAh? I can assure you not to much. Some of my cells are missing more than 0,5Ah and even close 1Ah. What with shortening life when I abuse them? The same story with charging.

what would you contest?

Maybe you did not read my post. But how about missing Ah from what is advertised?

is there something similar to certification that cells have the specific capacity?

Unfortunately no. My assumption are base only on pdf document from a123system.com

is it possible that the capacity will increase when you cycle them several times before you totally discharge them rather than totally discharging them on the very first cycle?

You know, hard to say. I only cycle the weakest 3 times. Capacity results are almost identical.

you should not be on this thread anyway since this guy just started the thread to trash the A123 cells he bot on ebay but he could not test them and made obviously distorted statements that the cells would not charge even though his video proved otherwise.

Sorry but I think this forum is to help each other, not to fight and kicking me off. How about my effort to and work I have done to share with others? Is it worthless for you? I have no intention to hijack his thread. I just think is much easy to find more info about A123 if they are in one thread, not to spread in hundreds. And I had no problems to belief him that these cells would not charge, like others does.
*****************************************************************

Considering what these cells are, second hand factory rejects, I would still be happy with those numbers. They are still large prismatic A123s and should have no problems giving you a solid 17Ah run.

Probably you right. Dispute might be on for many weeks and I could not do anything with these battery. At least now anyone who buy from a123rc will know what to expect from them.

[parabellum]

I need guys your advice. Is it worth opening dispute?

Thanks for the info. Opening a dispute will not help and just cost you time, nerves and time again, but torment them a little via mail is recommendable, so at least they know what they are selling and how satisfied customers are.

[agniusm]

Slawek, you are most welcome to post your info here, thanks for that and your time. Dont pay attention to Dnmun. Hes the only one trashing this thread. I would not go Paypal route if i were you and had cells you have. First, they most likely are rejects and you did not paid 95USD a piece? Thats what mavizen charges for genuine a123 cells. So if you have solid 17AH and paid more than twice less it is still a good deal as you get high discharge current.
If you will start with paypal the outcome is unknown and you might loose at the end. For me a bit different story as i have nothing to loose any more, most cells i have received where dead, and it takes 2 moths to go trough paypal claim. I would keep them, in the end you would loose on shipping and possibly will not get something better. As for cycle life, nobody could be 100% sure even with genuine cells.

[agniusm]

Hi, a bit of update on my case. The guy from victpower, Robert contacted me today morning saying he shipped other cells to me. I'll be damned, never expected that to happen. All in all things started moving and looks like i will have some sort of proper cells in the end. At this moment i am thinking on buying a lab PSU to charge test single cells. I dont want to spend fortune on it and perhaps someone with more knowledge can advice if this one will suit me: http://www.multimeterwarehouse.com/hy1803d.htm

[Pure]

I'm not sure of your budget, but if you can afford it, go for it. But really all you need is a decent charger, a volt meter, and a way to discharge your cells that can actually draw a good deal of amps. Most common and easy (cheap) way to do this is to wire up some 12 volt halogen car light. First in series to get your desired voltage draw, then in parallel to reach your amp draw.

[parabellum]

Lab PSU is a good thing to have, but I would go for RC charger as well. Charge/Discharge cycling with RC charger is easy, non time consuming and controlled by the charger (you don't have to sit there watching).
Here is 1 good source. http://www.hobbyking.com/hobbyking/stor ... sortlist=P
The best one (off this list) is Icharger 3010b, but something like Eco Eight will do the job as well.

[agniusm]

Thanks. The price of that icharger is a bit high @176USD + add shipping, TAX and it is 200USD+ charger. Another thing to be able to use it i need 30VDC source, is is not running on mains. I can gen that lab PSU for 56USD with no shipping or TAX. I was just wandering if it is decent enough for the task (charging)

[parabellum]

Thanks. The price of that icharger is a bit high @176USD + add shipping, TAX and it is 200USD+ charger. Another thing to be able to use it i need 30VDC source, is is not running on mains. I can gen that lab PSU for 56USD with no shipping or TAX. I was just wandering if it is decent enough for the task (charging)

They have variable source V. I charger is 4.5V-38V. I normally use PC PSU for 10-20 US, and use 12V line, depending on PSU 20-40amps in this price range.
I have also 2 of this chargers. 36U$ and they work fine to, source V 11-18V. You can use Lab supply to feed them.http://www.hobbyking.com/hobbyking/stor ... _acc_.html

[circuit]

Be careful with iCharger 3010B, one almost burned my home. My review is second on hobbyking..

[Ypedal]

I love my 3010B..