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CALB quality slipping?

37K views 121 replies 22 participants last post by  JRP3 
#1 ·
Two recent cell deliveries that came with a large resistance spread, some sloppy looking cell construction, cells out of sequence, and questionable crating, have me wondering if CALB cell quality is not as good as it used to be. My order from three years ago was much more closely grouped and packaged better than these two orders:

http://www.diyelectriccar.com/forums/showthread.php/1930-model-roadster-build-59659p33.html

Has anyone else seen similar resistance spread and sloppy cell construction?
 
#31 ·
Can you point me more specifically to what you are talking about, onegreenev? I just watched as much of the latest issue as I could stand and all I saw on the subject of swelling was another attempt at casting A123 pouch cells ending as a bloated disaster.

I have a hard time seeing how my cells are going to swell with 1/4 inch aluminum end plates being strapped together with 1/2 inch wide stainless steel banding.

My understanding is that swelling allows gas space between the positive and negative plates. This make the ion path longer as the Lithium ions have to travel across the surface of the electrolyte on one plate until they reach an electrolyte connection to the other plate. Clamping the swelling out (which I have seen demonstrated) is supposed to push some of the gas out from between the plates and distribute what is left so that there can be more points of electrolyte contact. It can help reduce the cells internal resistance some, but not having been gassed internally is better.

I'm not overcharging, over discharging, or giving my cells any chance to swell. They continue to dish out 6C peak on demand while holding at or above 2.7 vpc (360 amps from 60 amp hour cells made in 2010.) I set my low voltage light at 103 volts for a 38 cell pack. Unless it has been cold I cannot make that light. My controller isn't set to cut back until the voltage gets down to 95 volts so it isn't limiting current before the warning light lights.
 
#32 ·
"They continue to dish out 6C peak on demand while holding at or above 2.7 vpc (360 amps from 60 amp hour cells made in 2010.) I set my low voltage light at 103 volts for a 38 cell pack. Unless it has been cold I cannot make that light. My controller isn't set to cut back until the voltage gets down to 95 volts so it isn't limiting current before the warning light lights."

I'm planning to use 100 60Ah cells(Sinopoly's smaller and lighter 60Ah(B) size cells if they manage to show up here), if it is difficult to get them to sag to 2.7v at 360amps, my 1900 pound car(pre-conversion) is going to fly! 270v * 360a = 97200kw. I'll take it.
 
#33 ·
Jack Rickard keeps trying, and repeatedly failing, to cast the A123 pouch cells into a solid block. It's obviously a bad idea since most of them seem to fail in the same manner, but he won't give it up. His weak layer of expanding foam plastic certainly can't provide any substantial force the way a real strapping system does, so it's no example of anything, other than a bad design.
 
#36 ·
I just saw the latest episode of EVTV and he blew up his brand new $900 12v 200ahr battery. Apparently he put it on the charger and then went to answer some emails. LOL. Where was the HVC? I am still pondering whether to go with a BMS or not but I would never put expensive Lithium cells on a charger or power supply without a HVC. I learned that lesson with some Headways and fortunately it was only a $40 lesson.
 
#34 ·
Hi guys,
I received 44 100AH Calib cells from Keegan at Calib Power in Pomona, Ca on 2/8/12 that had an internal resistance range of .28-.41 m ohm and a stated capacity of 106-108 Ah. I then decided to get one more cell, which came in with .32 Ohm and 107Ah capacity, and about 60 numbers off on the barcode, but similar on the S/N. I also noticed that the bar code numbers were sequential, but the S/N on the cells were all over the place. Don't know what that means, or if it has any bearing on when the cells were manufactured. My cells were all flat/ not swelled and were the same color. The cell spec chart had a date of 10/30/11, 3 months prior.
The cells were all about the same voltage3.30, except for one which was 3.28v(not the last one purchased). When I finally got around to topping off the cells,3 months later, most took about 50Ah to get to 3.55v, using my Icharger 110, rc charger @ 10A charge rate. The low cell, now 3.24v took 70Ah. This kind of worries me, but time will tell.
I drove the car, a 1991 Geo metro HB with a 5spd/ 9" ADC motor for the first time today and the batteries performed well. Starting in 4th gear and excelerating to 45mph briskly on flat ground with a max Amp draw of 142A, faster that the stock metro, showed the cells in the 3.2v range, at the low voltage sag point, according to my celllogs.
Joe
 
#35 ·
Thanks for the data, that's more inline with what I would expect, though the lower overall capacity compared to my three year old cells is disappointing, as is the slightly higher resistance spread. I've been hoping to replace my one slightly weaker cell and add two more to increase the voltage, but if they are of lower capacity and higher resistance than what I have I may not bother.
One thing I've been pondering, the 100ah and 180ah cells have always had the best energy density of all the CALB cells, and they are the most popular sizes, I wonder if they are made in a different factory or on a different line the the other sizes. Might explain some of the differences.
 
#50 ·
One thing I've been pondering, the 100ah and 180ah cells have always had the best energy density of all the CALB cells
Do you have a list of all the densities? I would expect larger cells to be better because less packaging/AH, but it would be interesting to know if it is more than just that, as you suggest.
 
#37 ·
A little late, but here's my similar recent experience with cells:

I received 45 130Ah cells about 6 months ago, internal resistance clustered in the low 0.30's.
Purchased 4 more from probably the same master shipment as the OP's, received week before last. All four have internal resistance in the mid to high .40's. 50%-ish higher.
Boy, the capacities are sure nice though.

Batt #....... Barcode............... IR.... V .....Cap
201009181 NSA1301204060045 0.45 3.310 145.6
201006644 NSA1301204060046 0.46 3.309 145.4
201009650 NSA1301204060047 0.47 3.311 145.7
2010061510 NSA1301204060048 0.48 3.309 145.4

Does anyone know what the "battery number" makeup is? It looks suspiciously like some kind of date code. The ones I got last year all started with 11. These all start with 2010. Mean anything?
 
#39 ·
Does anyone know what the "battery number" makeup is? It looks suspiciously like some kind of date code. The ones I got last year all started with 11. These all start with 2010. Mean anything?
All 262 cells from the bulk order produced in May of 2009 start with 09 for the battery number but the other digits don't seem to correlate to anything, they are all over the place, some with more digits than others, but all the barcode numbers are sequential and start with 0906, which was the shipping date, June 2009.
 
#42 ·
I don't know, millions of people watch Jackass too :D Even if the casting process "works" it does not allow for any real heat dissipation and it does not allow for individual cell replacement, which just seems foolish. Plus it adds weight and cost. I think your plan is much more reasonable, and closer to the way I would do it.
 
#45 ·
Well the heat from charging could be, but the one he used, the foaming one, I think would be no different, but it lives a happy life in an ugly box. I do not expect to do any single pouch replacement but my way would allow that. Or it will be built so one could if absolutely needed. Heat under normal use is not an issue either. Actually the cells should be warmed and be warm anyway. My life with my Leaf also confirms that. My battery temp never ever gets into the danger zone even in 110 degree weather and a full drive at freeway speed. In the winter they need to be warm. In the summer they really do not need cooled. Really. I agree with that. Much of this information is not just from one source. As time marches forward we are finding out what these cells will do. As for the A123, I hope we can find a safe secure way because I really want to buy a pile of them and use them. I like the power. I want to race too but do not want LiPO cells. I want LiFePO4 cells.

I will not be strapping my cells but I will build them in a snug box and pack those boxes in the larger box snugly. If you do not over charge you will NOT get swelling. If you do not over discharge you do not get swelling either. This has been proven already. I concur with the results. Those that swelling are over charging and usually using BMS and charging to the old max of 4 odd volts per cell. They also loose cells or bloat cells at the bottom too because of the ragged bottom. I know first hand that problem.

My pack was well secured and being secured no cell was visibly swollen but when I released the tension on the pack two cells bloated like two fat little pigs. So the strapping only HID the swelling issue. Not a good thing. If you do not know you have swelling how will you know if a problem is looming by over charging a little at a time.

So Jacks change of charging to only 3.5 is a good move but it gives a bit less AH per cell but not a huge hit because at 3.5 they are nearly charged anyway. I'm good with 3.5 volts per cell. I can do the change with my Elcon. The most I can charge to is 3.75 anyway overall. So some might go higher. I will check my charge discharge when my rendition is finalized. I will post the results even if a disaster arrises.

I like drama too. :)
 
#44 ·
Except that the 2011 cells started with 11, right? So I'd think the 2010's would start with 10. I also doubt they had cells sitting around unsold for two years. I'd be surprised if they changed the numbering system in 2010 and then changed it back, but I guess it's possible. My data sheet had the order build date and shipping date on it.
 
#46 ·
Warm cells increase performance but decrease lifespan. If you don't need the extra performance and would rather have a long pack life you're better off keeping cells cooler than warmer. Just because you see no degradation in the short term doesn't mean it isn't adding up over the long term.
 
#48 ·
I would rephrase that to HOT cells decrease lifespan. Not warm cells. My cells do not need to be hot. But they need to be warm. So far with a well balanced pack and even with hard driving I never had a HOT pack. Only warm. So far I still have full capacity in my Leaf. This is after 13,000 miles. Charged and driven daily. Once the cells are in the 70 degree range the cells provide real good power and range. In the cold it sucks. These cells live in the warm and do so quite well. I see LiFePO4 doing even better. I will know the exact capacity of my cells next time I go in for a check up. Should be real soon. If the lithium cells really lost capacity of 20% within 8 years or so you'd start seeing a loss of capacity right out of the gate. So far there is no difference. Driven of course within the safe confines of the cells abilities.

Warm cells are fine and live just fine. Hot cells! I have no clue. I know of no one that drives with HOT cells.

Pete :)
 
#51 ·
I drove the car, a 1991 Geo metro HB with a 5spd/ 9" ADC motor for the first time today and the batteries performed well. Starting in 4th gear and excelerating to 45mph briskly on flat ground with a max Amp draw of 142A, faster that the stock metro, showed the cells in the 3.2v range, at the low voltage sag point, according to my celllogs.-Joe G.
Oh, would we all have that type of performance/draw. I would call that about perfection (for the EV world).

In my 2,500# vehicle, I am expecting somewhere around 250-300 sustained amp draw with an AC50.

Miz
 
#52 ·
I would highly recommend using the gears a bit more. Not only will you see better efficiency, but it is MUCH easier on the motor/brushes. Just because you CAN do something does not mean you SHOULD.

2nd -3rd -4th is probably best, although it in some cars 3rd- 4th works pretty good, depending on factors such as gearing, weight, voltage, motor size, etc.

Nice job on the conversion! :)

Cheers
 
#55 ·
All this talk about lifetime is just pure speculation. Wishful thinking. No data. In general the more you stress a system the faster it fails, so you might expect that if you regularly run cells near the limit of their specs -high C discharge currents, high temperature, etc - they will have shorter life. But is this linear? Is there some threshold that has to be passed to show much effect? Who knows? No data.
Well actually there is lots of DATA. For the Leaf we have 1+ years. Jack Rickard has like 4 years. So far I'd say that the capacity loss is very non-linear. VERY. So that points to somewhere down the line we may actually start seeing a loss. OR the loss IS linear and its so slow that it will take a very very long time to start seeing the losses.

But don't say there is NO DATA. Far from NO DATA.

I do agree to not abuse the cells.
 
#58 ·
It's interesting with the Leaf because the guys on the Leaf forum have mixed results, there are a couple of people who have lost 1 bar of range(if I remember the forum attributed it to 100% charging using most of the capacity during the commute in a very hot climate) already and people with higher mileage and smaller DOD's have no perceived losses. To me it's expected but then again there is a luck of the draw which seems to be a clear thing for the Toyota and Honda hybrid users with the NiMh packs, different chemistry but you still get lucky or you don't in some cases.

At least with the prismatic cells if you get unlucky, the situation is isolated to a cell or a few while the others are fine, otherwise it is a conditional thing.
 
#60 ·
Hey Ziggy,
I'm using a Cycle analyst meter that is reading the current thru a 0.25 m Ohm shunt between the Neg battery terminal and the negitive side contactor. I've verified the shunts readings with my DC clamp Amp meter. The Amps are low due to the combination of a big motor, little light car, and 144V pack. The negitive Amp reading is due to inductance in the meter wires, not regen.
Joe
 

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#62 ·
The Amps are low due to the combination of a big motor, little light car, and 144V pack. The negitive Amp reading is due to inductance in the meter wires, not regen.
Joe
Sounds like you're getting some great performance. Have you done any experimenting to eliminate that inductance? My JDL shows some anomalous readings that prevent me from AH counting during a charge and I'm wondering if that may be part of the cause.
 
#63 ·
I just received my order of 52 CALB 100Ah cells and installed 50 of them in my 96 Solectria Force. I have yet to measure the internal resistance (I'll get to it eventually) But the cells look perfectly fine. I charged them up to 3.44V per cell sitting, and I'm reading a little over 125A on my controller's sense shunt. I'm pretty happy with that, but is that normal? I know that most of the lithiums come higher than they are rated, but I was surprised to see 25% more capacity. I'll have to verify my readings once I figure out what's wrong with my other built in ammeter. (Open somewhere in the circuit.)
 
#65 ·
I did not - I ordered them from Evolve Electrics, but they shipped from Calib. The data sheet is probably still in the box - I looked through one, and (I thought) I didn't see any useful info, so I just put them all in one box and continued with the 'manual' labor of moving the cells. I can check the sheet when I get home.
 
#66 ·
Overall lessons learned from a Lithium cell purchase:

Call/email warehouse. Confirm cells are in stock (for sure). Nail down a ship date.

Then do wire fund transfer immediately. Get cells. Painless.

That is the most secure, safe way I know.



Avoid paying for a possible future date and be wary of vague answers.

Some people get really busy after you paid the funds and do not return emails in a timely manner. In this day and age, there is absolutely no excuse for it. The truth is they didnt want to answer you.

AND if any of the parameters of a business deal change after you paid, cancel and get a refund immediately. Especially if dealing with a foreign shipment. Some businesses use that as a sales tactic to up the order or to "Bait and Switch" you to something else you do not really want, they just have it to sell.

Miz
 
#69 ·
you are saying CALB's "resistance" test is worthless?
Then why was it even included?
It's not just CALB. Roughly, 70 % of Li-ion spec sheets give the 1 kHz impedance, 5 % give true DC resistance, and the rest give nothing.

Why AC impedance? Because cell manufacturers have ready access to equipment that can measure AC impedance.

Why at 1 kHz? because the impedance of Li-ion cells has a 2-lobe shape, and there is a dip at around 1 kHz, so the numbers look better there. Also, at 1 kHz the impedance is more consistent than at other frequencies.

Why not DC resistance? Because it varies a lot, from cell to cell, as SOC changes, as temperature changes, and as the cell ages. And because they may not know how to measure it, or do not have access to equipment that does so.

Why does CALB publish each cell's AC impedance? Because it gives the user a sense that the manufacturer is thorough and therefore it imparts a sense confidence in the user.

Why does CALB ship cells with such a wide variance of AC impedance? Because those values are all well below their self-imposed cutoff threshold.

How do I know? I did a lot of research in the process of writing the Li-ion BMS book. Still, there are some holes in my understanding, so please forgive me if I missed something.

Davide
 
#70 ·
That's an interesting point which needs to be cross checked and verified. Certainly something seems to have changed in the cell manufacturing to increase the "resistance range", however it was tested. Could be just a change in the way they are testing, and it could indeed be meaningless. I think Tomofreno had extensive voltage plots under load which could be correlated to each serial number and spec'd resistance.
 
#73 ·
109-111Ah. I should've realized. My controller has been having issues, and it's sitting in my living room floor right now so I can work on it. I think you have to set the battery voltage, and it uses that and an internal reference to measure the current. I sure wish I knew more about these stupid UMOC440 controllers.
 
#74 ·
We could actually over think this thing...LOL

OK, Maybe the AC test might not reflect the DC test, but it might have some bearing on cell condition as manufactured and by that a grouping criteria.

Either way, I'm sticking with my plan.

1.Figure my average daily usage and by that my pack size.
2.Then oversize the pack 1/3 rd.
3.Buy from a known company.
4.Buy all pack cells at the same time. (maybe same batch)
5.Monitor cells in the beginning to find one that deviates, then install a monitor.

I am a car guy, I always watch my toys closely and do not abuse them.

If I lose a cell or two, It is my fault for ignoring advice.

Miz
 
#79 ·
Just to confuse things even more, I got this e-mail response from the US CALB distributor a month ago when I inquired about the future availability of the 130Ah cells:
"CALB still product SE130AHA model, we still have some stock in our Pomona, CA warehouse. Those cells were just arrived in 2 weeks ago.

Please feel free to contact me if you want to order.

Thanks,

[FONT=verdana,sans-serif]Keegan Han[/FONT]
[FONT=verdana,sans-serif]Sales Director
keegan@calibpower.com
Tel: 909-865-8809
Cell: 626-383-2957 "

[/FONT]
 
#80 ·
Just to confuse things even more, I got this e-mail response from the US CALB distributor a month ago when I inquired about the future availability of the 130Ah cells:
"CALB still product SE130AHA model, we still have some stock in our Pomona, CA warehouse. Those cells were just arrived in 2 weeks ago.

Please feel free to contact me if you want to order.

Thanks,

[FONT=verdana,sans-serif]Keegan Han[/FONT]
[FONT=verdana,sans-serif]Sales Director
keegan@calibpower.com
Tel: 909-865-8809
Cell: 626-383-2957 "

[/FONT]
Sorry to confuse you. Actually, 130AH battery is not general mass production anymore. We cannot promise the stock of 130AH ones everytime you want.
 
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