self-discharge of CALB 180Ah LiFePO4 cells

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self-discharge of CALB 180Ah LiFePO4 cells

Cor van de Water
Since about 6 months I have been testing the self-discharge of
a bunch of blue CALB LiFePO4 cells.
The good news is that after half a year of sitting, their
average voltage has changed from the (parallel) charge voltage
of 3.00V (meaning that they were charged to approx 10% SoC to
allow me to see how quickly they would fall off again, as the
voltage changes are larger to wards the extreme ends of the
charging curve) (after which I disconnected them to measure the
individual self-discharge of just each cells by themselves by
occasionally connecting a DVM to check and record voltage by hand)
to a self-discharged voltage of between 2.78 and 2.86V.
The current highest cell has the lowest self-discharge, losing
only about 80mV in that half year, while the fastest self-discharging
cell has lost almost double that voltage - 140mV
Note that this is not from the original 3.00V but from their state a
few weeks after I disconnected them, when I started recording voltages.
So, while the sitting of a cell over a half year (in winter)
apparently removes less than 10% of the charge, there definitely is
a marked difference in self-discharge between cells of almost 100%
higher discharge for the worst cell than the best cell in this sample
set of 16 cells.

I thought this might be of interest to some here.

Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: [hidden email]    Private: http://www.cvandewater.com
Skype: cor_van_de_water     XoIP: +31877841130
Tel: +1 408 383 7626        Tel: +91 (040)23117400 x203
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Re: self-discharge of CALB 180Ah LiFePO4 cells

Cruisin
After selling CALB cells for over 5 years and using them in my own conversion, I can tell you from experience the following. At least 15% of the cells will change so much in the first year the BMS will react to your disadvantage of early charging termination and early over discharging. A one year warranty that is promised is hocus. the second year will experience a 10% failure with no warning of a cell. This makes your car unusable. Further experience with other Chinese cells is no better, or worse. I now sell and use the Nissan Leaf module that is half the price and so far no failures like the CALB. I would not ever recommend a CALB cell to any customer. Those that are pushing the cells like EVTV have inventory they want to unload before their is no more demand for Chinese cells. My customers who have converted to the Volt and Leaf cells, made by the same S Korean manufacturer, are really happier with the results. No more stagnant at rest  loses that you have experienced. Look at what cells are used in the popular plugin cars that are required to provide a 8 year warranty in California, no Phosphate. CALB would be out of business if required to provide a 8 year warranty. They don't even recognize their one year warranty. You wonder why you are having problems, wake up and smell the coffee.
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Re: self-discharge of CALB 180Ah LiFePO4 cells

Willie2
On 04/20/2014 06:05 PM, Cruisin wrote:
> experience with other Chinese cells is no better, or worse. I now sell and
> use the Nissan Leaf module that is half the price and so far no failures
> like the CALB. I would not ever recommend a CALB cell to any customer. Those
>
I can tell you that my Leaf battery capacity was down to about 60% in
two years and about  20k miles.  I have a TS LFP pack about 6 years old
with about 50k miles and is down to about 80%.  The Leaf battery, of
course, was degraded by a horrible summer but the TS apparently not at all.
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Re: self-discharge of CALB 180Ah LiFePO4 cells

jerry freedomev
In reply to this post by Cruisin
Hi Cruisin and All,

         Until now I've stuck with lead because the problems you mentioned and more importantly the cost of new cells.

         Now I know totaled Leaf's are around means I'm finally going Lithium mostly because they cost less. 

         Do you or anyone have pics of how to make smaller packs of them, hints, etc I can check out?

          I chased the ones I mentioned before down selling a mile away from me but it turned out to be a third party advertising old items /wrecked cars in this case trying to conned you into buying crash reports on them.  But they had already sold in real life.

         For me a Leaf's battery pack will give my lightweight EV's 250-350 miles of range likely powering 3 of them.  If I want to all in with the Lumberghini and it is designed to hold 720lbs of lead so it can, put them all in it would 250 mile range or so though 100 miles worth and a DC generator is a lighter, better choice.

         Just getting the back deck, rollbar and the rest of the chassis done, then on to the body  next week.  I decided I wanted more crash protection that took a bit to figure out how to do it light took a bit of time but worth it.  Hopefully a totaled Leaf will come up before I get done.

         So I'm joining the auto auction with an alert when the next one comes up and bid on it.

         I can't edit so please edit any response. I can't  even change the subject anymore thanks to their 'improvements'. 

                                            Thanks,
                                                  Jerry Dycus

       

                                                                            
On Sunday, April 20, 2014 7:12 PM, Cruisin <[hidden email]> wrote:
 
After selling CALB cells for over 5 years and using them in my own
conversion, I can tell you from experience the following. At least 15% of
the cells will change so much in the first year the BMS will react to your
disadvantage of early charging termination and early over discharging. A one
year warranty that is promised is hocus. the second year will experience a
10% failure with no warning of a cell. This makes your car unusable. Further
experience with other Chinese cells is no better, or worse. I now sell and
use the Nissan Leaf module that is half the price and so far no failures
like the CALB. I would not ever recommend a CALB cell to any customer. Those
that are pushing the cells like EVTV have inventory they want to unload
before their is no more demand for Chinese cells. My customers who have
converted to the Volt and Leaf cells, made by the same S Korean
manufacturer, are really happier with the results. No more stagnant at rest
loses that you have experienced. Look at what cells are used in the popular
plugin cars that are required to provide a 8 year warranty in California, no
Phosphate. CALB would be out of business if required to provide a 8 year
warranty. They don't even recognize their one year warranty. You wonder why
you are having problems, wake up and smell the coffee.



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Editing in Yahoo mail, was: self-discharge of CALB 180Ah LiFePO4 cells

Cor van de Water
Jerry,
I see you have a Yahoo email address.
If you use the improved Yahoo website to edit your reply,
then the header of the email has a small chevron-pointing-down
in front of the title of the email when you are replying,
immediately above the text edit window.
Click on that chevron to get the selection "Edit Subject"
and you can change the title of the email.
Click on the "message history" that is showing at the bottom
of the text edit window in grey letters to see the mail
that you are replying to and this also allows you to edit
(trim or select) the words you want to include in your reply.

Success,

Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: [hidden email]    Private: http://www.cvandewater.com
Skype: cor_van_de_water     XoIP: +31877841130
Tel: +1 408 383 7626        Tel: +91 (040)23117400 x203



-----Original Message-----
From: [hidden email] on behalf of jerry freedomev
Sent: Sun 4/20/2014 6:21 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] self-discharge of CALB 180Ah LiFePO4 cells
 
Hi Cruisin and All,

         Until now I've stuck with lead because the problems you mentioned and more importantly the cost of new cells.

         Now I know totaled Leaf's are around means I'm finally going Lithium mostly because they cost less. 

         Do you or anyone have pics of how to make smaller packs of them, hints, etc I can check out?

          I chased the ones I mentioned before down selling a mile away from me but it turned out to be a third party advertising old items /wrecked cars in this case trying to conned you into buying crash reports on them.  But they had already sold in real life.

         For me a Leaf's battery pack will give my lightweight EV's 250-350 miles of range likely powering 3 of them.  If I want to all in with the Lumberghini and it is designed to hold 720lbs of lead so it can, put them all in it would 250 mile range or so though 100 miles worth and a DC generator is a lighter, better choice.

         Just getting the back deck, rollbar and the rest of the chassis done, then on to the body  next week.  I decided I wanted more crash protection that took a bit to figure out how to do it light took a bit of time but worth it.  Hopefully a totaled Leaf will come up before I get done.

         So I'm joining the auto auction with an alert when the next one comes up and bid on it.

         I can't edit so please edit any response. I can't  even change the subject anymore thanks to their 'improvements'. 

                                            Thanks,
                                                  Jerry Dycus

       

                                                                            
On Sunday, April 20, 2014 7:12 PM, Cruisin <[hidden email]> wrote:
 
After selling CALB cells for over 5 years and using them in my own
conversion, I can tell you from experience the following. At least 15% of
the cells will change so much in the first year the BMS will react to your
disadvantage of early charging termination and early over discharging. A one
year warranty that is promised is hocus. the second year will experience a
10% failure with no warning of a cell. This makes your car unusable. Further
experience with other Chinese cells is no better, or worse. I now sell and
use the Nissan Leaf module that is half the price and so far no failures
like the CALB. I would not ever recommend a CALB cell to any customer. Those
that are pushing the cells like EVTV have inventory they want to unload
before their is no more demand for Chinese cells. My customers who have
converted to the Volt and Leaf cells, made by the same S Korean
manufacturer, are really happier with the results. No more stagnant at rest
loses that you have experienced. Look at what cells are used in the popular
plugin cars that are required to provide a 8 year warranty in California, no
Phosphate. CALB would be out of business if required to provide a 8 year
warranty. They don't even recognize their one year warranty. You wonder why
you are having problems, wake up and smell the coffee.



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Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.
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Re: self-discharge of CALB 180Ah LiFePO4 cells

Al-57
In reply to this post by Cruisin
I have to agree with Cruisin. I took a chance on Lithium with CALB cells,
and man have I got burned. My pack is just shy of 2 years old. It has been
very lightly used for only 10,000 miles and perhaps 200 cycles. The cells
are supposed to be 100Ah. Even when new I bench tested a few at .3C and only
got 95Ah. Now the pack is below 80AH according to my BMS. At this point I
have no idea what my range will be each time I drive as I have had several
cells lose 25% capacity out of nowhere. So much for the cheaper than lead
mantra.

1000+ cycles - Not a chance
100,000 miles - You're kidding right?
10 years - In your dreams.

Al


CALB cells (and many others) are typical Chinese junk.
----- Original Message -----
From: "Cruisin" <[hidden email]>
To: <[hidden email]>
Sent: Sunday, April 20, 2014 7:05 PM
Subject: Re: [EVDL] self-discharge of CALB 180Ah LiFePO4 cells


> After selling CALB cells for over 5 years and using them in my own
> conversion, I can tell you from experience the following. At least 15% of
> the cells will change so much in the first year the BMS will react to your
> disadvantage of early charging termination and early over discharging. A
> one
> year warranty that is promised is hocus. the second year will experience a
> 10% failure with no warning of a cell. This makes your car unusable.
> Further
> experience with other Chinese cells is no better, or worse. I now sell and
> use the Nissan Leaf module that is half the price and so far no failures
> like the CALB. I would not ever recommend a CALB cell to any customer.
> Those
> that are pushing the cells like EVTV have inventory they want to unload
> before their is no more demand for Chinese cells. My customers who have
> converted to the Volt and Leaf cells, made by the same S Korean
> manufacturer, are really happier with the results. No more stagnant at
> rest
> loses that you have experienced. Look at what cells are used in the
> popular
> plugin cars that are required to provide a 8 year warranty in California,
> no
> Phosphate. CALB would be out of business if required to provide a 8 year
> warranty. They don't even recognize their one year warranty. You wonder
> why
> you are having problems, wake up and smell the coffee.

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Re: self-discharge of CALB 180Ah LiFePO4 cells

Bill Dube
In reply to this post by Cor van de Water
As I understand it, the self-discharge for LiFePO4 cells is effected by
a host of conditions, including state-of-charge.
As I recall, it hits a minimum at something like 60% SOC.

Abnormally high self discharge is never a good sign, regardless.

Bill D.


On 4/20/2014 4:04 PM, Cor van de Water wrote:

> Since about 6 months I have been testing the self-discharge of
> a bunch of blue CALB LiFePO4 cells.
> The good news is that after half a year of sitting, their
> average voltage has changed from the (parallel) charge voltage
> of 3.00V (meaning that they were charged to approx 10% SoC to
> allow me to see how quickly they would fall off again, as the
> voltage changes are larger to wards the extreme ends of the
> charging curve) (after which I disconnected them to measure the
> individual self-discharge of just each cells by themselves by
> occasionally connecting a DVM to check and record voltage by hand)
> to a self-discharged voltage of between 2.78 and 2.86V.
> The current highest cell has the lowest self-discharge, losing
> only about 80mV in that half year, while the fastest self-discharging
> cell has lost almost double that voltage - 140mV
> Note that this is not from the original 3.00V but from their state a
> few weeks after I disconnected them, when I started recording voltages.
> So, while the sitting of a cell over a half year (in winter)
> apparently removes less than 10% of the charge, there definitely is
> a marked difference in self-discharge between cells of almost 100%
> higher discharge for the worst cell than the best cell in this sample
> set of 16 cells.
>
> I thought this might be of interest to some here.
>
> Cor van de Water
> Chief Scientist
> Proxim Wireless Corporation http://www.proxim.com
> Email: [hidden email]    Private: http://www.cvandewater.com
> Skype: cor_van_de_water     XoIP: +31877841130
> Tel: +1 408 383 7626        Tel: +91 (040)23117400 x203
> _______________________________________________
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
>
>

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Re: self-discharge of CALB 180Ah LiFePO4 cells

Rush Dougherty
In reply to this post by Al-57
Who did you buy them from?

Rush
www.TucsonEV.com

> -----Original Message-----
> From: [hidden email] [mailto:[hidden email]] On
Behalf
> Of Al
> Sent: Sunday, April 20, 2014 7:42 PM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] self-discharge of CALB 180Ah LiFePO4 cells
>
> I have to agree with Cruisin. I took a chance on Lithium with CALB cells,
and
> man have I got burned. My pack is just shy of 2 years old. It has been
very
> lightly used for only 10,000 miles and perhaps 200 cycles. The cells are
> supposed to be 100Ah. Even when new I bench tested a few at .3C and only
got
> 95Ah. Now the pack is below 80AH according to my BMS. At this point I have
no
> idea what my range will be each time I drive as I have had several cells
lose

> 25% capacity out of nowhere. So much for the cheaper than lead mantra.
>
> 1000+ cycles - Not a chance
> 100,000 miles - You're kidding right?
> 10 years - In your dreams.
>
> Al
>
>
> CALB cells (and many others) are typical Chinese junk.
> ----- Original Message -----
> From: "Cruisin" <[hidden email]>
> To: <[hidden email]>
> Sent: Sunday, April 20, 2014 7:05 PM
> Subject: Re: [EVDL] self-discharge of CALB 180Ah LiFePO4 cells
>
>
> > After selling CALB cells for over 5 years and using them in my own
> > conversion, I can tell you from experience the following. At least 15%
of
> > the cells will change so much in the first year the BMS will react to
your
> > disadvantage of early charging termination and early over discharging. A
> > one
> > year warranty that is promised is hocus. the second year will experience
a
> > 10% failure with no warning of a cell. This makes your car unusable.
> > Further
> > experience with other Chinese cells is no better, or worse. I now sell
and

> > use the Nissan Leaf module that is half the price and so far no failures
> > like the CALB. I would not ever recommend a CALB cell to any customer.
> > Those
> > that are pushing the cells like EVTV have inventory they want to unload
> > before their is no more demand for Chinese cells. My customers who have
> > converted to the Volt and Leaf cells, made by the same S Korean
> > manufacturer, are really happier with the results. No more stagnant at
> > rest
> > loses that you have experienced. Look at what cells are used in the
> > popular
> > plugin cars that are required to provide a 8 year warranty in
California,

> > no
> > Phosphate. CALB would be out of business if required to provide a 8 year
> > warranty. They don't even recognize their one year warranty. You wonder
> > why
> > you are having problems, wake up and smell the coffee.
>
> _______________________________________________
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> For EV drag racing discussion, please use NEDRA
> (http://groups.yahoo.com/group/NEDRA)
>
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2014.0.4569 / Virus Database: 3882/7371 - Release Date: 04/20/14



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Re: self-discharge of CALB 180Ah LiFePO4 cells

David Nelson-5
In reply to this post by Al-57
Al, what voltage range did you use your cells at? What was max voltage
and what was the charging current at that voltage? What was the
minimum voltage at rest? I ask because I have kept my cells between 3V
at rest and no higher than 3.5V under 0.001C charge rate for most of
their life and I'm not seeing what you are seeing. My cells are TS
cells manufactured 9-2009 and have been in service since 1-2010.

On Sun, Apr 20, 2014 at 7:42 PM, Al <[hidden email]> wrote:

> I have to agree with Cruisin. I took a chance on Lithium with CALB cells,
> and man have I got burned. My pack is just shy of 2 years old. It has been
> very lightly used for only 10,000 miles and perhaps 200 cycles. The cells
> are supposed to be 100Ah. Even when new I bench tested a few at .3C and only
> got 95Ah. Now the pack is below 80AH according to my BMS. At this point I
> have no idea what my range will be each time I drive as I have had several
> cells lose 25% capacity out of nowhere. So much for the cheaper than lead
> mantra.
>
> 1000+ cycles - Not a chance
> 100,000 miles - You're kidding right?
> 10 years - In your dreams.
>
> Al
>
>
> CALB cells (and many others) are typical Chinese junk.
> ----- Original Message ----- From: "Cruisin" <[hidden email]>
> To: <[hidden email]>
> Sent: Sunday, April 20, 2014 7:05 PM
> Subject: Re: [EVDL] self-discharge of CALB 180Ah LiFePO4 cells
>
>
>
>> After selling CALB cells for over 5 years and using them in my own
>> conversion, I can tell you from experience the following. At least 15% of
>> the cells will change so much in the first year the BMS will react to your
>> disadvantage of early charging termination and early over discharging. A
>> one
>> year warranty that is promised is hocus. the second year will experience a
>> 10% failure with no warning of a cell. This makes your car unusable.
>> Further
>> experience with other Chinese cells is no better, or worse. I now sell and
>> use the Nissan Leaf module that is half the price and so far no failures
>> like the CALB. I would not ever recommend a CALB cell to any customer.
>> Those
>> that are pushing the cells like EVTV have inventory they want to unload
>> before their is no more demand for Chinese cells. My customers who have
>> converted to the Volt and Leaf cells, made by the same S Korean
>> manufacturer, are really happier with the results. No more stagnant at
>> rest
>> loses that you have experienced. Look at what cells are used in the
>> popular
>> plugin cars that are required to provide a 8 year warranty in California,
>> no
>> Phosphate. CALB would be out of business if required to provide a 8 year
>> warranty. They don't even recognize their one year warranty. You wonder
>> why
>> you are having problems, wake up and smell the coffee.
>
>
> _______________________________________________
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> For EV drag racing discussion, please use NEDRA
> (http://groups.yahoo.com/group/NEDRA)
>



--
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http://evalbum.com/1328
http://www.levforum.com
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Re: self-discharge of CALB 180Ah LiFePO4 cells

Jukka Järvinen-2
It really boils down to tow facts. 1st: cells are sent away from the
production before they have been aged to find out defects. It's considered
to be unreasonable practice since it takes a long time and storage space.
2nd: the first formation steps build most of the cell but there is that 5%
of undone which is disregarded for better profits. I'd have to call it
intentional deception. But adaptive BMS takes care of it (if
available). When dealing with product integrated cell manufacturing these
issues are counted in. No reason to even compare Leaf and bulk prismatic.
Leaf cells are already formatted to end with specific BMS. Leaf failures
with LMO was cost saving idea with passive design (which works in most
places). Buy Calb/Winston/Sinopoly/Liyuan and you really need very good BMS
to take care of those last steps of manufacturing. Should I again say
something to about the No-BMS cult? -Jukka


2014-04-21 8:47 GMT+03:00 David Nelson <[hidden email]>:

> Al, what voltage range did you use your cells at? What was max voltage
> and what was the charging current at that voltage? What was the
> minimum voltage at rest? I ask because I have kept my cells between 3V
> at rest and no higher than 3.5V under 0.001C charge rate for most of
> their life and I'm not seeing what you are seeing. My cells are TS
> cells manufactured 9-2009 and have been in service since 1-2010.
>
> On Sun, Apr 20, 2014 at 7:42 PM, Al <[hidden email]> wrote:
> > I have to agree with Cruisin. I took a chance on Lithium with CALB cells,
> > and man have I got burned. My pack is just shy of 2 years old. It has
> been
> > very lightly used for only 10,000 miles and perhaps 200 cycles. The cells
> > are supposed to be 100Ah. Even when new I bench tested a few at .3C and
> only
> > got 95Ah. Now the pack is below 80AH according to my BMS. At this point I
> > have no idea what my range will be each time I drive as I have had
> several
> > cells lose 25% capacity out of nowhere. So much for the cheaper than lead
> > mantra.
> >
> > 1000+ cycles - Not a chance
> > 100,000 miles - You're kidding right?
> > 10 years - In your dreams.
> >
> > Al
> >
> >
> > CALB cells (and many others) are typical Chinese junk.
> > ----- Original Message ----- From: "Cruisin" <[hidden email]>
> > To: <[hidden email]>
> > Sent: Sunday, April 20, 2014 7:05 PM
> > Subject: Re: [EVDL] self-discharge of CALB 180Ah LiFePO4 cells
> >
> >
> >
> >> After selling CALB cells for over 5 years and using them in my own
> >> conversion, I can tell you from experience the following. At least 15%
> of
> >> the cells will change so much in the first year the BMS will react to
> your
> >> disadvantage of early charging termination and early over discharging. A
> >> one
> >> year warranty that is promised is hocus. the second year will
> experience a
> >> 10% failure with no warning of a cell. This makes your car unusable.
> >> Further
> >> experience with other Chinese cells is no better, or worse. I now sell
> and
> >> use the Nissan Leaf module that is half the price and so far no failures
> >> like the CALB. I would not ever recommend a CALB cell to any customer.
> >> Those
> >> that are pushing the cells like EVTV have inventory they want to unload
> >> before their is no more demand for Chinese cells. My customers who have
> >> converted to the Volt and Leaf cells, made by the same S Korean
> >> manufacturer, are really happier with the results. No more stagnant at
> >> rest
> >> loses that you have experienced. Look at what cells are used in the
> >> popular
> >> plugin cars that are required to provide a 8 year warranty in
> California,
> >> no
> >> Phosphate. CALB would be out of business if required to provide a 8 year
> >> warranty. They don't even recognize their one year warranty. You wonder
> >> why
> >> you are having problems, wake up and smell the coffee.
> >
> >
> > _______________________________________________
> > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> > http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> > For EV drag racing discussion, please use NEDRA
> > (http://groups.yahoo.com/group/NEDRA)
> >
>
>
>
> --
> David D. Nelson
> http://evalbum.com/1328
> http://www.levforum.com
> _______________________________________________
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
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>
>
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Re: self-discharge of CALB 180Ah LiFePO4 cells

Cruisin
BMS is very important to the life of any Li-ion cells. Is there a production car not using BMS?. Bottom balance W/O BMS is a disaster waiting to come true. I didn't mention the difference in costs of cells like CALB and others compared to the NEW (not from wrecks) Leaf cells I sell. How about 48 modules = 24kw for $4800? Try to beat that with CALB, etc.
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Re: self-discharge of CALB 180Ah LiFePO4 cells

damon henry
So what BMS are people using with the batteries you are selling and how much does that add to the cost?  With your strong opinions about having to use a BMS I am surprised you are willing to sell the modules without an appropriate BMS as part of the deal.  Are you providing any warranty or after sale support?  It seems as if you are using lack of BMS and warranty support as a negative to the Chinese cells, yet wiling to let people walk right down the same path as long as they buy what you have to offer.
I hope to buy lithium for my truck some day and feel that even with their flaws the Chinese batteries are at least a known commodity at this time.  Buying raw cells meant for a Leaf or a Volt without the hardware or firmware they were designed to be used with sounds a little sketchy to me, if for nothing else, just for the lack of expertise available.  I remember how some of the first people to try the Chinese cells got burned back in the day :)  Now at least there is no lack of opinions about how to use them properly and plenty of real success stories.  
I remember David Nelson bringing his TS cells to my house to work on them together before he stuffed them into his Gizmo several years ago and I see that for his application, his cells and approach to maintaining them has worked out well.  

damon

> Date: Mon, 21 Apr 2014 05:38:33 -0700
> From: [hidden email]
> To: [hidden email]
> Subject: Re: [EVDL] self-discharge of CALB 180Ah LiFePO4 cells
>
> BMS is very important to the life of any Li-ion cells. Is there a production
> car not using BMS?. Bottom balance W/O BMS is a disaster waiting to come
> true. I didn't mention the difference in costs of cells like CALB and others
> compared to the NEW (not from wrecks) Leaf cells I sell. How about 48
> modules = 24kw for $4800? Try to beat that with CALB, etc.
>
>
>
> --
> View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/self-discharge-of-CALB-180Ah-LiFePO4-cells-tp4669067p4669085.html
> Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.
> _______________________________________________
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> http://lists.evdl.org/listinfo.cgi/ev-evdl.org
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>
     
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Re: self-discharge of CALB 180Ah LiFePO4 cells

Michael Ross
These arguments and anecdotal complaints never seem to cover all the
details.  Temperature of charge and discharge, charge and discharge rates,
fidelity to charging and discharging limits...

I am pretty sure you can take new LFP cells and treat them well with out
any BMS, and I am pretty sure you can ruin them with a BMS and improper
behavior.  Not to mention that BMS (at least the cheap small ones
appropriate for my little packs) are black boxes and not exactly
trustworthy.

I think you want to ensure a new pack has all good cells at the start.  I
am playing with a set of used and abused cells (40Ah TS).  I can't predict
anything about them, and won't make any broad claims about TS LFP cells
based on what I do.   I doubt a BMS would keep it running right, so I am
opting for bottom balancing and close attention for a while.  I plan to be
gentle with them, my charge rates are around 1C, will probably try to
operate between 20% and 80% SOC.

I think most OEM packs are doing this - sacrificing 40% of max charge in
favor of few failures- and their longevity is probably directly
attributable to this.



I don't think bottom balancing is cult-ish. (It IS rude to talk bout it
that way.) It is just complicated. There is more to care and feeding of Li
cells than just balancing and BMS.  Apparently, we can't assume that all
the cells we buy are good, so we have to deal with that.  We have to be
very careful comparing results, because there are so many fault modes, both
in operation and in measurement.

Blasting all use of Li cells versus PbSO4 is just silly, particularly for
smaller applications.  No way I am putting 60V of PbSO4 on my trike.




On Mon, Apr 21, 2014 at 11:27 AM, damon henry <[hidden email]>wrote:

> So what BMS are people using with the batteries you are selling and how
> much does that add to the cost?  With your strong opinions about having to
> use a BMS I am surprised you are willing to sell the modules without an
> appropriate BMS as part of the deal.  Are you providing any warranty or
> after sale support?  It seems as if you are using lack of BMS and warranty
> support as a negative to the Chinese cells, yet wiling to let people walk
> right down the same path as long as they buy what you have to offer.
> I hope to buy lithium for my truck some day and feel that even with their
> flaws the Chinese batteries are at least a known commodity at this time.
>  Buying raw cells meant for a Leaf or a Volt without the hardware or
> firmware they were designed to be used with sounds a little sketchy to me,
> if for nothing else, just for the lack of expertise available.  I remember
> how some of the first people to try the Chinese cells got burned back in
> the day :)  Now at least there is no lack of opinions about how to use them
> properly and plenty of real success stories.
> I remember David Nelson bringing his TS cells to my house to work on them
> together before he stuffed them into his Gizmo several years ago and I see
> that for his application, his cells and approach to maintaining them has
> worked out well.
>
> damon
>
> > Date: Mon, 21 Apr 2014 05:38:33 -0700
> > From: [hidden email]
> > To: [hidden email]
> > Subject: Re: [EVDL] self-discharge of CALB 180Ah LiFePO4 cells
> >
> > BMS is very important to the life of any Li-ion cells. Is there a
> production
> > car not using BMS?. Bottom balance W/O BMS is a disaster waiting to come
> > true. I didn't mention the difference in costs of cells like CALB and
> others
> > compared to the NEW (not from wrecks) Leaf cells I sell. How about 48
> > modules = 24kw for $4800? Try to beat that with CALB, etc.
> >
> >
> >
> > --
> > View this message in context:
> http://electric-vehicle-discussion-list.413529.n4.nabble.com/self-discharge-of-CALB-180Ah-LiFePO4-cells-tp4669067p4669085.html
> > Sent from the Electric Vehicle Discussion List mailing list archive at
> Nabble.com.
> > _______________________________________________
> > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> > http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> > For EV drag racing discussion, please use NEDRA (
> http://groups.yahoo.com/group/NEDRA)
> >
>
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>


--
Put this question to yourself: should I use everyone else to attain
happiness, or should I help others gain happiness?
*Dalai Lama *

Tell me what it is you plan to do
With your one wild and precious life?
Mary Oliver, "The summer day."

To invent, you need a good imagination and a pile of junk.
Thomas A. Edison<http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html>

A public-opinion poll is no substitute for thought.
*Warren Buffet*

Michael E. Ross
(919) 550-2430 Land
(919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone
(919) 631-1451 Cell
(919) 513-0418 Desk

[hidden email]
<[hidden email]>
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Re: self-discharge of CALB 180Ah LiFePO4 cells

EVDL Administrator
On 21 Apr 2014 at 12:34, Michael Ross wrote:

> I don't think bottom balancing is cult-ish. (It IS rude to talk bout it
> that way.) It is just complicated.

I can see why you might think it rude.  

The term "cult" might be a bit strong.  But personally, I do see an an
element of a sort of "religion" in some of the bottom-balancing folk. Others
may not feel the same way.

I may try BB someday.  But right now my sole experience with LiFePO4 is with
a conventional top-balancing BMS, and so far it's working very, very well
for me.  Based on the way things are going, if I put lithium in a road EV in
the near future, I'll use a well established BMS and not think twice.

David Roden - Akron, Ohio, USA
EVDL Administrator

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Re: self-discharge of CALB 180Ah LiFePO4 cells

David Nelson-5
On Mon, Apr 21, 2014 at 9:45 AM, EVDL Administrator <[hidden email]> wrote:

> On 21 Apr 2014 at 12:34, Michael Ross wrote:
>
>> I don't think bottom balancing is cult-ish. (It IS rude to talk bout it
>> that way.) It is just complicated.
>
> I can see why you might think it rude.
>
> The term "cult" might be a bit strong.  But personally, I do see an an
> element of a sort of "religion" in some of the bottom-balancing folk. Others
> may not feel the same way.

In all fairness, your statement can be equally applied to the "BMS
only" crowd. As Michael and Damon point out, this is not as simple as
one thing works and another thing doesn't. There are many parameters
to consider in how a battery pack has been treated before anything can
really be said about a particular method. I was fortunate enough to
get 40 good cells. Now that I have 4 years and 18k miles on my pack
and it is still going strong and is not getting out of balance with no
balancing being done on any charge, you can see why I question the
"requirement" of having a top balancing BMS whether it is active or
passive. I purposely chose to go without the top balancing BMS I
started out with because no one could show me the theoretical reason
to have a top balancing BMS and I couldn't find one in all the
researching I did either. For my climate and setup my data is still
showing that a BMS is not necessary. Maybe if I lived where Jukka
lives I would have different results. I know I'm not the only one with
great results with no BMS. Blanket statements from either "camp" make
them appear cultish.

It may be that, as Jukka pointed out about the formation charges, I
was actually fortunate to have very slowly (10A into 20 paralleled
100Ah cells) charged my cells to 4.00V initially and for a short time
after installation. Now I charge to 3.455V/cell average. I don't
charge if the case temp is at or below freezing, and I rarely
discharge past 70%DOD.

As for other types of lithium batteries besides LiFePO4, I can't say
for sure, I haven't tested or researched them enough.

--
David D. Nelson
http://evalbum.com/1328
http://www.levforum.com
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Re: self-discharge of CALB 180Ah LiFePO4 cells

Ruckus
In reply to this post by Cor van de Water
People are hard-wired for anecdotal experience to reign supreme.  Lead vs
Lithium, BMS vs. no BMS, Ford vs. Chevy, Coiled vs. daisy chain, skinny vs.
wide (tires or asses, does it matter?),  blonde vs. brunette, nerd vs.
jock, need I go on?

Any wise person can recognize there are advantages to all, each and every.
 And, yes, they all have issues.  But you have to choose one, don't you?

Blue CALBs placed at Pikes Peak.  Leaf Battery??  DNF...

Respect what works.






On Sun, Apr 20, 2014 at 4:04 PM, Cor van de Water <[hidden email]> wrote:

> Since about 6 months I have been testing the self-discharge of
> a bunch of blue CALB LiFePO4 cells.
> The good news is that after half a year of sitting, their
> average voltage has changed from the (parallel) charge voltage
> of 3.00V (meaning that they were charged to approx 10% SoC to
> allow me to see how quickly they would fall off again, as the
> voltage changes are larger to wards the extreme ends of the
> charging curve) (after which I disconnected them to measure the
> individual self-discharge of just each cells by themselves by
> occasionally connecting a DVM to check and record voltage by hand)
> to a self-discharged voltage of between 2.78 and 2.86V.
> The current highest cell has the lowest self-discharge, losing
> only about 80mV in that half year, while the fastest self-discharging
> cell has lost almost double that voltage - 140mV
> Note that this is not from the original 3.00V but from their state a
> few weeks after I disconnected them, when I started recording voltages.
> So, while the sitting of a cell over a half year (in winter)
> apparently removes less than 10% of the charge, there definitely is
> a marked difference in self-discharge between cells of almost 100%
> higher discharge for the worst cell than the best cell in this sample
> set of 16 cells.
>
> I thought this might be of interest to some here.
>
> Cor van de Water
> Chief Scientist
> Proxim Wireless Corporation http://www.proxim.com
> Email: [hidden email]    Private: http://www.cvandewater.com
> Skype: cor_van_de_water     XoIP: +31877841130
> Tel: +1 408 383 7626        Tel: +91 (040)23117400 x203
> _______________________________________________
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>


--
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Re: self-discharge of CALB 180Ah LiFePO4 cells

Al-57
In reply to this post by David Nelson-5
I purchased the cells directly from CALB in California.
I have a Lithiumate Pro BMS and follow CALB's recommendations. Charge to
3.60 if I need every bit of range, but usually charge to 3.50. Rarely go
below 3.00 at rest. 3.10 at rest is considered 80%DOD. The BMS calculates
the cell internal resistance in real time. There is 2:1 or 3:1 difference
between lowest and highest, that tells you that quality control is nil.
Early on I would smell a strong electrolyte odor in the battery box. I know
that is not right, I could not tell if one cell was leaking or many. If
going above 80%DOD or below 20%DOD causes faster deterioration, then you
would have to oversize your pack by quite a lot and keep it within the 80-20
range. I guess the OEM's are doing this.

Al

----- Original Message -----
From: "David Nelson" <[hidden email]>
To: "Electric Vehicle Discussion List" <[hidden email]>
Sent: Monday, April 21, 2014 1:47 AM
Subject: Re: [EVDL] self-discharge of CALB 180Ah LiFePO4 cells


> Al, what voltage range did you use your cells at? What was max voltage
> and what was the charging current at that voltage? What was the
> minimum voltage at rest? I ask because I have kept my cells between 3V
> at rest and no higher than 3.5V under 0.001C charge rate for most of
> their life and I'm not seeing what you are seeing. My cells are TS
> cells manufactured 9-2009 and have been in service since 1-2010.
>

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Articles, Pb Battery processing in MN; MN Limo company now has a Tesla

Christopher Meier



Bruce et al, a couple of interesting articles in the Minneapolis Star Tribune today.

Laid-off plant manager found a career that 'isn't hard work'
http://www.startribune.com/business/255834701.html 
CEO Vinny Vassallo of Vincent Limousine saves a bundle on gas and oil changes by ferrying customers in his Tesla electric car.

Eagan company finds new life for dead car batteries
http://www.startribune.com/business/255835601.html 
Gopher Resource’s plant in Eagan is one of the few plants left recycling and repurposing car batteries.
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Re: self-discharge of CALB 180Ah LiFePO4 cells

Mike Nickerson
In reply to this post by Al-57
Wow.  I have a pack of 45 ThunderSky 100Ah cells.  I used to feel they were
a distinct notch below cells like CALB.  Now, I'm not so sure.

I just crossed 26,000 miles in almost 4 years with my pack.  It has a range
of 50+ miles, but my typical commute is 23 miles, each way, with a recharge
at each end.  So, I've got about 1100 charge cycles in the pack.  For the
first two years, I parked the car all winter to work on it.  The last two
winters, I've driven it almost every day.  I've only parked it on days when
the snow was deep enough to cause problems for a low-slung sports car.

I'm running MiniBMS on each cell and top-balancing with shunts on each BMS
board.  I know from experience that the shunts are not enough to get the
pack in balance, but they are working to keep it in balance.  Also, when the
pack is properly balanced, the charger shuts off automatically, so the BMS
are just a safety measure on the high voltage side.

I have two cells that I abused badly within the first year.  My MiniBMS was
alerting, but I couldn't hear it at highway speeds.  I took the two cells to
0V.  I have been babying them for 3 years, and the same cells are still in
the pack, but I think they are starting to go.  I am looking for some spares
to replace them, if anyone is taking apart a ThunderSky 100Ah pack.

That episode was when I realized that my pack was 20% out of balance.  I had
to top up the low cells by 20Ah to bring them up to the high cells.  Once I
had that all worked out, the charger shut off automatically instead of the
BMS cutting AC power.  The shunts had been trying to balance the pack, but
they just didn't have time enough to make much difference in cell balance
when the charger was still in its bulk current phase.  Once the charger
tapers current, near the final voltage, the shunts have more chance to bring
things into balance.

Winter performance was very sluggish, but I've now got battery heaters now
that help quite a bit.

Mike
www.evalbum.com/2778


> -----Original Message-----
> From: [hidden email] [mailto:[hidden email]] On
> Behalf Of Al
> Sent: Sunday, April 20, 2014 8:42 PM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] self-discharge of CALB 180Ah LiFePO4 cells
>
> I have to agree with Cruisin. I took a chance on Lithium with CALB cells,
and
> man have I got burned. My pack is just shy of 2 years old. It has been
very

> lightly used for only 10,000 miles and perhaps 200 cycles. The cells are
> supposed to be 100Ah. Even when new I bench tested a few at .3C and only
> got 95Ah. Now the pack is below 80AH according to my BMS. At this point I
> have no idea what my range will be each time I drive as I have had several
> cells lose 25% capacity out of nowhere. So much for the cheaper than lead
> mantra.
>
> 1000+ cycles - Not a chance
> 100,000 miles - You're kidding right?
> 10 years - In your dreams.
>
> Al
>
>
> CALB cells (and many others) are typical Chinese junk.
> ----- Original Message -----
> From: "Cruisin" <[hidden email]>
> To: <[hidden email]>
> Sent: Sunday, April 20, 2014 7:05 PM
> Subject: Re: [EVDL] self-discharge of CALB 180Ah LiFePO4 cells
>
>
> > After selling CALB cells for over 5 years and using them in my own
> > conversion, I can tell you from experience the following. At least 15%
of
> > the cells will change so much in the first year the BMS will react to
your
> > disadvantage of early charging termination and early over discharging. A
> > one
> > year warranty that is promised is hocus. the second year will experience
a
> > 10% failure with no warning of a cell. This makes your car unusable.
> > Further
> > experience with other Chinese cells is no better, or worse. I now sell
and

> > use the Nissan Leaf module that is half the price and so far no failures
> > like the CALB. I would not ever recommend a CALB cell to any customer.
> > Those
> > that are pushing the cells like EVTV have inventory they want to unload
> > before their is no more demand for Chinese cells. My customers who have
> > converted to the Volt and Leaf cells, made by the same S Korean
> > manufacturer, are really happier with the results. No more stagnant at
> > rest
> > loses that you have experienced. Look at what cells are used in the
> > popular
> > plugin cars that are required to provide a 8 year warranty in
California,

> > no
> > Phosphate. CALB would be out of business if required to provide a 8 year
> > warranty. They don't even recognize their one year warranty. You wonder
> > why
> > you are having problems, wake up and smell the coffee.
>
> _______________________________________________
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Re: self-discharge of CALB 180Ah LiFePO4 cells

Jukka Järvinen-2
In reply to this post by David Nelson-5
The thing is, David, while you are still going strong and not even once
measured voltages from the pack during the 18k with a multimeter (naturally
you have measured. right?), the BMS-less use is for people who know how to
take care of their pack.

When a new born EV person reads through all this and decides to go without
(cost savings) theres a good chance for disaster. Very same applies with
BMS when it's installed wrong way or it's just piece of bad electronics.
LFP is forgiving but it dies also by million cuts. No monitoring means
"sudden accidents". It frankly is like driving without seat belts. No
crash, no problem.

What are the possible error scenarios which can lead to cell over discharge
and/or meltdown?
- loose connection on the cell pole
- loose connection inside the cell (corrosion)
- cracked seal to release electrolyte (internal resistance grows =>
capacity loss)
- cracked seal can suck moist air in => more corrosion
- uneven temperature conditions drive cell capacities and internal
resistance (5 Celsius average over 5 years is a big thing already)
- noticeable manufacturing defect (5% rejection rate at manufacturing, 0%
rejection rate in sales)
- developing manufacturing defect (raw material impurity, bad mixing, bad
storing, interrupted process,...)
- partial foil rupture at the pole assembly (sudden capacity loss)
- cells from different patches (you might have seen pictures from factories
how they pool cells all over the inspection floor and pick cells for
delivery)

There are so many things which can be done badly in the cell manufacturing.
It's unskilled workers or bad management or just mistakes. While it is not
hard to make cells it is hard to make good ones which serve 10-20 years.
And it is not very good idea to rely solely on Chinese QC even it has taken
giant leaps at most factories. In any product some defects land on users
garages. If it's not Li-ion cell it might be ignition switch on the car.

I believe one thing might help on this situation (why people are getting
away with it for so long): delay. As people buy cells and they arrive about
12 months after manufacturing (do not believe the date on the cell) they
still wait for some time before they get installed. Many do finalize the
formation on all cells by paralleling them and charging up to 4v region. So
I can see how some error mechanisms can be pushed down for a while.
Eventually the cells will die and one can just hope they die on same cycle
or 0v cell is found as it occurs (you can possibly feel the lack of power
in motor and the excess power at the cell internals).

I'm giving a presentation at annual insurance inspectors gathering about
battery fires and sample some investigations on devastating fire incidents.
BMS is one part of the equation.

 -Jukka
http://www.google.com/profiles/jarviju#about


2014-04-22 1:38 GMT+03:00 David Nelson <[hidden email]>:

> On Mon, Apr 21, 2014 at 9:45 AM, EVDL Administrator <[hidden email]>
> wrote:
> > On 21 Apr 2014 at 12:34, Michael Ross wrote:
> >
> >> I don't think bottom balancing is cult-ish. (It IS rude to talk bout it
> >> that way.) It is just complicated.
> >
> > I can see why you might think it rude.
> >
> > The term "cult" might be a bit strong.  But personally, I do see an an
> > element of a sort of "religion" in some of the bottom-balancing folk.
> Others
> > may not feel the same way.
>
> In all fairness, your statement can be equally applied to the "BMS
> only" crowd. As Michael and Damon point out, this is not as simple as
> one thing works and another thing doesn't. There are many parameters
> to consider in how a battery pack has been treated before anything can
> really be said about a particular method. I was fortunate enough to
> get 40 good cells. Now that I have 4 years and 18k miles on my pack
> and it is still going strong and is not getting out of balance with no
> balancing being done on any charge, you can see why I question the
> "requirement" of having a top balancing BMS whether it is active or
> passive. I purposely chose to go without the top balancing BMS I
> started out with because no one could show me the theoretical reason
> to have a top balancing BMS and I couldn't find one in all the
> researching I did either. For my climate and setup my data is still
> showing that a BMS is not necessary. Maybe if I lived where Jukka
> lives I would have different results. I know I'm not the only one with
> great results with no BMS. Blanket statements from either "camp" make
> them appear cultish.
>
> It may be that, as Jukka pointed out about the formation charges, I
> was actually fortunate to have very slowly (10A into 20 paralleled
> 100Ah cells) charged my cells to 4.00V initially and for a short time
> after installation. Now I charge to 3.455V/cell average. I don't
> charge if the case temp is at or below freezing, and I rarely
> discharge past 70%DOD.
>
> As for other types of lithium batteries besides LiFePO4, I can't say
> for sure, I haven't tested or researched them enough.
>
> --
> David D. Nelson
> http://evalbum.com/1328
> http://www.levforum.com
> _______________________________________________
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>
>
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