# [EVDL] figuire LFP life



## EVDL List (Jul 27, 2007)

There are a couple of things to consider in sizing your LFP pack.
Winston batteries (FKA ThunderSky) are rated to 3C current meaning 3
times the Ah rating of the battery. For example the WB-LYP40AHA
(http://www.thunder-sky.com/pdf/201072311158.pdf) is a 40Ah battery so
3C means that the current draw should be 3*40A=3D120A or less. You
should measure what your current draw is on acceleration to see if it
stays within spec otherwise the batteries will not last as long.

Second is the voltage of the string. My experience, using a CA, is
that using 3.2vpc (volts per cell) is a realistic nominal voltage to
use for calculations. Depending on the voltage limits of your
controller and DC-DC you could go with 22-23 cells in series. 22 cells
=3D 70.4V nominal, 23 =3D 73.6V nominal but the cells will sit at a higher
voltage than that with no load. The other thing to consider is the
ending charge voltage. I know the spec sheet says 4.00vpc but what it
doesn't tell you is that is while charging at 0.015C or 0.6A for a
40Ah pack. If your ending current is less than that your cutoff
voltage should also be lower. Furthermore, from my testing of cells on
the bench with low ending current there is very little energy above
3.45V. I recommend using a cutoff voltage of 3.5vpc or less. I'm using
3.485vpc with my pack and it has been doing just fine for the past
8000 miles. The higher your ending voltage the more stress you are
putting on the cells so why push it to the max? If you use 3.5vpc as
your ending voltage you will have to make sure your other electronics
can handle 22*3.5V=3D77V or 23*3.5V=3D80.5V. If you use a higher ending
voltage make sure you won't blow something out.

For useable energy capacity LiFePO4 cells are great because they are
nearly 100% efficient. So for a 22 cell pack of 40Ah cells the total
energy is 22*3.2vpc*40Ah=3D2816Wh. The most you should use is 80% of
this or 2252Wh. You should get the CA and measure your current energy
usage so you can plan your pack size for the range you need. You
didn't say what bike you have but I found one on evalbum.com which
claimed 83Wh/mi at 35mph. Suppose yours is this efficient. This would
mean you could go (2252Wh)/(83Wh/mi)=3D27miles before reaching 80%DOD.

You do need to invest in a properly programmed charger. When the
batteries reach full the voltage spikes really fast! You need a
charging system which can properly shut off. At the risk of starting a
war here you have a couple of options as far as a battery management
system. One method is to balance your cells once and then stay away
from the extreme ends of the charge curve. Charging to only 3.5V and
staying well above 80%DOD will work just fine with no cell level
monitoring. (NOTE: I am only referring the the LiFePO4 type of battery
here. This is an important point!) However, if you are not techie
enough to check your cells periodically you may want to look into the
various cell level monitoring options. The main thing is get educated
about the proper care of LiFePO4 batteries. I used to charge my cells
to 4.00vpc and balance them every time. What I learned from more
research and my own testing is that this is unnecessary and it harder
on the cells to charge to such a high voltage. In your search you will
find those who say you must have a BMS and balance each and every time
and you will find those at the opposite extreme who say a BMS will
damage your pack. So far my data and experience doesn't support either
extreme. I no longer balance my cells on charge but I haven't removed
my Black Sheep Technology BMS boards, either. I will say that unless I
get different data in the future my next conversion will not have cell
level monitoring but instead use a device which compares the voltages
of each half of my pack.

At this point no one knows how many years LiFePO4 batteries will last
in an automotive application. They haven't been around long enough.
Mine are from November 2009 but there are others who have been using
them for longer. Remember, however, in any statement about the life of
a cell the way the cell was used has a significant impact on
longevity.

HTH,

On Mon, Jun 13, 2011 at 11:49 AM, Peakfoto Digital Photo Still n Video


> <[email protected]> wrote:
> > I'm thinking for going to LFP form leadies . my leadies for motorcy=
> cle lasted 5000+ miles thanks to easy driving and parllel bank charger than=
> ks to the former owner!!
> ...


----------



## EVDL List (Jul 27, 2007)

Hi David,

I would be interested to hear what your theory is about why TS (WBL) 
still recommends taking their LYP's to 4.0V on charge...?

Regards, Martin Winlow
Herts, UK
http://www.evalbum.com/2092
www.winlow.co.uk




> David Nelson wrote:
> 
> > There are a couple of things to consider in sizing your LFP pack.
> > Winston batteries (FKA ThunderSky) ... Furthermore, from my testing
> ...


----------



## EVDL List (Jul 27, 2007)

Martin WINLOW wrote:

> I would be interested to hear what your theory is about why TS (WBL)
> still recommends taking their LYP's to 4.0V on charge...?

David, I would appreciate it if you could clarify just what you mean when you refer to charging with "low ending current".

A typical lithium profile is constant current to the target voltage, then hold that voltage until the current tapers to a suitably low level. Are you observing that if you use a lower target voltage, but then hold that voltage until the current tapers to a lower level, you achieve much the same state of charge/available capacity as if you were to use a higher target voltage but terminate the charge at a higher current level? If so, what difference have you observed by using the higher target voltage, but allowing the current to fall to the lower target level before terminating? 

Thanks,

Roger.

>


> David Nelson wrote:
> >
> > > There are a couple of things to consider in sizing your LFP pack.
> > > Winston batteries (FKA ThunderSky) ... Furthermore, from my testing
> ...


----------



## EVDL List (Jul 27, 2007)

Yttrium introduces a contaminate into the structure much like carbon is
introduced into iron to make steel. Iron is soft and not so strong but with
the introduction of a tiny amount of carbon the structure of iron now
becomes very strong and we call it steel. It is a deliberate contamination
of the parent substrate to change its properties. In the LiFePO substrate
yttrium is introduced in small amounts during manufacture and it strengthens
the structure in a way to allow a much slower break down and therefore
increase the life of the cell and maybe even increase the max voltage
allowed and decrease the internal resistance by keeping the structure open
better to allow a better exchange of ions. 

You get a lower internal resistance which allows a higher amp draw with
little to no degradation over time. 
A higher voltage limit though it really is not needed. 
Much longer cycle life. From 3000 cycles to 5000 cycles. Impressive. 

All that extra by adding in a tiny bit of yttrium. 

-----
If you don't understand, be patient, you will. Now I understand. 
--
View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/figuire-LFP-life-tp3594540p3599309.html
Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Thank you for that info, Chris. It explains what I'm seeing and why
CALB lists 3.4V as a "float voltage."

On Wed, Jun 15, 2011 at 9:33 AM, Christopher Darilek


> <[email protected]> wrote:
> > I've worked at a LiFePO4 manufacturer and with their cells they found tha=
> t 100%
> > charge could be achieved charging to 3.4V so long as the current tapers l=
> ...


----------



## EVDL List (Jul 27, 2007)

As an additional point on these LiFePO4 cells not having a self
discharge mechanism take a look at
http://media2.ev-tv.me/news061011-1280.mov (the file is 3.06 GB in
size). Starting at the 40min point it shows a new shipment of
WB-LYP400AHA cells being delivered to EVTV. Jack Rickard measures the
voltage on one and it reads 3.3076V. Next he opens a box which has
been sitting unopened since he got it. Inside are 4 cells which from
their size look like TS-LFP100AHA cells. The documentation in the box
state 2008 Oct 11 as the manufacture date. The film date is 2011 Jun
10. He takes a reading on each cell and gets the following: 3.3016V,
3.3020V, 3.2995V and 3.3021V.

If you have your cells and are not ready to install them in your car,
leave them alone!

-- 
David D. Nelson
http://evalbum.com/1328

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

> Lee Hart wrote:
> 
> > On 6/15/2011 10:08 PM, David Nelson wrote:
> > > As an additional point on these LiFePO4 cells not having a self
> ...


----------



## EVDL List (Jul 27, 2007)

> Gottdi wrote:
> 
> > Yttrium introduces a contaminate into the structure much like carbon is
> > introduced into iron to make steel.
> ...


----------



## EVDL List (Jul 27, 2007)

I had my conversion on blocks for some rewiring this past winter. It wasn't
driven from about November to early March. In about February, I got curious
about the battery state and got out my small charger to "top up" individual
banks of 5 cells. I put about 20 Ah into the cells. These are LFP100
cells, so they had lost about 20% in about 4 months.

Mike

> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Roger Stockton
> Sent: Wednesday, June 15, 2011 11:12 PM
> To: 'Electric Vehicle Discussion List'
> Subject: Re: [EVDL] figuire LFP life
> 


> > Lee Hart wrote:
> >
> > > On 6/15/2011 10:08 PM, David Nelson wrote:
> > > > As an additional point on these LiFePO4 cells not having a self
> ...


----------



## EVDL List (Jul 27, 2007)

> gottdi wrote:
> >
> > ..........and maybe even increase the max voltage allowed................
> >
> ...


----------



## EVDL List (Jul 27, 2007)

Message: 8
Date: Tue, 14 Jun 2011 18:54:45 -0700
From: David Nelson

>I'll try to articulate how I have reached my current position on
LiFePO4 charging and care.<

Your doing a good job of keeping data , I've wrote about the abused
100ah fox cells I got from a customers car and wonder if what I'm
seeing with this pack half of them are in Audrey's green bean and half
in my pick up., is what might happen to a pack after many cycles .
They don't stay balanced very long and run down on their own pretty
quick and do it to different degrees. I had separated 20 of the worst
one's out and had them sitting in front of the shop trying to breath
some life back into them. . Of the 20, 9 seemed to have some life,
( less than 40 amps, if that can be called "life". I hooked two
Anderson's plugs on them to make it easy to charge and discharge them
when I would charge one of my EV's ( I did this with a funny looking
3 set plug Anderson series plug that would put this test pack in
series with the charger so to discharge the test pack when charging
some EV. I have a e meter and timer, ( from an old close dryer max 80
min) on all this so to turn things off if I forget .This last month
has been a whirl wind of activity as we where getting ready to hit
the road . There are many people who have projects at my shop and even
though I've had little work all year , now everybody wants their
project done before we go ( explaining reason for careless behavior) .

As I'm passing these cells in and out of the shop I check them with
my meter .most I had given up on but I had 9 in 3 groups of 3 to make
a 12V battery ( they where all compressed together ) and one group
had fallen below 2v. the others where about 3.2. . So in a hurry I
decided to put a 12V car battery charger on them and pep them up for
a few hours before leaving . It was one of those shuemocker smart
chargers which are hard to keep going on a lead acid battery if it
isn't good . So when I saw 9v on the charger I though "It won't stay
on for long "and went back to work, till I was so tired that I forgot
and went home .

Next day back to work in the other shop and didn't notice the pile of
melted and burnt batteries in front of the green shed till noon.. So I
went to the house and told Audrey I has a little surprise in the shed
she should see and videoed this candid moment . I'll get her to post
the video. I wasn't going to write about it but hopefully others can
learn from my mistake. What made me put these batteries out side a
few months ago was hearing about the stories of the fire in someone
else's garage.

He is a little joke I told Audrey to make her feel better and make
her laugh....

" There once was an EV conversionist, who did a wonderful job on a
conversion, but had miswired the motor,
when the customer got in the car and put it in 1st gear, and hit the
GO peddle, he went flying in reverse into the back of the garage
causing heavy damage to the newly converted car. The conversionist,
realizing his mistake wandered off into the woods and spoke to GOD.
and GOD look down at this man crying out.. WHY??? WHY:??

And god looked down taking pity on him and said...
" my son, you have tried hard and done so with a good heart because of
this I am going to grant you one wish".
The poor feller, said IF ONLY we could have a battery that had
1000's of AMP hours and somehow would just charge itself on its own,
just by sitting, we would have Electric Cars everywhere.!

God took a deep breathe and said... I can't do that for many reasons,
..Not that it is not possible for ME to do this...but....first It
violates the laws of Physics,and second, I have many people working
on Battery Technology right now, there are great things to come in the
future if you will just be patient.

So God said, pick another wish.
So the man thought and replied..... " Well, how about just letting me
understand my mates moods. She can be so happy one minute and so sad
the the next. How one silly statement can up send her to the point of
tears......and then a few kind words can bring tears of joy.

God replies....... What Voltage did you want that Battery???


Steve Clunn


I

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Cell voltage at 2.2 volts for 8 months with no change has no self discharge
when the lead acid battery next to it has a significant voltage loss. The
2.2 voltage of the cell is at the knee of the discharge rate so if there is
a self discharge rate even at 1% we should see a significant voltage drop
across the pack of 38 cells if that is the size pack you have. 

So a cell at 2.2 volts that sits for 8 months and has a 3% self discharge
rate would be sitting at 1.672 volts. 

And if that same cell were only getting 1% self discharge then after 8
months of sitting it would equate to 2.024 volts. That is significant.
Multiply that by 38. 

2.2 volts each times 38 is 83.6 volts. 
After 8 months that would be 76.912 volts. 

That would be a 6.68 volt drop in 8 months time doing nothing. At 1% self
discharge. 

So you are saying that a cell will only self discharge to a certain point
then just stop self discharging? I thought you could self discharge all the
way to absolute zero. If there is voltage then there is something to
discharge. 

I am also going to assume you mean that as the self discharge voltage drops
the self discharge rate also decreases to a point that you really never
quite get to zero. 

Mmmmmmmm. 

I am not seeing that at all. 

Pete 

Remember that these are not Lead Acid. Don't assume they act like them. They
don't. 

-----
If you don't understand, be patient, you will. Now I understand. 
--
View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/figuire-LFP-life-tp3594540p3604151.html
Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

2011/6/15 Jukka J=E4rvinen <[email protected]>:
> Charging to 4V or ever higher helps to absorb the Li-Ions to places
> where they normally will not go.You'll be able to 'format' the cell
> afterwards. Expensive and coherent particle structures have the effect
> too but it's quite mild.

Isn't this done at the factory with the first capacity test? I
understand that they capacity test the cell and then take it to
~50%SOC before shipment.

> TS cells have been proven (believe or not) to work better if charged
> high every now and then. Keeping the cells at high voltages for longer
> time will murder the electrolyte. It dissolves. How long time you keep
> the cell at high voltage and/or temperature hastens the degration.

How often is "every now and then?" I would think this would depend on
some Ah delivered by the cell figure. Also, by "work better" do you
mean they output power better, have higher capacity, or have a longer
cycle and/or calendar life?


> How to do it 'right':
>
> Charge the cells and voltage balance to 3,85 V. Then take the whole
> pack up to 4,0-4,25 for few minutes. After getting all cells to the
> top check the measured As (Ah/3600) between 3,85 and 4,25 per cell.
> This will help you to know how to balance while operating at the
> 'flat' which Lee reminded us.

Is there data on only charging to ~3.5vpc to compare this to? I
haven't seen any. Maybe it isn't available yet. How do you know that
the method you outlined is the "right" method? I wasn't able to find
the data on your site last time I looked but it has been a few months
so maybe it is there now.

> Now .. in general.. staring the voltages is pretty much meaningless if
> you do not know the cell properties. Long life of the LiFePO4 is
> forgiving and many get away for many years without BMS. But
> eventually.. someday... it will not be enough anymore. Cells will
> float apart and pack will be unmanageable. Change on cell and do it
> one by one... fine.. what ever suits you best.

The question I have is this. When the cells become "unmanageable" is
this also the end of life of the pack where it would be replaced any
way? Maybe a half-pack voltage comparison monitor is all that would be
needed.

> Ever driven your EV 100.000 miles ? Just driving not 'hobbying' ? This
> is what I'm talking about. Not arguing if anyone should sit on the
> cells every time they're charged.

If I could have done the conversion I wanted then I be at 40k mile by
now but no, I'm only at ~8000 miles in the last 18 months. My pack is
very young in the cycle life department. It is at ~90 cycles
equivalent looking at delivered Ah.

> Personally.. I will never 'go back' to that with a daily driver.

Are you saying you will never go back to manually monitoring cells on
a daily driver? That you will have some sort of automated monitoring
and balancing system?

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

Thank you for your input. I hope I'm not sounding like I'm attacking.
I really want to know but it is difficult to sort through the "believe
me because I said so" stuff from the statements backed by data.
Furthermore, there are so many variables in how LiFePO4 batteries are
charged and used it is difficult to sort out what factors caused the
results.

-- =

David D. Nelson
http://evalbum.com/1328

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Mike,

Were the cells hooked up to anything or were they completely
disconnected? No BMS, no other parasitic loads in the vehicle. Are
these TS or CALB cells or some other brand? The quality of the cell
looks like it makes a difference, too.

On Wed, Jun 15, 2011 at 10:51 PM, Mike Nickerson


> <[email protected]> wrote:
> > I had my conversion on blocks for some rewiring this past winter. It w=
> asn't
> > driven from about November to early March. In about February, I got cu=
> ...


----------



## EVDL List (Jul 27, 2007)

> Gottdi wrote:
> 
> > Remember that these are not Lead Acid. Don't assume they act like them.
> > They don't.
> ...


----------



## EVDL List (Jul 27, 2007)

Steve, Thank you for posting. If everyone would post about their
mistakes we would all have an opportunity to learn faster.
Unfortunately, some who I assume have a low self esteem, would rather
call the mistake makers an idiot rather than see the opportunity they
were given.

FWIW, I don't think in your situation a BMS would have helped unless
it was set to cut power to the charger to turn it off. This does show,
however, what can happen when these cells are overcharged. There is a
possibility that some of the EV fires of late were due to overcharging
the cells and is one of the reasons I think undercharging them is a
safer route to go.

In case others missed the video link in the other email here is
Steve's video of the event:
http://www.youtube.com/watch?v=3DegE0VbNabQ0




> Steve Clunn <[email protected]> wrote:
> [...]>
> > Next day back to work in the other shop and didn't notice the pile of
> > melted and burnt batteries in front of the green shed till noon.. So I
> ...


----------



## EVDL List (Jul 27, 2007)

The cells were still wired into the car, but the main disconnect was open.
They are TS cells. Each cell has a miniBMS module on top.

Mike

> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of David Nelson
> Sent: Thursday, June 16, 2011 9:22 PM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] figuire LFP life
> =

> Mike,
> =

> Were the cells hooked up to anything or were they completely
> disconnected? No BMS, no other parasitic loads in the vehicle. Are these
TS
> or CALB cells or some other brand? The quality of the cell looks like it
makes a
> difference, too.
> =

> On Wed, Jun 15, 2011 at 10:51 PM, Mike Nickerson


> > <[email protected]> wrote:
> > > I had my conversion on blocks for some rewiring this past winter. It
> > > wasn't driven from about November to early March. In about February,
> > > I got curious about the battery state and got out my small charger to
> ...


----------



## EVDL List (Jul 27, 2007)

Mike,

The MiniBMS modules use 7mA - all day, every day : 24 hours x 30 days 
x 5 months = 25Ah!

MW




> Mike Nickerson wrote:
> 
> > The cells were still wired into the car, but the main disconnect was
> > open.
> ...


----------



## EVDL List (Jul 27, 2007)

> Lee Hart <[email protected]> wrote:
> > On 6/16/2011 7:59 PM, gottdi wrote:
> >> Cell voltage at 2.2 volts for 8 months with no change has no self discharge
> >> when the lead acid battery next to it has a significant voltage loss.
> ...


----------



## EVDL List (Jul 27, 2007)

> Lee Hart wrote:
> >> With lead-acid, voltage is an indicator of state of charge.
> >> With lithiums, voltage is *NOT* an indicator of state of charge.
> 
> ...


----------



## EVDL List (Jul 27, 2007)

Lee 

You said

For lead-acid, voltage is fundamentally related to state of charge. One 
of the two reactants (the sulfuric acid) changes concentration with 
state of charge, and the concentration affects the voltage and internal 
resistance.

The effect is small; there's less than a 10% change in voltage over the 
useful range from 20% to 80% SOC. The change with SOC is also smaller 
than that caused by other effects, such as current, recent 
charge/discharge history, age, etc.

Thus voltage is a weak indicator of SOC. It is not very trustworthy; but 
we often use it anyway because it's easy.

For lithiums, the two reactants do *not* change concentration with state 
of charge. So there is no fundamental change in voltage as a function of 
SOC. The voltage only changes when it finally runs out of reactants near 
0% or 100% SOC.

The voltage also changes from many secondary effects; the exact 
chemistry used, current, recent charge/discharge history, temperature, 
age, etc.

This means that voltage is a *very* weak indicator of SOC for lithiums 
over the normal range of 20-80% SOC. It's like trying to forecast the 
weather by grandma's arthritis; there may be a relationship, but it's so 
weak as to be unreliable.

OK now for question
Got to wondering if the electrolyte in a lithium changes concentration or IF there is another chemical effect(?) in electrolyte that changes.
IF so then it is theoretically possible to use this as guage of charge as done with lead acid and gravity.

Finding and or designing a detector is another issue that will depend on thorough understanding of the chemical reactions.

I do not pretend to know much about Li chemistry - just that the electrolyte is an organic solvent based system. So I have some heavy reading to do.
Can you refer to good sources of literature please?

Thanks
Dan Bentler 

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

"For lithiums, the two reactants do *not* change concentration with state
of charge. So there is no fundamental change in voltage as a function of
SOC. The voltage only changes when it finally runs out of reactants near
0% or 100% SOC."

The voltage does steadily change with SOC during charging in the 20% to 80%
SOC range, just not exponentially like it does near the ends of
charge/discharge (from data logs of voltage versus time using cell log8). 
It also changes with discharge. To me the main reason it isn't useful as a
gauge of SOC is that it fluctuates all over the place depending on discharge
current and is never repeatable. The only repeatable voltage measurement
I've found is to let cells "rest" for at least 3 hours before measuring
voltage. This seems to give repeatable results over a wide range of SOC
(based on checking against TBS gauge), but is hardly useful for a real time
indicator of SOC. I think once you are calibrated, you can get a ballpark
idea of SOC by checking voltage under a specific discharge current like 100
or 200A, but it is a very rough estimate, so of limited use. I expect it is
also a function of temperature but haven't checked.



--
View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/figuire-LFP-life-tp3594540p3608535.html
Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

It is so much simpler to count in and out the Ahs. And they are very
very accurately reporting the SOC. It's not even expensive nowadays.
Simple and cheap logic can do the task.

If you discharge the say TS-type cell with various rates you should
take a reference of the 80% SOC voltage at all rates. Then compare it
to the voltage, temperature, age and current (R:int). And you got a
mess with high calculation requirements and deep understanding about
the cell type.

-akkuJukka


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



2011/6/19 tomw <[email protected]>:
> "For lithiums, the two reactants do *not* change concentration with state
> of charge. So there is no fundamental change in voltage as a function of
> SOC. The voltage only changes when it finally runs out of reactants near
> 0% or 100% SOC."
>
> The voltage does steadily change with SOC during charging in the 20% to 8=
0%
> SOC range, just not exponentially like it does near the ends of
> charge/discharge (from data logs of voltage versus time using cell log8).
> It also changes with discharge. To me the main reason it isn't useful =
as a
> gauge of SOC is that it fluctuates all over the place depending on discha=
rge
> current and is never repeatable. The only repeatable voltage measureme=
nt
> I've found is to let cells "rest" for at least 3 hours before measuring
> voltage. This seems to give repeatable results over a wide range of SOC
> (based on checking against TBS gauge), but is hardly useful for a real ti=
me
> indicator of SOC. I think once you are calibrated, you can get a ballp=
ark
> idea of SOC by checking voltage under a specific discharge current like 1=
00
> or 200A, but it is a very rough estimate, so of limited use. I expect =
it is
> also a function of temperature but haven't checked.
>
>
>
> --
> View this message in context: http://electric-vehicle-discussion-list.413=
529.n4.nabble.com/figuire-LFP-life-tp3594540p3608535.html
> Sent from the Electric Vehicle Discussion List mailing list archive at Na=
bble.com.
>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere. Thanks.
> |
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev
>

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

2011/6/18 Jukka J=E4rvinen <[email protected]>:
> It is so much simpler to count in and out the Ahs. And they are very
> very accurately reporting the SOC. It's not even expensive nowadays.
> Simple and cheap logic can do the task.

We aren't talking about an SOC meter for an EV or how to measure SOC
during use. The question is, can the SOC of a LiFePO4 cell be
determined using only voltage given that the cell has been sitting
with no charge/discharge for an extended period of time? Jack Rickard
measured the voltage of some TS cells which had sat for 2 years 8
months and compared them to a brand new cell just arrived from China.
He used an Agilant (sp?) meter which displayed to the ten-thousandth
place. While this is difficult to use in an EV application and the
middle 80-20%SOC range of the cells has a flat voltage curve does it
actually have a zero slope? Note that flat doesn't mean it isn't
tilted. That is the question. If voltage can be used for SOC
measurement of a LiFePO4 cell then what JR's measurement shows is that
there is little, if any, self discharge in these cells. Assuming, of
course, that the cells were all at exactly the same SOC when they left
the factory. It could be, however that the difference between the new
cell of 3.3076V and the lowest old cell of 3.2995V (0.0081V) is
significant in terms of SOC.



-- =

David D. Nelson
http://evalbum.com/1328

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

> Lee Hart <[email protected]> wrote:
> > Lee Hart wrote:
> >>> With lead-acid, voltage is an indicator of state of charge.
> >>> With lithiums, voltage is *NOT* an indicator of state of charge.
> ...


----------



## EVDL List (Jul 27, 2007)
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----------



## EVDL List (Jul 27, 2007)
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----------



## EVDL List (Jul 27, 2007)

When I first put my car on the road I did not have an amp hour counter and
drove around using pack voltage. From fully charged resting around 122V for
my 36 CALB cells to 108V allowed me to safely use most of my pack capacity
on a regular basis. 114V was my "better be getting near a plug voltage". I
only had to creep home once, but only because I wasn't paying attention to
what my voltmeter was clearly showing. The voltage curve is not really flat
even in the middle, though certainly not as pronounced as the ends.




> Lee Hart wrote:
> >
> > On 6/16/2011 7:59 PM, gottdi wrote:
> >> Cell voltage at 2.2 volts for 8 months with no change has no self
> ...


----------



## EVDL List (Jul 27, 2007)
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=


----------

