Re: TS chemistry Was A123 chem

Re: TS chemistry Was A123 chem

Here's some cycling data for all of you on list.

Test subject is TS LFP-30 cell. 1st patch ever made.

1600th cycle just got this morning and still holding 69% of the original
capacity.

Now .. All cycles are 1C (from original capacity) charge and discharge.

Discharged to 2V and charged to 4,30V on each cycle.

So 100% what can be taken out in any condition.. I would say.

How's that for the cheapo Chinese stuff.. ??

I'll have the internal resistance numbers coming up later so that might
affect on the 69% somewhat.

-Jukka


Rich Rudman kirjoitti:
> I have 4 of the TS-LFP40aha on cycle life testing.
>
> So far very good results.
> I am trying to hold them to the %70 DOD spec that yields a 3000 cycle life
> curve.
>
> I have Mk3Lion Regs on each cell. I have the top set to 4.01 volts and the
> floor I ran 20 cycles with a floor of 2.5 volts. The yielded about %98 DOD
> on all 20 cycles.
> Damn!! Those cells sure make cheap lead acid look like junk!!
>
> I am now runnig with a floor of 2.80 volts per cell. I hope to restrict the
> Ahrs to aproximateley 32. This is the %80 DOD point, When these cycles are
> run, Then I am upping the voltage floor to 3.00 volts and hoping the results
> will be 28 amp hours, Then I am going to run them for ever!
> I expect that by the time I get to cycle 2000 the added shop heat will be a
> welcome addition to the heating budget at the Power shop. Right now .. it's
> a crime to be making any heat in hot shop in August. Doing PFC40 liquid
> coole chargers.. on a 80 Deg day, Well that wasted heat is not doing anybody
> any good.
>
> The set up is 4 cells in series, for a 12 volt..aka 16 volt pack, I have 4
> modified MK3 Digi regs doing data collection, and Reg/charger feed back for
> the high and low Gard voltage feature. The Cycles.. is a 50 amp class
> charger set up as a Windloader, and a PFC30 Hanger Queen doing 30 amps of
> charge power....Cute pile of equipment, finally earning it's keep.
>
> The Regs do dissapate and equalize the cells when they Reg at 4.01 volts,
> This keep the pack equalized on every charge off state. The cycler is
> programmed to hold peak volts of 16.00 until the amps taper to 5 amps on the
> charge side. And.. the regs hold any one cell in line as well as the
> charger.
> On discharge I cancell the draw down at the set floor voltage of 2.81 and
> when the current drops below 10 amps. So we do get a charge taper and a
> discharge taper.
>
> Works for Me.
> Any Questions?
>
> Rich Rudman
> [email protected]
> Manzanita Micro
> 360-297-7383,
> Cell 360-620-6266
> Production shop 360-297-1660
> FAX at Metal shop 1-360-297-3311
>
>
>
>
> ----- Original Message -----
> From: "Sam Maynard" <[email protected]>
> To: <[email protected]>
> Sent: Sunday, July 29, 2007 6:29 PM
> Subject: RE: A123 chemistry
>
>
>> The ideal charge profile for the TS LiFePO4 chemistry is constant
>> current of .3C to 80% SOC, then constant 4.2V to full, according to TS.
>>
>> I took delivery (Well, it wasn't exactly delivery, the air shipping
>> agents were a PITA - reverse engineer the acronym) of some 40Ah and 90Ah
>> LFP cells, and was impressed that the relaxed voltage was 3.31V for each
>> of 45 cells on arrival, no deviation to the 2nd decimal place. I was
>> looking to manifest a parallel "float level maintainer" (to buy storage
>> time until BMS) when I measured each cell again 10 days later. Still
>> 3.31V for each one after 10 days, although TS says self discharge is
>> about 5% per month (or is that .5% ?).
>>
>> Although that is a relief, I know I have to come up with a safe parallel
>> storage charger soon, and better yet, BMS/charge so they can be put on
>> some 2-wheelers.
>>
>> Anyone who has already blazed this trail, advice appreciated (thanks
>> Jukka-I'm sure you have your hands full too). Otherwise, I'll see what
>> I can come up with and let you know how it works.
>>
>> -S
>>
>> -------- Original Message -------
>> Subject: RE: A123 chemistryrool
>> From: Jeff Shanab <[email protected]>
>> Date: Fri, July 27, 2007 8:38 pm
>> To: Electric Vehicle Discussion List <[email protected]>
>>
>> I had talked with them early, when they would talk to us normal people.
>> and Since then,via email, to the factory in china that claims to make
>> the cells for them until they get their own plant going and in boththis
>> conversations they have said Lithium-Iron-Phosphate.
>>
>> But it is easier than this to check. Get out your voltmeter.
>>
>> Lithium cobalt 3.6Vnominal 4.25Max charge
>> Lithium Iron Phosphate 3.2-3.4 3.7 max charge (Easy to tell)
>> Lithium-magenese 3.7-3.8 Nominal 4.2Max charge (ok, hard to tell
>> compared to cobalt)
>>
>> http://www.batteryuniversity.com/partone-5A.htm
>>
>>
>>
>
>

--
Jukka Järvinen
R&D Director
Oy Finnish Electric Vehicle Technologies Ltd
Teollisuuskatu 24 A3
11100 RIIHIMÄKI

jukka.jarvinen(at)fevt.com
cell phone +358-440-735705
wired phone +358-19-735705
fax +358-19-735785

Re: TS chemistry Was A123 chem

Oh.. I forgto to ask...

Rich.. have you measured the over all efficiency with the clampers and
balancing ?

From outlet to motor (or what ever load)

We made such clamping devices with Victor but I had hard time to
convince me that this is the route. It was WAY too wasty.

But.. of couse it works ok. It does the trick and you can have the Lion
in the tank...

Balancing by rerouting the energy around the pack is how we are doing it
every day now. We get over 90% out what we put in. With balance.

No balancing sequences in the low and high end of SOC.

After you get more cycles in the pack measure the differences on the
cells and discover how they have evolved.

Any case .. These small cells beat the SLAs in efficiency and cycle
life. So the absolute maximum is not perhaps required. To triple the
lifetime and usability in a car already "pays back" nicely.

I try to come to PIR at 18th. Hope to see some of you there. I tried
already to get to invitational but timing was bad.

-Jukka


Jukka Järvinen kirjoitti:
> Here's some cycling data for all of you on list.
>
> Test subject is TS LFP-30 cell. 1st patch ever made.
>
> 1600th cycle just got this morning and still holding 69% of the original
> capacity.
>
> Now .. All cycles are 1C (from original capacity) charge and discharge.
>
> Discharged to 2V and charged to 4,30V on each cycle.
>
> So 100% what can be taken out in any condition.. I would say.
>
> How's that for the cheapo Chinese stuff.. ??
>
> I'll have the internal resistance numbers coming up later so that might
> affect on the 69% somewhat.
>
> -Jukka
>
>
> Rich Rudman kirjoitti:
>> I have 4 of the TS-LFP40aha on cycle life testing.
>>
>> So far very good results.
>> I am trying to hold them to the %70 DOD spec that yields a 3000 cycle
>> life
>> curve.
>>
>> I have Mk3Lion Regs on each cell. I have the top set to 4.01 volts and
>> the
>> floor I ran 20 cycles with a floor of 2.5 volts. The yielded about %98
>> DOD
>> on all 20 cycles.
>> Damn!! Those cells sure make cheap lead acid look like junk!!
>>
>> I am now runnig with a floor of 2.80 volts per cell. I hope to
>> restrict the
>> Ahrs to aproximateley 32. This is the %80 DOD point, When these cycles
>> are
>> run, Then I am upping the voltage floor to 3.00 volts and hoping the
>> results
>> will be 28 amp hours, Then I am going to run them for ever!
>> I expect that by the time I get to cycle 2000 the added shop heat will
>> be a
>> welcome addition to the heating budget at the Power shop. Right now ..
>> it's
>> a crime to be making any heat in hot shop in August. Doing PFC40 liquid
>> coole chargers.. on a 80 Deg day, Well that wasted heat is not doing
>> anybody
>> any good.
>>
>> The set up is 4 cells in series, for a 12 volt..aka 16 volt pack, I
>> have 4
>> modified MK3 Digi regs doing data collection, and Reg/charger feed
>> back for
>> the high and low Gard voltage feature. The Cycles.. is a 50 amp class
>> charger set up as a Windloader, and a PFC30 Hanger Queen doing 30 amps of
>> charge power....Cute pile of equipment, finally earning it's keep.
>>
>> The Regs do dissapate and equalize the cells when they Reg at 4.01 volts,
>> This keep the pack equalized on every charge off state. The cycler is
>> programmed to hold peak volts of 16.00 until the amps taper to 5 amps
>> on the
>> charge side. And.. the regs hold any one cell in line as well as the
>> charger.
>> On discharge I cancell the draw down at the set floor voltage of 2.81 and
>> when the current drops below 10 amps. So we do get a charge taper and a
>> discharge taper.
>>
>> Works for Me.
>> Any Questions?
>>
>> Rich Rudman
>> [email protected]
>> Manzanita Micro
>> 360-297-7383,
>> Cell 360-620-6266
>> Production shop 360-297-1660
>> FAX at Metal shop 1-360-297-3311
>>
>>
>>
>>
>> ----- Original Message ----- From: "Sam Maynard" <[email protected]>
>> To: <[email protected]>
>> Sent: Sunday, July 29, 2007 6:29 PM
>> Subject: RE: A123 chemistry
>>
>>
>>> The ideal charge profile for the TS LiFePO4 chemistry is constant
>>> current of .3C to 80% SOC, then constant 4.2V to full, according to TS.
>>>
>>> I took delivery (Well, it wasn't exactly delivery, the air shipping
>>> agents were a PITA - reverse engineer the acronym) of some 40Ah and 90Ah
>>> LFP cells, and was impressed that the relaxed voltage was 3.31V for each
>>> of 45 cells on arrival, no deviation to the 2nd decimal place. I was
>>> looking to manifest a parallel "float level maintainer" (to buy storage
>>> time until BMS) when I measured each cell again 10 days later. Still
>>> 3.31V for each one after 10 days, although TS says self discharge is
>>> about 5% per month (or is that .5% ?).
>>>
>>> Although that is a relief, I know I have to come up with a safe parallel
>>> storage charger soon, and better yet, BMS/charge so they can be put on
>>> some 2-wheelers.
>>>
>>> Anyone who has already blazed this trail, advice appreciated (thanks
>>> Jukka-I'm sure you have your hands full too). Otherwise, I'll see what
>>> I can come up with and let you know how it works.
>>>
>>> -S
>>>
>>> -------- Original Message -------
>>> Subject: RE: A123 chemistryrool
>>> From: Jeff Shanab <[email protected]>
>>> Date: Fri, July 27, 2007 8:38 pm
>>> To: Electric Vehicle Discussion List <[email protected]>
>>>
>>> I had talked with them early, when they would talk to us normal people.
>>> and Since then,via email, to the factory in china that claims to make
>>> the cells for them until they get their own plant going and in boththis
>>> conversations they have said Lithium-Iron-Phosphate.
>>>
>>> But it is easier than this to check. Get out your voltmeter.
>>>
>>> Lithium cobalt 3.6Vnominal 4.25Max charge
>>> Lithium Iron Phosphate 3.2-3.4 3.7 max charge (Easy to tell)
>>> Lithium-magenese 3.7-3.8 Nominal 4.2Max charge (ok, hard to tell
>>> compared to cobalt)
>>>
>>> http://www.batteryuniversity.com/partone-5A.htm
>>>
>>>
>>>
>>
>>
>

--
Jukka Järvinen
R&D Director
Oy Finnish Electric Vehicle Technologies Ltd
Teollisuuskatu 24 A3
11100 RIIHIMÄKI

jukka.jarvinen(at)fevt.com
cell phone +358-440-735705
wired phone +358-19-735705
fax +358-19-735785