EV Digest 5797
Topics covered in this issue include:
1) Re: Apple recalls 1.8 million laptop batteries / A123 battery fire
by =?ISO-8859-1?Q?Jukka_J=E4rvinen?= <[EMAIL PROTECTED]>
2) RE: Apple recalls 1.8 million laptop batteries / A123 battery fire
by "Don Cameron" <[EMAIL PROTECTED]>
3) RE: Freedom EV Crash Test?
by Jeff Shanab <[EMAIL PROTECTED]>
4) Re: Potbox alternative
by Jeff Shanab <[EMAIL PROTECTED]>
5) Re: What's faster? 2, 9's, 11's, or 13's?
by "Ryan Stotts" <[EMAIL PROTECTED]>
6) Re: Potbox alternative
by "Stefan T. Peters" <[EMAIL PROTECTED]>
7) Re: Electric sport car from Quebec
by "ROBERT GOUDREAU" <[EMAIL PROTECTED]>
8) Re: corroding wires - *inside* the insulation!?
by Lee Hart <[EMAIL PROTECTED]>
9) Re: A note on potentiometers
by Lee Hart <[EMAIL PROTECTED]>
10) Re: Storing batteries dry, was:Re: Charles Whalen, WKTEC, and filet mignon
by "Charles Whalen" <[EMAIL PROTECTED]>
11) Re: Apple recalls 1.8 million laptop batteries / A123 battery fire
by =?ISO-8859-1?Q?Jukka_J=E4rvinen?= <[EMAIL PROTECTED]>
12) RE: World's First Electric Junior Dragster
by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
13) Re: Potbox alternative
by Danny Miller <[EMAIL PROTECTED]>
--- Begin Message ---
This will not perhaps apply on all brands.. but FYI.
Large Li-Co cell packs can be put down with water. It will lower the
tempereature nicely and prevent any further cell failures.
With bad design it is possible to get the domino effect and burn the
whole pack. I other words: make it too tight pack.
One tested setup:
15 pcs of 200 Ah Li-Co (ThunderSky brand) cells in one tightly packed
string. Overcharge (5V reached) applied to one cell in the middle.
Emergency vent wokred after few minutes as supposed and some gasses
coming out with high pressure. Lots of white/grey smoke. After about ten
minutes first flames. Heavy copper bus bars (150 mm2) are hot. They
wokred as heatsinks and transferred the heat from the destroyed cell to
next cells and surrounding air.
At this point we applied water. Batteries were in a box with sides
higher than cells. Water was about 10 celsius before applying. Water
added (100 litres) and cells are fully immersed. Show was over. Cells
removed from the box next day and rest of the cells are ok. Both cells
in the next to the metled cell have melted to one 3 cell block. Both
side cells have over 4 V as supposed.
Some of the cells from this test are still in use. Test was done in 2004.
During other similar test I inhaled massive amounts of the this white
smoke.(ALL FOR SCIENCE!). Not very intentionally thou. After complete
tests and blood analysis nothing implying of a poisoning was found. No
other effect on the test person but he is a complete Lithium head
nowadays :)
I have 350 Ah LiFeP cells to be penetration tested soon. Overcharge
tests were done with 150 Ah LiFeP cells and they did not even heat in
over 5V/cell. They got a dent in capacity and performance but no fires
or any other visually noticeable changes.
I have been next to such cell with overcharge situation (I personally
was not conducting the test). Cell voltage was 10.11V ! No effect which
would been possible to see from outside.
Personally I'm slowly dumping all Li-Co cells. They will be replaced
with Li-Fe cells. A bit less (20%) energy in same weight but the safety
factor is a multiplier in this case...
BMS is required not because of safety but for usability and long
lifetime. This is why I really hate the usage of BMS on any protection
circuitry you can get your hands on (99% of all "BMS" existing today are
such).
-Jukka
fevt.com
Michael Perry kirjoitti:
http://www.allelectronics.com/battery_safety.html says to only charge
Lithium batts in a fireproof container. Never leave unattended. It's very
dangerous to breathe the fumes and all that is required is for lithium to be
exposed to air. That might explain a singe ruptured cell taking out the
entire cargo. In an accident, it recommends removing yourself quickly and
staying away for at least half an hour.
http://www.findarticles.com/p/articles/mi_m0UBT/is_29_18/ai_n6280927 says
for small fires, Lith-x or Halon will work. For lager fires they say to
remove yourself and apply *lots* of water from a long range. (Remember, the
fumes are hazardous.)
----- Original Message -----
From: "Danny Miller" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, August 25, 2006 1:41 PM
Subject: Re: Apple recalls 1.8 million laptop batteries / A123 battery fire
Any idea how a lithium battery fire would be extinguished?
Will exposed lithium would burn violently when mixed with water (like
sodium), or does this not occur with the lithium compounds used?
There are several different classes of fire extinguisher, which one is
most appropriate? Are there types that would actually make the fire
worse?
Danny
Charles Whalen wrote:
Thanks Roger and Ed for explaining how these fires in cylindrical li-ion
cells are usually the result of internal shorts caused by tiny metal
particle contamination across the separator as an occasional but
inevitable
imperfection of the manufacturing process (which I assume must be
difficult
to nearly impossible to completely eliminate through standard and even
enhanced quality control testing techniques -- if Sony can't do it, then
surely nobody can, as Ed suggested).
Combining this with Bill Dube's explanation of the mechanics of how
such a
fire would burn in an A123 (LiFeP) 26650 cell in response to my previous
post asking about Craig Uyeda's A123 cell fire, I would guess that
this type
of occasional but inevitable manufacturing imperfection that you guys
described is probably what caused the fire (due to just such an internal
short) in that single one of Uyeda's A123 cells (out of a pack of 100
cells), which burned up the "thimble-full of liquid electrolyte" in the
cell, but not having any oxides within the cell to further fuel the
fire (as
is the case in the common LiCoO2 18650 industry-standard laptop
cells), the
fire burned itself out fairly quickly such that it was contained to that
single cell and didn't spread in a chain reaction to the other 99
cells in
the pack, as almost always seems to be the case with assembled packs of
LiCoO2 18650 laptop cells.
Yeah, you're right that even the best, most sophisticated, most highly
engineered BMS in the world with triple and quadruple redundant
fail-safe
backups is useless and can't do anything to prevent this sort of
conflagration of LiCoO2 18650 laptop cells (caused by such an internal
short
within a single cell), but at least with A123 LiFeP 26650 cells, any
such
fire is likely to be of short duration, contained to the single cell,
and
won't erupt into a conflagration of the pack, as Bill Dube' explained.
This leads to another question or two. I've heard that A123 is
working on
the development of large-format, EV-size cells in the 100-200Ah range.
First, I wonder what their timetable is on that, at least for having
prototype cells available. Second, I wonder if the much larger format
cell
and its manufacturing process (as distinct from that of a small cell) is
inherently more amenable to solving/preventing this sort of
manufacturing
imperfection in the small cells where this type of tiny metal particle
contamination occasionally occurs. Anyone have any insight into
either of
those two questions?
Very interesting.
Charles Whalen
On Thursday, August 24, 2006 7:20 PM, Roger Stockton wrote:
Edward Ang wrote:
Dell confirmed that the problem is manufacturing
contamination. Metal particles remained in the
cell causing shorts across the separator.
The problem is inside the cell, so, no amount of
BMS could prevent the problem.
The cells are made by Sony. Makes you wonder if
Sony (the inventor of LiIon batteries) and one of the
best consumer product manufacturers could not nail
the manufacturing process, who else could, doesn't it?
I wonder what impact would these recalls have on Tesla
and AC Propulsion since they both actively advertise their
systems use laptop computer LiIon batteries.
This is one of the main reasons AIR Lab decided to focus
on the robust Nimh battery. The last thing we need is an
EV that burst into flame on the freeway. The local and
national news would love to cover and exaggerate this.
--
Edward Ang
President
AIR Lab Corp
I wrote about this precise problem with the LiIon cylindrical cells
upon
my return from the 2006 Advancements in Battery Technology & Power
Management conference in April.
It appears *inevitable* that there will be failures of this sort
regardless of the manufacturer, although the frequency/likelihood is
dramatically higher with less well-controlled manufacturing processes
such as are often associated with lower-cost Chinese production.
The safer cell chemistries may contain the damage to the single
defective cell rather than proceeding into an uncontrolled combustion
of
neighbouring cells as well, but the issue seems to remain that the
cyclindrical cells are prone to this sort of internal shorting, and
there is nothing an external BMS can do about it.
Cheers,
Roger.
On Wednesday, August 23, 2006 5:58 PM, Bill Dube wrote:
The electrolyte is an organic solvent. There is a thimble
full in each cell. If you short a cell, it can overheat and vent the
solvent. If there is an ignition source present (like the red-hot
shorted interconnect) you can get a flame. Once the solvent is gone,
or you starve the fire for oxygen, the flame goes out. You won't get
much flame in a closed battery box, for example, because you will
quickly use up the oxygen.
This is distinctly different to what other types of Li-Ion
cells do. In those type cells fire is internal. These traditional
style of Li-Ion cell behave just like a road flare or a roman candle.
You can't put them out. They require no air to continue burning. The
whole pack is going to burn and there is nothing you can do but watch
(perhaps roast a marshmallow.)
Quite a big difference.
Bill Dube'
At 02:07 PM 8/23/2006, Charles Whalen wrote:
That guy Craig Uyeda claims that one of his 100 A123 li-ion cells
caught
on fire. Does anyone know the circumstances of that and how it
happened?
I didn't think it was possible for A123 li-ions to catch fire
because of
their lithium-iron-phosphate chemistry being very distinct and much
safer
than the common lithium-cobalt-oxide chemistry used in the
industry-standard 18650 laptop cells, in particular with no "oxide"
to be
liberated in the case of LiFeP. Valence and A123, both of which use
lithium-iron-phosphate chemistries, claim that something like that (a
fire) is not supposed to be able to happen with their batteries.
Very curious and wondering how that happened with the A123 cell.
Charles Whalen
On Wednesday, August 23, 2006 9:00 AM, Mark Fisher wrote:
This thread
http://www.visforvoltage.com/forums/index.php?act=ST&f=31&t=4325&s=71612a004543b13cb5673077c0e2711a
has some discussion of the effects of lithium fires. Craig Ucheda is
a
particularly extreme EV scooter enthusiast. Apparently the Fire
Marshall
isn't so thrilled by his hobby...
Of course, gasoline burns pretty well too...
http://www.youtube.com/watch?v=rdCsbZf1_Ng&NR
Mark
--- End Message ---
--- Begin Message ---
Hi Jukka, what brand of Li-Fe cells are you planning on using?
Don Cameron, Victoria, BC, Canada
see the New Beetle EV project www.cameronsoftware.com/ev
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Jukka Järvinen
Sent: August 26, 2006 7:58 AM
To: [email protected]
Subject: Re: Apple recalls 1.8 million laptop batteries / A123 battery fire
This will not perhaps apply on all brands.. but FYI.
Large Li-Co cell packs can be put down with water. It will lower the
tempereature nicely and prevent any further cell failures.
With bad design it is possible to get the domino effect and burn the whole
pack. I other words: make it too tight pack.
One tested setup:
15 pcs of 200 Ah Li-Co (ThunderSky brand) cells in one tightly packed
string. Overcharge (5V reached) applied to one cell in the middle.
Emergency vent wokred after few minutes as supposed and some gasses
coming out with high pressure. Lots of white/grey smoke. After about ten
minutes first flames. Heavy copper bus bars (150 mm2) are hot. They
wokred as heatsinks and transferred the heat from the destroyed cell to
next cells and surrounding air.
At this point we applied water. Batteries were in a box with sides
higher than cells. Water was about 10 celsius before applying. Water
added (100 litres) and cells are fully immersed. Show was over. Cells
removed from the box next day and rest of the cells are ok. Both cells
in the next to the metled cell have melted to one 3 cell block. Both
side cells have over 4 V as supposed.
Some of the cells from this test are still in use. Test was done in 2004.
During other similar test I inhaled massive amounts of the this white
smoke.(ALL FOR SCIENCE!). Not very intentionally thou. After complete
tests and blood analysis nothing implying of a poisoning was found. No
other effect on the test person but he is a complete Lithium head
nowadays :)
I have 350 Ah LiFeP cells to be penetration tested soon. Overcharge
tests were done with 150 Ah LiFeP cells and they did not even heat in
over 5V/cell. They got a dent in capacity and performance but no fires
or any other visually noticeable changes.
I have been next to such cell with overcharge situation (I personally
was not conducting the test). Cell voltage was 10.11V ! No effect which
would been possible to see from outside.
Personally I'm slowly dumping all Li-Co cells. They will be replaced
with Li-Fe cells. A bit less (20%) energy in same weight but the safety
factor is a multiplier in this case...
BMS is required not because of safety but for usability and long
lifetime. This is why I really hate the usage of BMS on any protection
circuitry you can get your hands on (99% of all "BMS" existing today are
such).
-Jukka
fevt.com
Michael Perry kirjoitti:
> http://www.allelectronics.com/battery_safety.html says to only charge
> Lithium batts in a fireproof container. Never leave unattended. It's very
> dangerous to breathe the fumes and all that is required is for lithium to
be
> exposed to air. That might explain a singe ruptured cell taking out the
> entire cargo. In an accident, it recommends removing yourself quickly and
> staying away for at least half an hour.
>
> http://www.findarticles.com/p/articles/mi_m0UBT/is_29_18/ai_n6280927 says
> for small fires, Lith-x or Halon will work. For lager fires they say to
> remove yourself and apply *lots* of water from a long range. (Remember,
the
> fumes are hazardous.)
>
>
> ----- Original Message -----
> From: "Danny Miller" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Friday, August 25, 2006 1:41 PM
> Subject: Re: Apple recalls 1.8 million laptop batteries / A123 battery
fire
>
>
>> Any idea how a lithium battery fire would be extinguished?
>>
>> Will exposed lithium would burn violently when mixed with water (like
>> sodium), or does this not occur with the lithium compounds used?
>>
>> There are several different classes of fire extinguisher, which one is
>> most appropriate? Are there types that would actually make the fire
> worse?
>> Danny
>>
>> Charles Whalen wrote:
>>
>>> Thanks Roger and Ed for explaining how these fires in cylindrical li-ion
>>> cells are usually the result of internal shorts caused by tiny metal
>>> particle contamination across the separator as an occasional but
>>> inevitable
>>> imperfection of the manufacturing process (which I assume must be
>>> difficult
>>> to nearly impossible to completely eliminate through standard and even
>>> enhanced quality control testing techniques -- if Sony can't do it, then
>>> surely nobody can, as Ed suggested).
>>>
>>> Combining this with Bill Dube's explanation of the mechanics of how
>>> such a
>>> fire would burn in an A123 (LiFeP) 26650 cell in response to my previous
>>> post asking about Craig Uyeda's A123 cell fire, I would guess that
>>> this type
>>> of occasional but inevitable manufacturing imperfection that you guys
>>> described is probably what caused the fire (due to just such an internal
>>> short) in that single one of Uyeda's A123 cells (out of a pack of 100
>>> cells), which burned up the "thimble-full of liquid electrolyte" in the
>>> cell, but not having any oxides within the cell to further fuel the
>>> fire (as
>>> is the case in the common LiCoO2 18650 industry-standard laptop
>>> cells), the
>>> fire burned itself out fairly quickly such that it was contained to that
>>> single cell and didn't spread in a chain reaction to the other 99
>>> cells in
>>> the pack, as almost always seems to be the case with assembled packs of
>>> LiCoO2 18650 laptop cells.
>>>
>>> Yeah, you're right that even the best, most sophisticated, most highly
>>> engineered BMS in the world with triple and quadruple redundant
> fail-safe
>>> backups is useless and can't do anything to prevent this sort of
>>> conflagration of LiCoO2 18650 laptop cells (caused by such an internal
>>> short
>>> within a single cell), but at least with A123 LiFeP 26650 cells, any
> such
>>> fire is likely to be of short duration, contained to the single cell,
> and
>>> won't erupt into a conflagration of the pack, as Bill Dube' explained.
>>>
>>> This leads to another question or two. I've heard that A123 is
>>> working on
>>> the development of large-format, EV-size cells in the 100-200Ah range.
>>> First, I wonder what their timetable is on that, at least for having
>>> prototype cells available. Second, I wonder if the much larger format
>>> cell
>>> and its manufacturing process (as distinct from that of a small cell) is
>>> inherently more amenable to solving/preventing this sort of
> manufacturing
>>> imperfection in the small cells where this type of tiny metal particle
>>> contamination occasionally occurs. Anyone have any insight into
>>> either of
>>> those two questions?
>>>
>>> Very interesting.
>>>
>>> Charles Whalen
>>>
>>>
>>> On Thursday, August 24, 2006 7:20 PM, Roger Stockton wrote:
>>>
>>>> Edward Ang wrote:
>>>>
>>>>> Dell confirmed that the problem is manufacturing
>>>>> contamination. Metal particles remained in the
>>>>> cell causing shorts across the separator.
>>>>> The problem is inside the cell, so, no amount of
>>>>> BMS could prevent the problem.
>>>>>
>>>>> The cells are made by Sony. Makes you wonder if
>>>>> Sony (the inventor of LiIon batteries) and one of the
>>>>> best consumer product manufacturers could not nail
>>>>> the manufacturing process, who else could, doesn't it?
>>>>>
>>>>> I wonder what impact would these recalls have on Tesla
>>>>> and AC Propulsion since they both actively advertise their
>>>>> systems use laptop computer LiIon batteries.
>>>>>
>>>>> This is one of the main reasons AIR Lab decided to focus
>>>>> on the robust Nimh battery. The last thing we need is an
>>>>> EV that burst into flame on the freeway. The local and
>>>>> national news would love to cover and exaggerate this.
>>>>>
>>>>> --
>>>>> Edward Ang
>>>>> President
>>>>> AIR Lab Corp
>>>>
>>>>
>>>> I wrote about this precise problem with the LiIon cylindrical cells
> upon
>>>> my return from the 2006 Advancements in Battery Technology & Power
>>>> Management conference in April.
>>>>
>>>> It appears *inevitable* that there will be failures of this sort
>>>> regardless of the manufacturer, although the frequency/likelihood is
>>>> dramatically higher with less well-controlled manufacturing processes
>>>> such as are often associated with lower-cost Chinese production.
>>>>
>>>> The safer cell chemistries may contain the damage to the single
>>>> defective cell rather than proceeding into an uncontrolled combustion
> of
>>>> neighbouring cells as well, but the issue seems to remain that the
>>>> cyclindrical cells are prone to this sort of internal shorting, and
>>>> there is nothing an external BMS can do about it.
>>>>
>>>> Cheers,
>>>>
>>>> Roger.
>>>
>>>
>>> On Wednesday, August 23, 2006 5:58 PM, Bill Dube wrote:
>>>
>>>> The electrolyte is an organic solvent. There is a thimble
>>>> full in each cell. If you short a cell, it can overheat and vent the
>>>> solvent. If there is an ignition source present (like the red-hot
>>>> shorted interconnect) you can get a flame. Once the solvent is gone,
>>>> or you starve the fire for oxygen, the flame goes out. You won't get
>>>> much flame in a closed battery box, for example, because you will
>>>> quickly use up the oxygen.
>>>>
>>>> This is distinctly different to what other types of Li-Ion
>>>> cells do. In those type cells fire is internal. These traditional
>>>> style of Li-Ion cell behave just like a road flare or a roman candle.
>>>> You can't put them out. They require no air to continue burning. The
>>>> whole pack is going to burn and there is nothing you can do but watch
>>>> (perhaps roast a marshmallow.)
>>>>
>>>> Quite a big difference.
>>>>
>>>> Bill Dube'
>>>>
>>>> At 02:07 PM 8/23/2006, Charles Whalen wrote:
>>>>
>>>>> That guy Craig Uyeda claims that one of his 100 A123 li-ion cells
>>>>> caught
>>>>> on fire. Does anyone know the circumstances of that and how it
>>>>> happened?
>>>>>
>>>>> I didn't think it was possible for A123 li-ions to catch fire
>>>>> because of
>>>>> their lithium-iron-phosphate chemistry being very distinct and much
>>>>> safer
>>>>> than the common lithium-cobalt-oxide chemistry used in the
>>>>> industry-standard 18650 laptop cells, in particular with no "oxide"
>>>>> to be
>>>>> liberated in the case of LiFeP. Valence and A123, both of which use
>>>>> lithium-iron-phosphate chemistries, claim that something like that (a
>>>>> fire) is not supposed to be able to happen with their batteries.
>>>>>
>>>>> Very curious and wondering how that happened with the A123 cell.
>>>>>
>>>>> Charles Whalen
>>>>>
>>>>>
>>>>> On Wednesday, August 23, 2006 9:00 AM, Mark Fisher wrote:
>>>>>
>>>>>> This thread
>>>>>>
>>>>>>
>
http://www.visforvoltage.com/forums/index.php?act=ST&f=31&t=4325&s=71612a004
543b13cb5673077c0e2711a
>>>>>>
>>>>>> has some discussion of the effects of lithium fires. Craig Ucheda is
> a
>>>>>> particularly extreme EV scooter enthusiast. Apparently the Fire
>>>>>> Marshall
>>>>>> isn't so thrilled by his hobby...
>>>>>>
>>>>>> Of course, gasoline burns pretty well too...
>>>>>>
>>>>>> http://www.youtube.com/watch?v=rdCsbZf1_Ng&NR
>>>>>>
>>>>>> Mark
>>>
--- End Message ---
--- Begin Message ---
Oops, sorry Karco all of this is from memory, my old HD with all
those links and emails is off-line.
http://www.karco.com/
I actually was able to get an itemized quote on testing from them. When
I first asked how much it costs, I was hit with how much testing do you
want to do and what people usually do. This is where I found out that it
is a cooperative "self-certification" system.
ie
http://www.nhtsa.dot.gov/cars/testing/comply/Mission/1_ovsc_1.html
There is unix based crash simulation software, not sure of price, but
needs a cluster.
The engineering and software methods are to save you time and, in long
term, money. The better your testing and capability of proving
compliance, the less your liabilty insurance per vehicle. The more units
you sell, the more of an issue it is. The scuttlebut is this is NOT a
linear scale .
If you are very confident of the product, a single physical crash test
is cheap, cheaper than having someone else guarantee your work for you
with a software tool. But if the test doesn't yield desirable results
(no such thing as failure, just data) You get to modify your design, and
try again, and again, and again......
I am not considering crash testing for a small scale producer.
I want to see someone go from prototype-->initial financing-> prototype
line->crash testing->certification-> major financing-> 30,000 units/year.
I wonder if the king of small scale crash testing, Racing facilities,
would test for me, and would the NHTSB accept results from such tests.
(Dreaming is free, initially)
--- End Message ---
--- Begin Message ---
I mentioned this once before. Lets all check our ICE car manuals for a
5K throttle position sensor.
I think the Mitsubishi PU is a 6K pot. This is MUKUNI fuel ijection in
the 93-98 range, dodge, mitsubishi, etc.
I checked my GM and my Nissan and the resistance was too high for our
use, but it would be nice if we can find a throttle body with integral
throttle closed switch and TPS that is around 5K. I think this problem
has been solved by all the car manufactures with the advent of fuel
injection.
--- End Message ---
--- Begin Message ---
So do these people want to sell some batteries or not?
http://www.boldertmf.com/product.htm
What's the price per cell?
--- End Message ---
--- Begin Message ---
Jeff Shanab wrote:
I mentioned this once before. Lets all check our ICE car manuals for a
5K throttle position sensor.
I think the Mitsubishi PU is a 6K pot. This is MUKUNI fuel ijection in
the 93-98 range, dodge, mitsubishi, etc.
I checked my GM and my Nissan and the resistance was too high for our
use, but it would be nice if we can find a throttle body with integral
throttle closed switch and TPS that is around 5K. I think this problem
has been solved by all the car manufactures with the advent of fuel
injection.
This is what my old mid-80's Chrysler Lebaron (TBI) used:
http://www.beiduncan.com/pdf/model_pdf/9811.9812.pdf
You can still get them for about $40 from mouser (much more from
Shucks/Kragen/Napa). I like this one because it has a built in return
spring, ~90 degress active rotation. CW & CCW models, and slotted
mounting holes for simple zero-adjusting.
--- End Message ---
--- Begin Message ---
Machine Type 3-wheel (street legal) Name *Silence* PT1 Model 60 KW Overall
external dimensions 13' length, 6' width, 4' height Tire Goodyear Dry
weight 1000-1500 lbs (with battery) Top speed More than 160 km/hr
Autonomy 80-100
km
100-200 km (bat. Opt.) Price $40,000 - 60,000 cdn
On 8/25/06, ROBERT GOUDREAU <[EMAIL PROTECTED]> wrote:
0 to 60 in 4 seconds.
http://www.electricbw.ca/silence.php
--- End Message ---
--- Begin Message ---
Jim Coate wrote:
> one sense lead for the BMS is definitely in trouble: connectors at
> both ends were corroded. But as I prepare to make a replacement, the
> strange part is the entire wire is corroded, inside the insulation!
That's not uncommon, particularly with stranded wire. There is actually
an air space between the strands, and sometimes between the plastic
insulation and the wire. Electrolyte that gets onto one end of the wire
wicks its way down the wire.
How far it gets down the wire depends on a lot of things, as you'd
expect. I've often seen it travel inches, or even feet. On really cheap
or really old wire that has been in a bad location, it can indeed travel
the entire length of the wire! The only option is to replace it.
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Victor Tikhonov wrote:
>
> Ralph,
>
> If you take apart a pedal sold in music stores for guitar sound effects
> and volume controls, you'll find that this method is used (for years...).
> There is a shutter gradually blocking light to the opto-detector,
> so "dead-spots" (as from mechanical wear of conventional pot) are
> impossible.
It depends on how close to a point source the light source and detector
are. With a light bulb and photoresistive cell, a simple shutter works
well. With an LED and phototransistor, you tend to get an all-or-nothing
response at the instant the edge of the shutter blocks the beam.
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Hi James,
Thanks for this suggestion. I have been having similar thoughts in the last
few days -- that I should go and buy another starter battery from Kubota and
store it dry along with a container of electrolyte, because of course once a
hurricane is bearing down on us with only a day or two until it strikes is
no time to find out that the starter battery's charge is down and maybe
won't accept and hold enough of a charge to start the generator, since all
hell and pandemonium break loose here in those last few days and it's
impossible to get anything, as there's a rush on everything, including, most
likely, those starter batteries at the Kubota factory office here.
As for your other suggestion, that is something I hadn't thought of and is
really a great idea. I wouldn't trust the starter battery in my Honda Civic
since we hardly ever drive that car, maybe only once every month or two just
to keep the fuel injection system from getting gunked up. But the two 12V
auxiliary batteries in our two RAV4-EVs would make great second and third
backups (with the first backup being a second Kubota starter battery stored
dry along with a container of electrolyte). The Toyota factory-supplied aux
batt in the RAV4-EV was notoriously poor and unreliable, and as with so many
other RAV4-EVs, both of mine had already died in my two cars. I wanted to
replace them with Optima YTs since the application is really more suited to
a deep-cycle batt and doesn't need any CCAs to start anything, but the YTs
were too big and wouldn't fit in the battery tray, so I bought Optima Red
Tops, which *are* CCA starter batteries, and that of course would be perfect
for starting the Kubota generator in an emergency where both the primary
battery and (stored dry) backup battery have for whatever reason both
failed. I have found by experience, the hard way, that Murphy's Law usually
prevails here during times of hurricanes, so one can never have too many
backups.
Now if I could just find some new HDPE or PVC 55-gallon drums. Our local
biodiesel distributor here said he'd try to source some for me but hasn't
come up with any. I'm going up to Harbor Freight this afternoon to see if
they've got any or know where I can find some locally. The intensity of
hurricane activity is definitely starting to pick up here as we move into
the peak of hurricane season.
Thanks for your excellent suggestions.
Charles Whalen
Delray Beach, FL
On Friday, August 25, 2006 10:41 PM, James Massey wrote:
At 06:11 AM 22/08/06 -0400, Charles Whalen wrote:
Well the Kubota guys felt
sorry for me and just gave me a free new batt but told me to put that
trickle charger on it from day one. Gotta go out and get some electrolyte
this week to fill up this new batt.
G'day Charles, Floridites and All
Something that I encountered via boatie types, if you want to keep a
battery as a backup emergency starting battery then store it new, dry, and
the acid in a container with it. Now when you are out of options - even
years later, pour the acid into the cells, wait 20 to 30 mins and presto!
a 3/4 charged battery to start your diesel from. So if you have another
battery (say in an ICE) that you can use for your monthly starts, keep
your new battery dry and fill it when you need to. Of course that may not
be appropriate if the genny is remote-start or the spouse or a child needs
to start it.
Hth,
Regards
[Technik] James
--- End Message ---
--- Begin Message ---
Thunder Sky.
I put one new video about piercing test on 30 AH Li-Mn cell from TS.
www.fevt.com/videos/LMP30_puncture.MPG
Ok. I admit... It's a pretty dull piece of video. Cell had still 4 V in
it after several minutes. Eventually it got down to zero.
-Jukka
p.s.- it is a raw video. size is a bit too big.
Don Cameron kirjoitti:
Hi Jukka, what brand of Li-Fe cells are you planning on using?
Don Cameron, Victoria, BC, Canada
see the New Beetle EV project www.cameronsoftware.com/ev
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Jukka Järvinen
Sent: August 26, 2006 7:58 AM
To: [email protected]
Subject: Re: Apple recalls 1.8 million laptop batteries / A123 battery fire
This will not perhaps apply on all brands.. but FYI.
Large Li-Co cell packs can be put down with water. It will lower the
tempereature nicely and prevent any further cell failures.
With bad design it is possible to get the domino effect and burn the whole
pack. I other words: make it too tight pack.
One tested setup:
15 pcs of 200 Ah Li-Co (ThunderSky brand) cells in one tightly packed
string. Overcharge (5V reached) applied to one cell in the middle.
Emergency vent wokred after few minutes as supposed and some gasses
coming out with high pressure. Lots of white/grey smoke. After about ten
minutes first flames. Heavy copper bus bars (150 mm2) are hot. They
wokred as heatsinks and transferred the heat from the destroyed cell to
next cells and surrounding air.
At this point we applied water. Batteries were in a box with sides
higher than cells. Water was about 10 celsius before applying. Water
added (100 litres) and cells are fully immersed. Show was over. Cells
removed from the box next day and rest of the cells are ok. Both cells
in the next to the metled cell have melted to one 3 cell block. Both
side cells have over 4 V as supposed.
Some of the cells from this test are still in use. Test was done in 2004.
During other similar test I inhaled massive amounts of the this white
smoke.(ALL FOR SCIENCE!). Not very intentionally thou. After complete
tests and blood analysis nothing implying of a poisoning was found. No
other effect on the test person but he is a complete Lithium head
nowadays :)
I have 350 Ah LiFeP cells to be penetration tested soon. Overcharge
tests were done with 150 Ah LiFeP cells and they did not even heat in
over 5V/cell. They got a dent in capacity and performance but no fires
or any other visually noticeable changes.
I have been next to such cell with overcharge situation (I personally
was not conducting the test). Cell voltage was 10.11V ! No effect which
would been possible to see from outside.
Personally I'm slowly dumping all Li-Co cells. They will be replaced
with Li-Fe cells. A bit less (20%) energy in same weight but the safety
factor is a multiplier in this case...
BMS is required not because of safety but for usability and long
lifetime. This is why I really hate the usage of BMS on any protection
circuitry you can get your hands on (99% of all "BMS" existing today are
such).
-Jukka
fevt.com
Michael Perry kirjoitti:
http://www.allelectronics.com/battery_safety.html says to only charge
Lithium batts in a fireproof container. Never leave unattended. It's very
dangerous to breathe the fumes and all that is required is for lithium to
be
exposed to air. That might explain a singe ruptured cell taking out the
entire cargo. In an accident, it recommends removing yourself quickly and
staying away for at least half an hour.
http://www.findarticles.com/p/articles/mi_m0UBT/is_29_18/ai_n6280927 says
for small fires, Lith-x or Halon will work. For lager fires they say to
remove yourself and apply *lots* of water from a long range. (Remember,
the
fumes are hazardous.)
----- Original Message -----
From: "Danny Miller" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, August 25, 2006 1:41 PM
Subject: Re: Apple recalls 1.8 million laptop batteries / A123 battery
fire
Any idea how a lithium battery fire would be extinguished?
Will exposed lithium would burn violently when mixed with water (like
sodium), or does this not occur with the lithium compounds used?
There are several different classes of fire extinguisher, which one is
most appropriate? Are there types that would actually make the fire
worse?
Danny
Charles Whalen wrote:
Thanks Roger and Ed for explaining how these fires in cylindrical li-ion
cells are usually the result of internal shorts caused by tiny metal
particle contamination across the separator as an occasional but
inevitable
imperfection of the manufacturing process (which I assume must be
difficult
to nearly impossible to completely eliminate through standard and even
enhanced quality control testing techniques -- if Sony can't do it, then
surely nobody can, as Ed suggested).
Combining this with Bill Dube's explanation of the mechanics of how
such a
fire would burn in an A123 (LiFeP) 26650 cell in response to my previous
post asking about Craig Uyeda's A123 cell fire, I would guess that
this type
of occasional but inevitable manufacturing imperfection that you guys
described is probably what caused the fire (due to just such an internal
short) in that single one of Uyeda's A123 cells (out of a pack of 100
cells), which burned up the "thimble-full of liquid electrolyte" in the
cell, but not having any oxides within the cell to further fuel the
fire (as
is the case in the common LiCoO2 18650 industry-standard laptop
cells), the
fire burned itself out fairly quickly such that it was contained to that
single cell and didn't spread in a chain reaction to the other 99
cells in
the pack, as almost always seems to be the case with assembled packs of
LiCoO2 18650 laptop cells.
Yeah, you're right that even the best, most sophisticated, most highly
engineered BMS in the world with triple and quadruple redundant
fail-safe
backups is useless and can't do anything to prevent this sort of
conflagration of LiCoO2 18650 laptop cells (caused by such an internal
short
within a single cell), but at least with A123 LiFeP 26650 cells, any
such
fire is likely to be of short duration, contained to the single cell,
and
won't erupt into a conflagration of the pack, as Bill Dube' explained.
This leads to another question or two. I've heard that A123 is
working on
the development of large-format, EV-size cells in the 100-200Ah range.
First, I wonder what their timetable is on that, at least for having
prototype cells available. Second, I wonder if the much larger format
cell
and its manufacturing process (as distinct from that of a small cell) is
inherently more amenable to solving/preventing this sort of
manufacturing
imperfection in the small cells where this type of tiny metal particle
contamination occasionally occurs. Anyone have any insight into
either of
those two questions?
Very interesting.
Charles Whalen
On Thursday, August 24, 2006 7:20 PM, Roger Stockton wrote:
Edward Ang wrote:
Dell confirmed that the problem is manufacturing
contamination. Metal particles remained in the
cell causing shorts across the separator.
The problem is inside the cell, so, no amount of
BMS could prevent the problem.
The cells are made by Sony. Makes you wonder if
Sony (the inventor of LiIon batteries) and one of the
best consumer product manufacturers could not nail
the manufacturing process, who else could, doesn't it?
I wonder what impact would these recalls have on Tesla
and AC Propulsion since they both actively advertise their
systems use laptop computer LiIon batteries.
This is one of the main reasons AIR Lab decided to focus
on the robust Nimh battery. The last thing we need is an
EV that burst into flame on the freeway. The local and
national news would love to cover and exaggerate this.
--
Edward Ang
President
AIR Lab Corp
I wrote about this precise problem with the LiIon cylindrical cells
upon
my return from the 2006 Advancements in Battery Technology & Power
Management conference in April.
It appears *inevitable* that there will be failures of this sort
regardless of the manufacturer, although the frequency/likelihood is
dramatically higher with less well-controlled manufacturing processes
such as are often associated with lower-cost Chinese production.
The safer cell chemistries may contain the damage to the single
defective cell rather than proceeding into an uncontrolled combustion
of
neighbouring cells as well, but the issue seems to remain that the
cyclindrical cells are prone to this sort of internal shorting, and
there is nothing an external BMS can do about it.
Cheers,
Roger.
On Wednesday, August 23, 2006 5:58 PM, Bill Dube wrote:
The electrolyte is an organic solvent. There is a thimble
full in each cell. If you short a cell, it can overheat and vent the
solvent. If there is an ignition source present (like the red-hot
shorted interconnect) you can get a flame. Once the solvent is gone,
or you starve the fire for oxygen, the flame goes out. You won't get
much flame in a closed battery box, for example, because you will
quickly use up the oxygen.
This is distinctly different to what other types of Li-Ion
cells do. In those type cells fire is internal. These traditional
style of Li-Ion cell behave just like a road flare or a roman candle.
You can't put them out. They require no air to continue burning. The
whole pack is going to burn and there is nothing you can do but watch
(perhaps roast a marshmallow.)
Quite a big difference.
Bill Dube'
At 02:07 PM 8/23/2006, Charles Whalen wrote:
That guy Craig Uyeda claims that one of his 100 A123 li-ion cells
caught
on fire. Does anyone know the circumstances of that and how it
happened?
I didn't think it was possible for A123 li-ions to catch fire
because of
their lithium-iron-phosphate chemistry being very distinct and much
safer
than the common lithium-cobalt-oxide chemistry used in the
industry-standard 18650 laptop cells, in particular with no "oxide"
to be
liberated in the case of LiFeP. Valence and A123, both of which use
lithium-iron-phosphate chemistries, claim that something like that (a
fire) is not supposed to be able to happen with their batteries.
Very curious and wondering how that happened with the A123 cell.
Charles Whalen
On Wednesday, August 23, 2006 9:00 AM, Mark Fisher wrote:
This thread
http://www.visforvoltage.com/forums/index.php?act=ST&f=31&t=4325&s=71612a004
543b13cb5673077c0e2711a
has some discussion of the effects of lithium fires. Craig Ucheda is
a
particularly extreme EV scooter enthusiast. Apparently the Fire
Marshall
isn't so thrilled by his hobby...
Of course, gasoline burns pretty well too...
http://www.youtube.com/watch?v=rdCsbZf1_Ng&NR
Mark
--
Jukka Järvinen
R&D Director
Oy Finnish Electric Vehicle Technologies Ltd
Teollisuuskatu 24 A3
11100 RIIHIMÄKI
FINLAND
VAT ID: FI18534078
jukka.jarvinen(a_t)fevt.com
mobile +358-440-735705
phone +358-19-735705
fax +358-19-735785
--- End Message ---
--- Begin Message ---
Several times in the past I have suggested that NEDRA should keep
records for best 60 foot times for Electric Jr Dragsters.
1) There is no NHRA restriction on 60 ft times for Jr Dragsters.
2) A low 60 ft time is difficult to get and requires a very good
set-up on the machine.
3) It is one of the more difficult parts of the race to do well, at
least technically.
4) EVs typically kick butt in 60 ft compared to ICEs, so the numbers
should be impressive.
5) A hard launch is the most fun part of the race.
Bill Dube'
--- End Message ---
--- Begin Message ---
I doubt the built-in return springs are capable of acting as the pedal
spring.
What it might do is compensate for any slack in the system. For example
if you had a "D"-cut shaft that is a few mils too small to be a tight
fit, there could be a few degrees of slack. But with a return spring it
will always be pulled tight in one direction, making the slack a nonissue.
Slack may not be an issue to begin with. I suppose that, provided you
orient it in the proper direction, if the pedal assembly totally falls
apart the springs would ensure the pedal sensor returns to 0. Hopefully
this is not a likely problem either.
Danny
Steven Ciciora wrote:
The "Farnell in one" logo reminded me of the "Newark
in one" logo, so I searched over there. If you go to
www.newark.com and search for newark part number
70C3473, you will find it is a special order item, one
of them for $32.32 each, available in 71 days. The
one with a hole in it (manufacture pn 9710002, newark
pn 02J5720) is $66.34, 89 day lead time. I already
have a pot box, but if I needed one, or was having
problems with one, I'd consider a throttle position
sensor off a fuel injected car. Hmmm, I think I'll
see what the resistance range is of the one on my gas
car, and if it's not too much $, order a spare, and
see about making a mounting bracket for it... but I
don't think the ones in my gas cars have built in
return springs.
- Steven Ciciora
--- Dave Cover <[EMAIL PROTECTED]> wrote:
I like it. Are these available affordably in the US?
Ordered from them it would be about 4 to 5
times the price of a good quality 5k pot.
Dave Cover
--- Paul Compton <[EMAIL PROTECTED]> wrote:
You know, there's a reason I don't read this list
on a regular basis and it
has to do with the tendancy of some list members
to ignore proven off the
shelf solutions to simple problems. I've posted
many times over the years on
alternatives to the convenient, but expensive and
not very reliable Curtis
potbox, but almost always been ignored.
I'll try again, just in case anybody is listening.
If you've got a controller with a 0-5K, or 5-0K,
or a potentiometer input,
then take a look at;
http://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=4246718
and
http://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=7006457
Automotive rated conductive plastic pots with 'D'
shaft activation and built
in return springs.
5 million full cycles.
10 million 'dither' cycles.
Paul Compton
www.sciroccoev.co.uk
www.bvs.org.uk
www.morini-mania.co.uk
www.compton.vispa.com/the_named
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--- End Message ---
