EV Digest 6026
Topics covered in this issue include:
1) Re: Electrovair Corrections
by "Death to All Spammers" <[EMAIL PROTECTED]>
2) Re: parallel connections Question
by "David Roden" <[EMAIL PROTECTED]>
3) Re: Gliders
by "David Roden" <[EMAIL PROTECTED]>
4) Re: parallel connections Question
by "Rush" <[EMAIL PROTECTED]>
5) Re: Fuel gauge Peukert correction, was: lee's emeter companion?
by Danny Miller <[EMAIL PROTECTED]>
6) Re: Are we missing the boat on charging infr.?
by "David Roden" <[EMAIL PROTECTED]>
7) RE: Fuel gauge Peukert correction, was: lee's emeter companion?
by "Roger Stockton" <[EMAIL PROTECTED]>
8) RE: Electrovair Corrections
by "Roger Stockton" <[EMAIL PROTECTED]>
9) RE: Fuel gauge Peukert correction, was: lee's emeter companion?
by Randall Prentice <[EMAIL PROTECTED]>
10) Re: Floodies/Batt. murder mystery/Thanks to Roger & Roland
by "Chuck Hursch" <[EMAIL PROTECTED]>
11) Re: Fuel gauge Peukert correction, was: lee's emeter companion?
by Danny Miller <[EMAIL PROTECTED]>
12) Re: parallel connections Question
by "Phil Marino" <[EMAIL PROTECTED]>
13) A123 & nanopollution
by "Osmo S." <[EMAIL PROTECTED]>
14) Re: A123 & nanopollution
by "Mark McCurdy" <[EMAIL PROTECTED]>
15) Re: A123 & nanopollution
by [EMAIL PROTECTED]
16) Re: Floodies/Batt. murder mystery/Thanks to Roger & Roland
by "Roland Wiench" <[EMAIL PROTECTED]>
17) Small request
by "Michael Trefry" <[EMAIL PROTECTED]>
18) Re: A123 Group buy?
by "Mike Phillips" <[EMAIL PROTECTED]>
19) Re: A123 & nanopollution
by "Mike Phillips" <[EMAIL PROTECTED]>
20) Re: A123 & nanopollution
by "Osmo S." <[EMAIL PROTECTED]>
21) Re: parallel connections Question
by "David Roden" <[EMAIL PROTECTED]>
--- Begin Message ---
> > Now I've said my bit, so I'll leave you and Lee to go at it ;^>
>
> Actually, I'm not going to argue with him. I'll provide facts or
further
> data if requested, but I'm not trying to convince him or "win" any
debate.
>
Argument isn't a good decription - difference of opinion is more apt.
--- End Message ---
--- Begin Message ---
On 15 Oct 2006 at 16:07, Storm Connors wrote:
> Is it better to make 2
> strings of 12 batteries and put them in parallel or to patallel pairs of
> batteries and put the pairs in series?
Believe it or not, both. Make two high-current strings and parallel them at
the ends. Then connect lighter jumpers from battery to battery across the
strings, to assist in module balancing. This gives the advantages of both
schemes.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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--- Begin Message ---
On 15 Oct 2006 at 14:57, [EMAIL PROTECTED] wrote:
> GM sold the Geo Metro and S-10 to Solectria as Gliders.
Yes, but GM sold them Metro gliders only for a few years. (I have the info
on when the program started somewhere, but I don't have time to search for
it now.) It dropped the price of the car from (going from memory here) $36k
to $31k or so.
Prior to that, they bought new cars off the lot and eviscerated them. I
heard they had quite a pile of exhaust systems and gas tanks behind their
building at one time.
>From what they told me, Solectria put a lot of effort into convincing GM to
sell them gliders. GM wanted to make sure that their finished product would
not cast any kind of negative image on their vehicles.
Ford had a similar policy for selling pickup gliders to "qualified
upfitters." It was based on their policies for selling vans to van
customizers. IIRC, only one or two firms ever qualified to purchase pickup
gliders from Ford.
Solectria were successful in obtaining the gliders, but not too many years
after that, GM stopped offering the Metro in the US market. I'm sure that
was one reason that Solectria finally gave up on the Force.
I don't believe GM ever sold them S10 gliders. I'm pretty sure they no
longer offered the E10 by the time they negotiated that deal with GM.
My guess is that you'll always find it easier to buy gliders from small
and/or struggling automakers. However, this has its own hazards.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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--- End Message ---
--- Begin Message ---
For the purposes of discussion, lets say your batteries are 12v with a 100 ah
reserve. So if you put them into 2 series strings of 12 each and parallel the 2
strings you'll have a 144 v system with 200 ah reserve. If you put them into
12 series strings of 2 each and parallel the 12 strings, them you'll have a 24
v system with a 1200 ah reserve..
It makes no sense to have a battery pack that is 24v with a 1200 ah reserve. So
make it 2 parallel strings of 12 batteries in series.
Rush
Tucson AZ
www.ironandwood.org
----- Original Message -----
From: "Storm Connors" <[EMAIL PROTECTED]>
To: "List EV" <[email protected]>
Sent: Sunday, October 15, 2006 4:07 PM
Subject: parallel connections Question
>I have 24 12v batteries to put into a 144v pack. Is it better to make 2
>strings of 12 batteries and put them in parallel or to patallel pairs of
>batteries and put the pairs in series?
> Thanx,
> storm
>
>
--- End Message ---
--- Begin Message ---
I do not believe your scheme is mathematically valid for an e-meter.
Peukert's does not calculate capacity based on the history of the rates
of discharged current. It's actually a measure of how much current can
be drawn for the current state of charge. Calculating for one data
point, the numbers you give seem to be incorrect. I apologize in
advance if I've read them wrong or screwed up my version of the calcs,
but please read on.
Taking your initial data for Peukert's, my calculations:
The battery can only supply 300 amps for 87.6 a-h. Another way of
stating this is that the battery can only supply 300 amps as long as the
charge state has over 584 a-h in it. Right?
So, at the end of period #3, we are consuming 300 amps and have used 35
real a-h, there are 636.6 a-h in the battery.
Peukert's tells us the battery can supply can supply another 52.6 a-h at
300 amps until it won't be able to sustain that discharge rate, so the
figure should be 60%, not 69%. At that point there at 0 a-h of 300
amp discharge current left. However, there are still plenty of amp-hrs
left for a 50 amp or 100 amp discharge rate.
That's why an e-meter compensating for Peukert's MUST go up when you
start driving lighter. The thing to understand is that this is not a
flaw of the meter's algorithm. Peukert's is based on how much current
you need in the future, not the rates you've used in the past.
Unfortunately EVs don't use anything near fixed discharge rates. Since
the meter cannot read your mind (yet), Peukert's predictions will always
be unreliable.
Danny
Victor Tikhonov wrote:
As we drive and discharge the battery, the
capacity remaining is decremented at regular intervals by the amount of
Ah consumed during that interval, multiplied by an appropriate rate
dependant correction factor.
Ah Discharge Guage Ah Guage
Removed Rate (A) Remaining Indication
======= ========= ========= ==========
0 0 671.6 F (1.00)
25 100 542.1 7/8-3/4 (0.81)
10 300 465.4 3/4-5/8 (0.69)
30 50 344.2 1/2 (0.51)
40 100 137.0 1/4-1/8 (0.20)
--- End Message ---
--- Begin Message ---
The purpose of this list is not to challenge one another to produce examples
of positive or negative posts - except those that are on batteries. ;-)
Please, give it a rest, guys. If you want to beat each other with words, or
for that matter with 2x4s, please do it in private email. This kind of
quarreling is not a beneficial exchange for the list.
Thanks.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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--- End Message ---
--- Begin Message ---
Victor Tikhonov wrote:
> No, Roger, that's not how these meters work, They work similarly
> to the meter on your house - if those would be re-settable to zero,
> you'd know *very* exactly how many Wh you've spent since reset.
I'm not sure what you are diasgreeing with Victor. I too have an
accurate Ah (also Wh) meter in my EV, and it behaves *exactly* as you
describe, which happens to be *exactly* the vehaviour my example
illustrates.
The meter counts Ah (Wh) very accurately, and accumulates to a larger
-ve value the furhter you discharge the pack. My meter (like yours, it
sounds), starts off at 0Ah when reset; my example assumes the ability to
program some other "full" value into the meter, but as I'm sure you
appreciate this has no effect on the accuracy with which the meter
measures Ah and indicates it. All it does is shift the values by this
initial amount so that by starting at 143Ah rather than 0Ah, the first
Ah that the meter measures with its 0.1Ah accuracy results in a display
of 142Ah instead of -1Ah.
Or, if you prefer, we program a little 'fuel guage brain' black box with
our best guess of the battery's present 'full' capacity at the present
temperature, etc. and it takes the Ah meter's output which is simply the
Ah consumed since reset (full), and this black box performs the
calculation:
Estimated
remaining Ah = estimated full Ah - actual consumed Ah since full
fraction =================================================
estimated full Ah
And displays this result on a fuel guage.
> I'm not sure how meter can read more or less optimistically
> toward the end if there is no end - it just counts Ah spent.
A plain Ah meter can't, but by comparing the result of using an Ah
counter's accurate measure of the Ah consumed to compute the fraction of
'full' capacity remaining to the result of using a Peukert corrected
meter, we can see that the estimates diverge by larger and larger
amounts as the Ah consumed approaches the actual capacity of our
battery.
> The rate of Wh being consumed natural;y doe not depend
> on the SOC,
In the Peukert-corrected guage example I provided, the rate of Wh
consumption also did not depend on the SOC. The actual rate of Wh
comsumption obviously still depends on all the factors you listed, but
the rate at which the fuel guage decreased in the example also depended
upon the effect that the magnitude of the present Wh consumption has on
the available capacity of the battery.
> So I'm not disagreeing with you or stating that attempts
> to predict amount of energy (or miles) are useless.. All
> I'm telling is that definition of "total" is too fuzzy to
> get estimated even approximately (if driving pattern is
> unknown and that was the condition for this discussion).
The condition that the *future* driving pattern is unknown still
remains, but the point of my participation in this thread was to help
you recognise that it is possible to provide a more accurate fuel guage
(*not* a distance remaining guage) by including Peukert compensation for
lead acid batteries because an indication of the energy remaining in the
'tank' depends only upon the *past* driving pattern (which the guage
knows because it has observed it).
> Software can do anything as long as the task is formalized enough.
> No one has done it satisfactorily simply because it's not doable.
I wonder how many times that's been said in the past about other
'impossible' tasks that were later proven to be quite doable? ;^>
Fine with me, though, as long as you take the view that it is impossible
to do an accurate or useful EV fuel guage, you certainly won't be
producing one, and that leaves the market wide open for someone else
(perhaps even me ;^).
> Interesting and informative discussion but I'm afraid may become
> boring for the list. Should we rest the case?
OK.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
> The SAE paper provided quite a lot of detail about the old
> SCR inverter. It was very advanced for its time. It *did*
> have a huge capacitor bank, to filter the battery current
> to be approximately DC; just as is done in today's
> controllers.
I suspected this to be the case based on your quote of the reviewer's
comments regarding the silence when driving the Electrovair. My point
was mainly to force John to recognise that he can't have it both ways;
the SCR controller could not be distressingly noisy unless it was also
making much less efficient use of its batteries than the EV1's
controller, which would then make it that much more amazing that it
managed to come as close to the EV1's range as it did. ;^>
> One weakness of the SCR inverter was that it had trouble
> starting the motor smoothly from a dead stop. It took
> about 50 usec minimum to turn the SCR on and back off.
> In this time, the motor current would ramp up to a fairly
> high level, which meant fairly high torque. They had to
> pulse the motor many times per second to get a low average
> current and torque. This meant torque pulsations if you
> were trying to creep forward. You'll find this same effect
> in SCR controllers for series DC motors.
Funny you should say that, as I *am* running an SCR controller in my EV,
and haven't noticed this effect at all. The only related problem I've
noticed is that the throttle seems to go from 0 to 2 or 3 instead of
smoothly up from 0 to 1 (on a scale of 1-10, 10 being full throttle),
but even this put a great EV grin on my face as I eased my EV out of the
garage for the first time... Not thinking, I used first gear and when I
eased gently onto the throttle I came out with both front tires
squealing and a nice matching set of black strips christening the garage
floor ;^).
>
> > Now I've said my bit, so I'll leave you and Lee to go at it ;^>
>
> Actually, I'm not going to argue with him. I'll provide facts
> or further
> data if requested, but I'm not trying to convince him or
> "win" any debate.
> --
> Ring the bells that still can ring
> Forget the perfect offering
> There is a crack in everything
> That's how the light gets in -- Leonard Cohen
> --
> Lee A. Hart, 814 8th Ave N, Sartell MN 56377,
> leeahart_at_earthlink.net
>
>
--- End Message ---
--- Begin Message ---
AFWIK
Peukert's is a factor allowing for the I^2 R losses in the battery (Chemical
as well as internal Resistance).
The reduction in capacity is the Heat Given to the battery is losses, it is
not extra capacity but is a measure of the capacity wasted inside the
nattery during higher discharge currents.
If you regard the battery as having a fixed A/H rate then subtract A/H's
used times the Peukert factor for each part of the discharge what you have
left is the A/H remaing to be used in the battery. This is disguised a
little by the varying voltage cutoff point on discharge which is really the
normal discharge point minus the volt drop of the internal resistance under
that load.
If I'm talking porkies feel free to correct me, I not a wrench yet....
Regards
Randall Prentice
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] On Behalf Of Danny Miller
> Sent: Monday, 16 October 2006 8:19 p.m.
> To: [email protected]
> Subject: Re: Fuel gauge Peukert correction, was: lee's emeter
> companion?
>
>
> I do not believe your scheme is mathematically valid for an e-meter.
> Peukert's does not calculate capacity based on the history of
> the rates
> of discharged current. It's actually a measure of how much
> current can
> be drawn for the current state of charge. Calculating for one data
> point, the numbers you give seem to be incorrect. I apologize in
> advance if I've read them wrong or screwed up my version of
> the calcs,
> but please read on.
>
> Taking your initial data for Peukert's, my calculations:
> The battery can only supply 300 amps for 87.6 a-h. Another way of
> stating this is that the battery can only supply 300 amps as
> long as the
> charge state has over 584 a-h in it. Right?
> So, at the end of period #3, we are consuming 300 amps and
> have used 35
> real a-h, there are 636.6 a-h in the battery.
>
> Peukert's tells us the battery can supply can supply another
> 52.6 a-h at
> 300 amps until it won't be able to sustain that discharge
> rate, so the
> figure should be 60%, not 69%. At that point there at 0 a-h of 300
> amp discharge current left. However, there are still plenty
> of amp-hrs
> left for a 50 amp or 100 amp discharge rate.
>
> That's why an e-meter compensating for Peukert's MUST go up when you
> start driving lighter. The thing to understand is that this is not a
> flaw of the meter's algorithm. Peukert's is based on how
> much current
> you need in the future, not the rates you've used in the past.
> Unfortunately EVs don't use anything near fixed discharge
> rates. Since
> the meter cannot read your mind (yet), Peukert's predictions
> will always
> be unreliable.
>
> Danny
>
> Victor Tikhonov wrote:
>
> >> As we drive and discharge the battery, the
> >> capacity remaining is decremented at regular intervals by
> the amount
> >> of Ah consumed during that interval, multiplied by an appropriate
> >> rate dependant correction factor.
> >> Ah Discharge Guage Ah Guage
> >> Removed Rate (A) Remaining Indication
> >> ======= ========= ========= ==========
> >> 0 0 671.6 F (1.00)
> >> 25 100 542.1 7/8-3/4 (0.81)
> >> 10 300 465.4 3/4-5/8 (0.69)
> >> 30 50 344.2 1/2 (0.51)
> >> 40 100 137.0 1/4-1/8 (0.20)
> >>
> >
>
>
>
--- End Message ---
--- Begin Message ---
Roland,
I was looking at your post of Sept. 29 again. For all that read
this, remember the 1.75 SG is a typo and should be read as 1.275
SG.
>
> You may have given me a clue, when you said your batteries were
deliver with
> low electrolyte.
>
> If I remember right, is that the water to acid ratio is about 5
parts of
> water to 3 parts of water.
>
> Water being 1.0 sg and sulfuric acid is 1.8. Adding 5 (five
parts of water)
> to 1.8+1.8+1.8 (three parts of acid) = 10.4
>
> Divide 10.4 by eight parts = 1.3 SG electrolyte while its hot.
When cool
> down it will be about 1.75 SG.
So here's something basic I'm tripping up on. I assume your 1.3
SG and 1.275 SG are non temperature compensated. Isn't the hot
electrolyte less dense, hence shouldn't that have a lower SG
reading than the cold stuff? If you temperature-compensate the
readings, then hot and cold no longer really matter, right?
>
> If a container (cell) is low with 1.75 SG electrolyte (reading
1.75 sg)
> than adding just water might add another part of water or:
>
> (6 x 1.0)+ 3 x 1.8) = 11.4
>
> 11.4/9 parts = 1.26 SG while hot and may have reduce it to
1.24 when cool.
>
> So it took more over charging increase the electrolyte to 1.257
SG. even
> though the plates were charge to 100%.
>
> If the original reading of the electrolyte was at 1.75 SG and
you added
> water which reduce it to 1.24 SG, You may have over charge it
to raise the
> SG.
>
> If new batteries are low and the factory did not fill the cell
all the way
> out, you must add the same SG electrolyte to the proper level.
>
> The white floating crystals is the sulfate or SO4 from the
negative plates,
> meaning you are releasing the sulfate from the negative plates
at a too fast
> of a charge. The sulfate is ejecting from the negative plates
as particles
> instead of dissolving very slowly.
Well, my bulk charge rate has been 10-11A on a 235A-hr battery.
US Battery recommendation as I recall is to charge at C/10, or in
my case about 23A, so I'm well under. I would charge faster, but
don't have the charger or AC line to do so. I can get to 15A DC
into the pack without tripping the 20A circuit breaker in my
apartment, but to run it at this rate is unsafe, as I'm way over
the NEC 80% limit (16A).
>
[snip]
> The problem now, is to find out what the real charge rating of
the plates
> are at. They may no longer correspond to the SG of the diluted
acid.
>
> One way that might work, is to let the electrolyte level get
down to the
> level you thought was low. Charge the batteries at a low rate
as to not to
> eject more material as high SG you can go.Read the SG which
should be higher
> now, because there is less water by removing 1 part.
So should I charge at something like 2A? That is, do a discharge
of some (?) depth, then charge real slow. That could take days,
but maybe a weekend and a day or two could be arranged. zzz...
>
> Then finish adding electrolyte as should have been done in the
beginning.
>
> This is going to be better than nothing. It may not work, but
I would give
> it a try.
>
Chuck
--- End Message ---
--- Begin Message ---
I believe this is indeed incorrect.
Peukert's does not model I^2*R losses at all. Rather, as far as I
understand it, the source voltage drops because the surface of the
plates reach a lower charge state- and thus a lower voltage-during
depletion from a high discharge. Basically the chemistry can't keep
up. As the solid and liquid reagents involved in this reaction are
consumed, the potential speed of the reaction slows down just like in
any other chemical process, basically because the materials still in an
active state have a harder time finding each other. While resistive
losses are always present, that's not what Peukert's is about.
Here's the practical thing though. If we have a 100 amp-hr battery and
discharge it at C3 (300amps) until we've used 50 amp-hrs and Peukert's
tells us the battery has only had 50 amp-hrs of capacity at 300 amps so
it's depleted, what do we have in the battery? The reality is there are
still 50 amp-hrs left in the battery. Just not 50 amp-hrs that can
supply 300 amps. If you only drew 15 amps to limp home you'd be able to
get virtually all 50 amp-hrs out of it before reaching the stop voltage.
Now here's the thing. If you're at 50 amp-hrs, does it matter if you
got there by drawing 300 amps or 10 amps? As I understand it, no!
Peukert's is just saying that this battery must have over 50 amp-hrs
left in it to provide 300 amps. That's what I find was wrong with the
initial post which proposed how an e-meter should work. It is
completely wrong to say that amp-hrs consumed should be multiplied by
the Peukert factor, that's not how Peukert's works.
Danny
Randall Prentice wrote:
AFWIK
Peukert's is a factor allowing for the I^2 R losses in the battery (Chemical
as well as internal Resistance).
The reduction in capacity is the Heat Given to the battery is losses, it is
not extra capacity but is a measure of the capacity wasted inside the
nattery during higher discharge currents.
If you regard the battery as having a fixed A/H rate then subtract A/H's
used times the Peukert factor for each part of the discharge what you have
left is the A/H remaing to be used in the battery. This is disguised a
little by the varying voltage cutoff point on discharge which is really the
normal discharge point minus the volt drop of the internal resistance under
that load.
If I'm talking porkies feel free to correct me, I not a wrench yet....
Regards
Randall Prentice
--- End Message ---
--- Begin Message ---
So, each pair of paralleled batteries is called a "module"? That's the
same as what people mean by "buddy pair", right?
Phil
From: "David Roden" <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Re: parallel connections Question
Date: Mon, 16 Oct 2006 03:09:03 -0400
On 15 Oct 2006 at 16:07, Storm Connors wrote:
> Is it better to make 2
> strings of 12 batteries and put them in parallel or to patallel pairs of
> batteries and put the pairs in series?
Believe it or not, both. Make two high-current strings and parallel them
at
the ends. Then connect lighter jumpers from battery to battery across the
strings, to assist in module balancing. This gives the advantages of both
schemes.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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To send a private message, please obtain my email address from
the webpage http://www.evdl.org/help/ .
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--- Begin Message ---
"Nanopollution is a generic name for all waste generated by
nanodevices or during the nanomaterials manufacturing process. This
kind of waste may be very dangerous because its size. It can float in
air the and might easily penetrate animal and plant cells causing
unknown effects. Most human made nanoparticles do not appear in
nature so living organism may not have appropriate means to deal with
this kind of waste. It is probably one great challenge to
nanotechnology: How to deal with its nanopollutants and nanowaste."
What´s your opinion about this. Should we take it into account when
considering A123s and other nanotechnology batteries?
I suppose there just isn´t enough information available about this
issue yet. I sent a question to the A123 manufacturer, but no reply
(although I think they don´t answer mails sent by individuals anyway).
Osmo
--- End Message ---
--- Begin Message ---
Most of those technologies require clean rooms, with air control systems.
Would be very easy to control those micro particles.
Keep the room under negative pressure and the exhaust running through a
furnace. The negative pressure would keep particles from escaping and the
furnace would burn the particles instantly, turning them into either metal
vapor (which would laminate the exhaust path when it cooled) or turn it into
soot.
----- Original Message -----
From: "Osmo S." <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, October 16, 2006 5:11 AM
Subject: A123 & nanopollution
"Nanopollution is a generic name for all waste generated by
nanodevices or during the nanomaterials manufacturing process. This
kind of waste may be very dangerous because its size. It can float in
air the and might easily penetrate animal and plant cells causing
unknown effects. Most human made nanoparticles do not appear in
nature so living organism may not have appropriate means to deal with
this kind of waste. It is probably one great challenge to
nanotechnology: How to deal with its nanopollutants and nanowaste."
What´s your opinion about this. Should we take it into account when
considering A123s and other nanotechnology batteries?
I suppose there just isn´t enough information available about this
issue yet. I sent a question to the A123 manufacturer, but no reply
(although I think they don´t answer mails sent by individuals anyway).
Osmo
--- End Message ---
--- Begin Message ---
I would recommend contacting the nearest semiconductor chip fab and ask for a
tour. Tours in a fab are fastinating and informative. They should be able to
answer your question.
I worked at Applied Materials for about two years as a final test technician.
Applied Materials manufacture the machines that chip fabs use to make micro
chips - like the ones used in your computer, cell phone etc. These chips are
manufactured using nano technology and it is all done in very tight clean room
environment. That is not to prevent contaminates from escaping into the
atmosphere, but to prevent particles in the air from contaminating the micro
chips. Although, for the same reason, contaminates from the manufacturing
process does not enter the atmosphere.
Anyway, nano technology is not a new thing. New for batteries perhaps.
Just my two nano's worth!
Ken
-----Original Message-----
From: [EMAIL PROTECTED]
To: [email protected]
Sent: Mon, 16 Oct 2006 5:11 AM
Subject: A123 & nanopollution
"Nanopollution is a generic name for all waste generated by nanodevices or
during the nanomaterials manufacturing process. This kind of waste may be very
dangerous because its size. It can float in air the and might easily penetrate
animal and plant cells causing unknown effects. Most human made nanoparticles
do not appear in nature so living organism may not have appropriate means to
deal with this kind of waste. It is probably one great challenge to
nanotechnology: How to deal with its nanopollutants and nanowaste."
What´s your opinion about this. Should we take it into account when considering
A123s and other nanotechnology batteries?
I suppose there just isn´t enough information available about this issue yet. I
sent a question to the A123 manufacturer, but no reply (although I think they
don´t answer mails sent by individuals anyway).
Osmo
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--- End Message ---
--- Begin Message ---
Hello Chuck,
In mixing H2S04 with H20 (add acid to water - not water to acid) cause a
heat reaction, making the SG reading about 1.300 at the time. After cool
down, it will read about 1.275.
Yes, if you boil the electrolyte or do a high rate charging that will bubble
off the H20, than you will evaporated the some of the H20, increasing the
ratio of Acid to water making the SG higher.
After the acid is pour into the water, the top layer of the electrolyte will
read higher at first and than when cool, the heaver acid settles to the
bottom of the electrolyte, now the top layer where you pull out your sample
will read less.
This is way some people think there battery is discharge after it's been
setting around for a long time, the acid settle to the bottom making the top
weak.
Always first charge the battery to make it bubble a bit so it will mix the
acid through out the electrolyte, then take a SG reading.
It is recommended to charge the battery at a minimum of C/10, so as to do
this mixing, plus to extract the deep sulfate (SO4) from the negative
plates.
I charge my batteries at 15% to 20% of the 260 AH rate or about 40 to 50
amps. These batteries are now going on 5 years old. All are reading 1.275+
sg. 25 batteries out of 30 are balance in with 0.01 volt of each other and
the other five are from 0.02 to 0.04 volt difference.
At 50% discharge the electrolyte level may be about 1/2 above the plates, do
not add water at this time. First charge the batteries to about 85% to 90%
SOC (state of charge) and than add water. Continue to charge to 100% so the
water will mix better with the electrolyte.
At this time when I add water, which may be every 3 or 4 months, I will do a
equalized charge at the time. If some batteries are not in with 0.01 volt
of each other, I will than will charge lower voltage batteries, with a
separated smart charger, which only takes less than a minute per battery.
Let the electrolyte reduce in level to the level you thought it was too low
to begin with. This is done by running the EV and charging several times.
The electrolyte should read higher at this lower level, because you have
bubble off the H20.
Charge the battery with this low electrolyte level to about 80% to 90% SOC.
Check the SG and than add the same sg reading to the level which should have
be done in the first initial fill.
If your premix electrolyte is at 1.265 sg, then try to charge your battery
to 1.265 first and than add the electrolyte at that time.
My last pack, which was was about 10 years old, the electrolyte level and SG
may not be equal to the other batteries, so I charge them with a seperated
charger at a rate of 40 to 50 amps.
Today, you can get a 6-12 volt smart charger that can charge 10 to 60 amps
on 120 v at 1 to 6 amps AC. I got my from Wal-Mart which is a solid state
unit that can charge standard, deep cycle, AGM and gel batteries.
Roland
----- Original Message -----
From: "Chuck Hursch" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, October 16, 2006 2:48 AM
Subject: Re: Floodies/Batt. murder mystery/Thanks to Roger & Roland
> Roland,
>
> I was looking at your post of Sept. 29 again. For all that read
> this, remember the 1.75 SG is a typo and should be read as 1.275
> SG.
> >
> > You may have given me a clue, when you said your batteries were
> deliver with
> > low electrolyte.
> >
> > If I remember right, is that the water to acid ratio is about 5
> parts of
> > water to 3 parts of water.
> >
> > Water being 1.0 sg and sulfuric acid is 1.8. Adding 5 (five
> parts of water)
> > to 1.8+1.8+1.8 (three parts of acid) = 10.4
> >
> > Divide 10.4 by eight parts = 1.3 SG electrolyte while its hot.
> When cool
> > down it will be about 1.75 SG.
>
> So here's something basic I'm tripping up on. I assume your 1.3
> SG and 1.275 SG are non temperature compensated. Isn't the hot
> electrolyte less dense, hence shouldn't that have a lower SG
> reading than the cold stuff? If you temperature-compensate the
> readings, then hot and cold no longer really matter, right?
> >
> > If a container (cell) is low with 1.75 SG electrolyte (reading
> 1.75 sg)
> > than adding just water might add another part of water or:
> >
> > (6 x 1.0)+ 3 x 1.8) = 11.4
> >
> > 11.4/9 parts = 1.26 SG while hot and may have reduce it to
> 1.24 when cool.
> >
> > So it took more over charging increase the electrolyte to 1.257
> SG. even
> > though the plates were charge to 100%.
> >
> > If the original reading of the electrolyte was at 1.75 SG and
> you added
> > water which reduce it to 1.24 SG, You may have over charge it
> to raise the
> > SG.
> >
> > If new batteries are low and the factory did not fill the cell
> all the way
> > out, you must add the same SG electrolyte to the proper level.
> >
> > The white floating crystals is the sulfate or SO4 from the
> negative plates,
> > meaning you are releasing the sulfate from the negative plates
> at a too fast
> > of a charge. The sulfate is ejecting from the negative plates
> as particles
> > instead of dissolving very slowly.
>
> Well, my bulk charge rate has been 10-11A on a 235A-hr battery.
> US Battery recommendation as I recall is to charge at C/10, or in
> my case about 23A, so I'm well under. I would charge faster, but
> don't have the charger or AC line to do so. I can get to 15A DC
> into the pack without tripping the 20A circuit breaker in my
> apartment, but to run it at this rate is unsafe, as I'm way over
> the NEC 80% limit (16A).
> >
> [snip]
> > The problem now, is to find out what the real charge rating of
> the plates
> > are at. They may no longer correspond to the SG of the diluted
> acid.
> >
> > One way that might work, is to let the electrolyte level get
> down to the
> > level you thought was low. Charge the batteries at a low rate
> as to not to
> > eject more material as high SG you can go.Read the SG which
> should be higher
> > now, because there is less water by removing 1 part.
>
> So should I charge at something like 2A? That is, do a discharge
> of some (?) depth, then charge real slow. That could take days,
> but maybe a weekend and a day or two could be arranged. zzz...
> >
> > Then finish adding electrolyte as should have been done in the
> beginning.
> >
> > This is going to be better than nothing. It may not work, but
> I would give
> > it a try.
> >
> Chuck
>
>
--- End Message ---
--- Begin Message ---
I know that many of you have been doing this for a very long time, and so
much of this is second nature to you.
But some of us aren't as schooled in the electronics, or even the concept of
an EV as you.
My request is that when an idea or question is presented that immediately
sets off your BS detectors or that you may be tempted to immediately
dismiss, can you please explain why. Can you give even the simplest
explanation of why something may be unrealistic or unworkable so that we
newbies and those of use with lofty goals can understand why we are being
dismissed or ridiculed?
I think it's a fair request, and many of you live up to that. But without
naming any names, some on the list such as Death to All Spammers (oops, it
slipped) really leave a bad feeling in this regard.
Thank you.
--- End Message ---
--- Begin Message ---
That could be true, but since a BMS is not in vogue yet, I would just
build them myself. Or like many prefer, send them the kit. Although my
kits tend to be surface mount, but don't have to be if there is enough
initial volume.
Do you use aassembly houses yourself Victor?
Mike
--- In [EMAIL PROTECTED], Victor Tikhonov <[EMAIL PROTECTED]> wrote:
>
> That's what PCB assembly houses are for. One off proto is OK
> for them too.
>
> Victor
>
> Mike Phillips wrote:
> > Exactly.
> >
> > Although soldering skills are not as prevalent as you might think.
> >
> > Mike
> >
> >
> >
> > --- In [EMAIL PROTECTED], Victor Tikhonov <ev@> wrote:
> >> Mike Phillips wrote:
> >>> Building a BMS is a piece of cake.
> >> If you mean stuffing pre-fabricated for you PCBs and load
> >> pre-written software, then sure. If you're patient enough
> >> you can train monkey to stuff your PCBs...
> >>
> >> Victor
> >>
> >
> >
> >
> >
>
--- End Message ---
--- Begin Message ---
Any data available on this?
Mike
--- In [EMAIL PROTECTED], "Osmo S." <[EMAIL PROTECTED]> wrote:
>
> "Nanopollution is a generic name for all waste generated by
> nanodevices or during the nanomaterials manufacturing process. This
> kind of waste may be very dangerous because its size. It can float in
> air the and might easily penetrate animal and plant cells causing
> unknown effects. Most human made nanoparticles do not appear in
> nature so living organism may not have appropriate means to deal with
> this kind of waste. It is probably one great challenge to
> nanotechnology: How to deal with its nanopollutants and nanowaste."
>
> What´s your opinion about this. Should we take it into account when
> considering A123s and other nanotechnology batteries?
>
> I suppose there just isn´t enough information available about this
> issue yet. I sent a question to the A123 manufacturer, but no reply
> (although I think they don´t answer mails sent by individuals anyway).
>
> Osmo
>
--- End Message ---
--- Begin Message ---
So you think this an matter of manufacturing process only, and those
nanoparticles are not a risk when using/abusing/crashing or recycling
batteries?
I suppose I should read more closely about the technology they use to
make A123s, maybe there would be answers to my questions...
Osmo
Mark McCurdy kirjoitti 16.10.2006 kello 16.04:
Most of those technologies require clean rooms, with air control
systems. Would be very easy to control those micro particles.
Keep the room under negative pressure and the exhaust running
through a furnace. The negative pressure would keep particles from
escaping and the furnace would burn the particles instantly,
turning them into either metal vapor (which would laminate the
exhaust path when it cooled) or turn it into soot.
----- Original Message ----- From: "Osmo S." <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, October 16, 2006 5:11 AM
Subject: A123 & nanopollution
"Nanopollution is a generic name for all waste generated by
nanodevices or during the nanomaterials manufacturing process. This
kind of waste may be very dangerous because its size. It can float in
air the and might easily penetrate animal and plant cells causing
unknown effects. Most human made nanoparticles do not appear in
nature so living organism may not have appropriate means to deal with
this kind of waste. It is probably one great challenge to
nanotechnology: How to deal with its nanopollutants and nanowaste."
What´s your opinion about this. Should we take it into account when
considering A123s and other nanotechnology batteries?
I suppose there just isn´t enough information available about this
issue yet. I sent a question to the A123 manufacturer, but no reply
(although I think they don´t answer mails sent by individuals anyway).
Osmo
--- End Message ---
--- Begin Message ---
On 16 Oct 2006 at 7:49, Phil Marino wrote:
> So, each pair of paralleled batteries is called a "module"?
No, a module is another name for what most people call a battery. It's the
smallest replaceable element in the battery, or what most people call the
"pack." Clear? ;-)
> That's the same
> as what people mean by "buddy pair", right?
"Buddy pairs" are usually paralleled modules (batteries). The pairs are
then connected in series. But it's essentially similar.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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