EV Digest 2587
Topics covered in this issue include:
1) Re: Money talk (was: General Battery Concensus)
by "Bob Rice" <[EMAIL PROTECTED]>
2) Re: High Voltag Contactors
by [EMAIL PROTECTED]
3) Re: Propulse
by [EMAIL PROTECTED]
4) Re: Money talk (was: General Battery Concensus)
by [EMAIL PROTECTED]
5) Re: Best source for Optimas?
by Mark Farver <[EMAIL PROTECTED]>
6) Re:Charging safety was Recipe for battricide?
by Jon Knepher <[EMAIL PROTECTED]>
7) Re: Money talk (was: General Battery Concensus)
by Victor Tikhonov <[EMAIL PROTECTED]>
8) ah o Melted battery top.
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
9) Re: Money talk (was: General Battery Concensus)
by Victor Tikhonov <[EMAIL PROTECTED]>
10) Re: Money talk (was: General Battery Concensus)
by Victor Tikhonov <[EMAIL PROTECTED]>
11) EV For Sale
by [EMAIL PROTECTED]
12) Anti-SUV Rant
by "Thomas Shay" <[EMAIL PROTECTED]>
13) Order NiZn's Now?
by "Dave Stensland" <[EMAIL PROTECTED]>
14) Re: Order NiZn's Now?
by Gordon Niessen <[EMAIL PROTECTED]>
15) Re: Needed South Bay EV1 owners
by "Roy LeMeur" <[EMAIL PROTECTED]>
16) RE: Order NiZn's Now?
by "Myles Twete" <[EMAIL PROTECTED]>
17) Re: Money talk (was: General Battery Concensus)
by "David McAlister" <[EMAIL PROTECTED]>
18) Civic Hybrid Upgrade
by "Christian T. Kocmick" <[EMAIL PROTECTED]>
19) Re:Charging safety was Recipe for battricide?
by "Joe Smalley" <[EMAIL PROTECTED]>
20) Re: Measuring Current
by Ken Lange <[EMAIL PROTECTED]>
21) RE: Money talk (was: General Battery Concensus) - NiMH
by "Mark Fowler" <[EMAIL PROTECTED]>
22) Re: Civic Hybrid Upgrade
by Gordon Niessen <[EMAIL PROTECTED]>
23) Re: Civic Hybrid Upgrade
by "Christopher Zach" <[EMAIL PROTECTED]>
24) Re: Money talk (was: General Battery Concensus)
by Lee Hart <[EMAIL PROTECTED]>
25) Re: Money talk (was: General Battery Concensus)
by Lee Hart <[EMAIL PROTECTED]>
26) Re: Civic Hybrid Upgrade
by Lee Hart <[EMAIL PROTECTED]>
--- Begin Message ---
----- Original Message -----
From: Mark Fowler <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, February 11, 2003 5:27 AM
Subject: RE: Money talk (was: General Battery Concensus)
> I wonder if the price of Li-Ions will ever get NEAR lead acids.
> (sorry)
> Hi All;;
Gees! I hope so, but I wouldn't mind that they are a bunch more, IF
they will give yu the power we have been dreaming of, AND last for ever and
are indifferant to abuse, cold, and an I don't know aditude.Put out
Waylandsque amount of amps, and don't care if and when they get fed again.
No reversed cells and all that stuff. Overcharge the hell out of them, and
they don't care. Yeah, I'm dreaming, but.maybe?
If they do all that, I'll go 10-15K, or more, for a pack that I can pass
on to my kids when I'm too old and feeble to use them mysel;f<g>!
Wouldn't You?
Bob....out of Fantesyland.now
> -----Original Message-----
> From: Mark Fowler
> Sent: Tuesday, 11 February 2003 8:25 PM
> To: [EMAIL PROTECTED]
> Subject: RE: Money talk (was: General Battery Concensus)
>
>
> I too am planning on using Li-Ions.
>
> .. blah blah blah ...
>
> Interesting point - The Thunder-Sky price list quotes about 1/3 the price
per cell for quantities above 10,000 - this pretty blatantly says that if
enough people start using these batteries, they'll get nice and cheap. (Who
knows if they'll ever get new lead acids?)
>
> Mark
>
--- End Message ---
--- Begin Message ---
In a message dated 11/02/03 02:44:51 GMT Standard Time, [EMAIL PROTECTED] writes:
> I believe the Albright contactors are rated for 96 volts so pushing to
> use in 120 V system and certainly no good in a 192 V system.
They used to be rated at 120v, when Albright had test equipment that went
that high. When they updated their equipment it only went to 96v, so that's
what they rate to.
Paul Compton
BVS technical officer www.bvs.org.uk
www.sciroccoev.co.uk
--- End Message ---
--- Begin Message ---
In a message dated 11/02/03 02:56:04 GMT Standard Time,
[EMAIL PROTECTED] writes:
> The Propulse factory is in the former Yugoslavia part of Europe, and has
> been unable to be operated for a while due to the surrounding
"environment".
I understood it was in Slovenia, which was not involved in the troubles. Good
Skiing I hear.
Paul Compton
BVS technical officer www.bvs.org.uk
www.sciroccoev.co.uk
--- End Message ---
--- Begin Message ---
Various people wrote:
> Manufacturer recommends simple CC/CV alg, not even temp compensated.
> Don't ever exceed max voltage, stop accurately, keep cells in balance
> and you're in good shape. PFC-20 can handle it easily. Preferred
> accuracy of the CV portion must be about 1% though.
Don't ever exceed max. voltage PER CELL.
How are you going to keep cells in balance?
> Do these cells need individual cell voltage managers to be operated safely?
Monitoring, both on charge and discharge, as a minimum.
> What happens during the equalisation stage of charging?
There is no equalise phase of charging. Some method of individually finish
charging individual cells must be used to keep cells at the same SOC.
Most laptop LiION battery packs have management chips built in, giving
overvolt per cell, undervolt per cell, overcurrent, and overtemp protection.
They don't however have any means of balancing the cells. I've seen packs
with one essentially flat cell that can by revived by individually charging
the cells.
Paul Compton
BVS technical officer www.bvs.org.uk
www.sciroccoev.co.uk
--- End Message ---
--- Begin Message ---
On Mon, Feb 10, 2003 at 09:47:53PM -0800, John G. Lussmyer wrote:
> At 03:47 PM 2/10/2003 -0800, Alec Proudfoot wrote:
> >Does anyone know the best source for Optimas? Do EAA members get any sort
> >of discount?
>
> Hmm, no answers yet. Weird.
> Anyway, the best price I found was to go to my local Optima dealer. When
> buying 13 of them, I paid $126 ea, included delivery and removal of the old
> batteries.
I purchased 28 for $119 each from my local interstate dealer. What I
discovered was that there are 4 interstate battery dealers in Austin, 3
are standard retail stores, one is hidden back in an industrial park.
Turns out he is mostly a distributor for the retail stores, but had
a storefront and was willing to sell direct. Got them on one pallet,
fresh from the factory (less 2wks old)
Calling everyone within a good driving distance is a good idea. Let
them know how many you want to buy up front. If you can gather a few
other EVers in together, even better.
As another note when I talked to Johnson Battery systems a year ago they
were willing to ship to individuals if you'd buy a entire pallet. (56
YTs per pallet IIRC)
Mark
--
"The greatest dangers to liberty lurk in insidious encroachment by men of
zeal, well-meaning but without understanding."
-- Justice Louis O. Brandeis, Olmstead vs. United States
--- End Message ---
--- Begin Message ---
http://www.wild-e.com/avcon-mod.png
There is no connection to the Y line before the big relay; so there can't be
continuity when the relay is open...
There is probably a way to fool it into being unsafe; let me know. :)
Jon
> ----- Message from [EMAIL PROTECTED] ---------
> Date: Tue, 11 Feb 2003 00:07:51 -0800
> From: Joe Smalley <[EMAIL PROTECTED]>
> Reply-To: [EMAIL PROTECTED]
> Subject: Re:Charging safety was Recipe for battricide?
> To: [EMAIL PROTECTED]
>
> Jon,
>
> Can you convert that schematic to an image and post it, either to me off
> list or to a website and then post the link. I am interested in how it
> works.
>
> Joe Smalley
> Rural Kitsap County WA
> Fiesta 48 volts
> NEDRA 48 volt street conversion record holder
> [EMAIL PROTECTED]
>
>
* LP8.2: HTML/Attachments detected, removed from message *
--- End Message ---
--- Begin Message ---
Joe Smalley wrote:
>
> The design voltage regulation was 0.1% of 400 volts (0.4 volts). If the pack
> is over 40 volts then the charge setpoint should be within 1%.
>
> My concern is the difference between the pack voltage and the cell voltage.
> Even if the pack voltage is regulated to within 0.1%, the cell voltages
> might vary by more than 1%.
>
> Do these cells need individual cell voltage managers to be operated safely?
>
> Joe Smalley
> Rural Kitsap County WA
> Fiesta 48 volts
> NEDRA 48 volt street conversion record holder
> [EMAIL PROTECTED]
They do, but only for limiting max voltage at the end of charge.
Lithium based electrolyte (not LiP cells) will decompose at about 5.2V
so 4.2V is common standard to limit the voltage.
You can get away without BMS at all if you're willing not to use
full capacity and routinely undercharge, say to 3.9V or 4.0V per cell.
If initially cells were balanced, it will take long time to get
them out of balance far enough so that with average 3.9V/cell one
will be > 4.2V. You manually balance every half year or so.
Routine undercharge won't hurt it as PbA, it's just like underfilled
gasoline tank - you won't go as far as with full tank, but it doesn't
hurt a car in any way.
If you want to charge completely, BMS is mandatory. Manufacturer
specifically prohibits charging cells in series unless means to
restrict individual cell voltages to 4.2V are implemented.
BMS does allow much more functionality than just clamping
max voltage. If it was so easy, powerful 4.2V zener across
(may be with an amp to reduce dynamic resistance) would be
about all you need.
Victor
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--- Begin Message ---
I was wondering why one of my batteries was registering a little low on
charge. It seems that one of the external loads melted the plastic it was
on and as well melted into one of my Delphi batteries. Yikes. Seems to
register the same voltage as other batteries around it off charge. Hope
it's a coincidence. Those Mark ones can burn off a lot of heat. Since I
turned down the voltage it's not melting plastic anymore. Lawrence
Rhodes.....
--- End Message ---
--- Begin Message ---
[EMAIL PROTECTED] wrote:
>
> Various people wrote:
That was me :-)
> > Manufacturer recommends simple CC/CV alg, not even temp compensated.
> > Don't ever exceed max voltage, stop accurately, keep cells in balance
^^^^^^^^^^^^^^^^^^^^^
> > and you're in good shape. PFC-20 can handle it easily. Preferred
> > accuracy of the CV portion must be about 1% though.
>
> Don't ever exceed max. voltage PER CELL.
That's what underlined statement refers to.
> How are you going to keep cells in balance?
By individually monitoring each, compare to average of the pack and
boost or drain depending on how far it deviates from that average.
> > Do these cells need individual cell voltage managers to be operated safely?
>
> Monitoring, both on charge and discharge, as a minimum.
What is it so magic about LiIon cells that scare people so much?
I think it's lust a fear of unknown. THe chemistry is rather simple,
certainly no more complex than PbA batteries, just different chemicals
and of course different reaction type.
Have you used them in the vehicle? Monitoring on discharge is
to satisfy your curiosity and to spot any problems with defective
cell or interconnect. It doesn't do anything TO the pack, it
gives YOU info something should be done. Sort of "idiot light".
On charge, keep each cell below max and you're fine. If you
will use Rudman Reg style limiter, once the cells are balanced
(and none are defective) it will take long time to get them
out of balance, provided you keep them at the same temp.
Self discharge is very low, a few mA for 100Ah cell, it will take
years for just stored or equally used batteries to drift out of
balance. I'm not suggesting to count on it, I'm reporting what
the guys running them in a real vehicle experience.
> > What happens during the equalisation stage of charging?
>
> There is no equalise phase of charging. Some method of individually finish
> charging individual cells must be used to keep cells at the same SOC.
This is not accurate. You don't need to finish charge (to 100% SOC)
to keep the cells in balance. In fact, if you deliberately don't charge
to 100% SOC you don't need to keep them in balance at all. There is no
Peukert effect. If one cell is put in service at 90% SOC and
the other cell at 85% SOC, emptying both may leave first at 50% and
second at 45%. Charging back just brings them to 90% and 85%
respectively again (or whatever level), and so on. You can use them
their entire life with this 5% delta. Only if you approach 100%, you
have to be *very* careful and individually take care of them.
In that sense LiIons are more forgiving that PbA - if they are
[reasonably little] out of balance, it doesn't get progressively
worse, delta just stay with them until optionally taken care of.
Again, I'm not suggesting doing this, I'm describing its
properties. It's up to a user, user just have to be educated.
> Most laptop LiION battery packs have management chips built in, giving
> overvolt per cell, undervolt per cell, overcurrent, and overtemp protection.
> They don't however have any means of balancing the cells. I've seen packs
> with one essentially flat cell that can by revived by individually charging
> the cells.
Right. Most laptop packs are sealed, have no vent caps and subject to
uneven heating by the rest of laptop. Laptop packs have all these
protections because people who don't care about them must use them.
Sort of what we want in mass produced EVs.
> Paul Compton
> BVS technical officer www.bvs.org.uk
> www.sciroccoev.co.uk
Victor
--- End Message ---
--- Begin Message ---
Oh boy, did I cause too much ripple...
What a magic word: money. I get bunch of responses on and off list :-D
Chris Weaver wrote:
>
> Your cost-effectiveness analysis intrigues me. Do these perform much
> better in your performance simulations? If you are thinking about a group
> order, let me know (although it may be a little while before I'm ready for
> them - I haven't even decided on a motor yet :)
> Thanks,
> Chris
I believe, analysis is valid, but the conditions were taken
the worst for Optimas - I assume you must travel so far that
must discharge to 80% SOC. Granted, if you limit your range
YT will last longer, but so are LiIons. Therefore if your
daily range is 5 miles, the difference may not be so drastic,
however relationship holds.
All,
Let's re-visit group purchase subject shortly after April 15, shell we?
Would that make more sense? I will ask on the list at that time again,
and by then those brave ones should make up their minds. It's only
2 month away.
Victor
--- End Message ---
--- Begin Message ---
For Sale: All Electric 1992 Saturn SL2
Formerly the Chico State Advanced Vehicle Research and Development (AVR&D)
Project Vehicle
anyone who might be interested in purchasing Chico State's EV, formerly a
hybrid.
The Chico State AVR&D Vehicle - the second Saturn SL2 converted to all
electric power by Chico State engineering and technology students - is being
sold. The 1992 Saturn SL2 was purchased in 1995 and was converted to an
all-electric drive system, powered by an AC Propulsion Electric Motor and
Controller with regenerative braking and hybrid connectivity. The motor and
controller are designed to work with an optional auxiliary power source -
such as a gasoline engine - in a hybrid mode. The motor and controller are
currently powered by 26 deep-cycle lead-acid batteries. The battery pack
can be charged by connection to 110 and 220 volt household current. The
vehicle has been driven only for testing and demonstration purposes in the
past several years and has been garaged since its initial conversion. The
chassis and interior are in excellent condition. The current range is
somewhat limited by the state of the current battery pack which needs some
attention. When supplemented with a gasoline engine auxiliary power unit,
the vehicle is capable of extended range travel as batteries are recharged
while driving by a gasoline engine. This vehicle is completely street legal
with standard safety features and is perfect car for the hobbyist or student
of ultra-low emission vehicle technology.
Bids for the vehicle purchase, as is, will be accepted through February
28th, 2003. Bidding begins at $12,000.
For information or bidding please contact
Dr. Michael Ward, Associate Dean
College of Engineering, Computer Science, and Technology
California State University, Chico
Email: [EMAIL PROTECTED]
Phone: 530-898-4888
--- End Message ---
--- Begin Message ---
Those who enjoy reading rants about SUVs should enjoy this one:
http://www.sfgate.com/cgi-bin/article.cgi?file=/gate/archive/2003/01/15/note
s011503.DTL
--- End Message ---
--- Begin Message ---
I ran across this online and thought it might be of interest...
"Three Circles Battery Intros M100-12 NiZn Battery
January 28, 2003
Three Circles ERC Battery Co. Ltd. (China) announced its new M100-12
rechargeable nickel-zinc battery, which measures 366mm x 175mm x 225mm;
weighs 23kg; and is designed for use in electric wheelchairs, scooters
and other electric vehicles.
Available with a sealed construction, the company claims that the
battery is non-spillable and is maintenance-free. The battery has a
nominal voltage of 12V and a capacity of 85Ah. The M100-12 has a cycle
life of >500 charging cycles and requires a charging time of 3.5h. The
battery is screened for operation over the -10�C to +50�C temperature
range."
Source: http://www.powerpulse.net/cgi-bin/displayprod_new.pl?id=7813
Interested yet? Good. Let's get to the good stuff. A Google lookup on
Three Circles Battery found their website. It's a flash intro... if you
don't like flash don't click this... http://www.xmerc.com It looks like
the company is entertaining quotes for quantity battery purchases.
Here's a direct link to their product line...
http://www.xmerc.com/eng/INFO_01.ASP
Hope this helps someone... I've only put 40 cycles on my T-105s so far!
-Dave Stensland
Mead, Colorado
--- End Message ---
--- Begin Message ---
Isn't that the company that Evercel had as a partner? Must be just a
international marketing difference.
From the look of the performance graphs, the batteries do suffer when the
discharge rate is high.
At 05:46 PM 2/11/2003, you wrote:
I ran across this online and thought it might be of interest...
"Three Circles Battery Intros M100-12 NiZn Battery
January 28, 2003
Three Circles ERC Battery Co. Ltd. (China) announced its new M100-12
rechargeable nickel-zinc battery, which measures 366mm x 175mm x 225mm;
weighs 23kg; and is designed for use in electric wheelchairs, scooters
and other electric vehicles.
Available with a sealed construction, the company claims that the
battery is non-spillable and is maintenance-free. The battery has a
nominal voltage of 12V and a capacity of 85Ah. The M100-12 has a cycle
life of >500 charging cycles and requires a charging time of 3.5h. The
battery is screened for operation over the -10�C to +50�C temperature
range."
Source: http://www.powerpulse.net/cgi-bin/displayprod_new.pl?id=7813
Interested yet? Good. Let's get to the good stuff. A Google lookup on
Three Circles Battery found their website. It's a flash intro... if you
don't like flash don't click this... http://www.xmerc.com It looks like
the company is entertaining quotes for quantity battery purchases.
Here's a direct link to their product line...
http://www.xmerc.com/eng/INFO_01.ASP
Hope this helps someone... I've only put 40 cycles on my T-105s so far!
-Dave Stensland
Mead, Colorado
--- End Message ---
--- Begin Message ---
Unfortunately, you won't find an EV1 "owner" in the South Bay or anywhere
else. They were only available to lease (if you were lucky and lived in the
right city and were willing to jump through lots of hoops and wait for a
long time).
GM will not sell you one for any price and virtually "all" are due to be
crushed.
----------------------
I'm looking for South Bay EV1 owners who want to discuss the demise
of the vehicle for an article in a local newspaper. Preferably,
people should live somewhere in between Westchester and San Pedro in
the South Bay of Los Angeles. (I'm hoping it will run this weekend)
Thanks.
Roy LeMeur Seattle WA
My Electric Vehicle Pages:
http://www.angelfire.com/ca4/renewables/evpage.html
Informational Electric Vehicle Links:
http://www.angelfire.com/ca4/renewables/evlinks.html
_________________________________________________________________
MSN 8 with e-mail virus protection service: 2 months FREE*
http://join.msn.com/?page=features/virus
--- End Message ---
--- Begin Message ---
So where can we get NiZn 12v/85Ah batteries now and what will we have to
pay?
My only discovery was Cabellas which wants $300 each or so...at that rate,
make mine LiPolyIon.
-Myles Twete
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On
Behalf Of Gordon Niessen
Sent: Tuesday, February 11, 2003 5:35 PM
To: [EMAIL PROTECTED]
Subject: Re: Order NiZn's Now?
Isn't that the company that Evercel had as a partner? Must be just a
international marketing difference.
From the look of the performance graphs, the batteries do suffer when the
discharge rate is high.
At 05:46 PM 2/11/2003, you wrote:
>I ran across this online and thought it might be of interest...
>
>"Three Circles Battery Intros M100-12 NiZn Battery
>January 28, 2003
>
>Three Circles ERC Battery Co. Ltd. (China) announced its new M100-12
>rechargeable nickel-zinc battery, which measures 366mm x 175mm x 225mm;
>weighs 23kg; and is designed for use in electric wheelchairs, scooters
>and other electric vehicles.
>
>Available with a sealed construction, the company claims that the
>battery is non-spillable and is maintenance-free. The battery has a
>nominal voltage of 12V and a capacity of 85Ah. The M100-12 has a cycle
>life of >500 charging cycles and requires a charging time of 3.5h. The
>battery is screened for operation over the -10�C to +50�C temperature
>range."
>Source: http://www.powerpulse.net/cgi-bin/displayprod_new.pl?id=7813
>
>Interested yet? Good. Let's get to the good stuff. A Google lookup on
>Three Circles Battery found their website. It's a flash intro... if you
>don't like flash don't click this... http://www.xmerc.com It looks like
>the company is entertaining quotes for quantity battery purchases.
>Here's a direct link to their product line...
>http://www.xmerc.com/eng/INFO_01.ASP
>
>Hope this helps someone... I've only put 40 cycles on my T-105s so far!
>
>-Dave Stensland
>Mead, Colorado
--- End Message ---
--- Begin Message ---
Danger, second hand information ahead!!!!!
I am working on a machine for Texaco Ovonics. I was talking to one of their
engineers recently about battery technologies, particularly their
competition. He said Li-X was not competition as scaling up from laptop
size cells and batteries to EV size was difficult. Another problem is
production yield. Many units off the assembly line are scrap. Maybe
ThunderSky has found a way around this or maybe the opinions of Ovonics
about their competition is tainted.
BTW, Ovonics is planning to make a bunch of NiMH!!
----- Original Message -----
From: "Mark Fowler" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, February 11, 2003 3:25 AM
Subject: RE: Money talk (was: General Battery Concensus)
> I too am planning on using Li-Ions.
>
> The only tricky bit I see is there is not a lot of info about how
electrically robust these batteries are.
>
> Things like:
> How much does it impact the long term life of the batteries to draw large
current from them (>3C)?
> What happens during the equalisation stage of charging?
> Will these batteries need regulators to prevent overcharging during
equalisation?
> What options are available as far as BMS is concerned?
> How well will they perform after 5 years of typical EV use?
>
> There's a huge amount of experience and knowledge on this list about these
things and lead acid batteries, but not much about other chemistries.
>
> I guess it is up to people like Victor (Li-Ion) and Joe (Evercell) to try
these things out and see how they go - and let us know what they think so we
can make informed decisions.
>
> Hey Victor - have you got to the 500 battery mark yet?
> (For people wanting Li-Ion batts)
>
> Interesting point - The Thunder-Sky price list quotes about 1/3 the price
per cell for quantities above 10,000 - this pretty blatantly says that if
enough people start using these batteries, they'll get nice and cheap. (Who
knows if they'll ever get new lead acids?)
>
> Mark
>
> -----Original Message-----
> From: Victor Tikhonov [mailto:[EMAIL PROTECTED]]
> Sent: Tuesday, 11 February 2003 1:33 PM
> To: [EMAIL PROTECTED]
> Subject: Money talk (was: General Battery Concensus)
>
>
> "John G. Lussmyer" wrote:
> >
> > One thing I've been trying to do while looking at batteries is to look
at
> > $/mi for the pack.
> > This has to take into account:
> > A) Average trip length (i.e. average DOD)
> > B) $ for the pack
> > C) Useful cycle life with the above DOD.
> > Of course the DOD for a given trip changes for each type of battery, so
you
> > can't just use 50% DOD for all battery types.
> > Example: My Sparrow with a 27 mile commute is about a 90% DOD for
Optimas,
> > but would probably only be about a 40% DOD for a LiIon pack.
>
> This is correct; all conditions (range) must be equal to compare
> the pack. The same person/car will go the same distances if the battery
> type will be ever switched, so for a given person it's relevant how
> much he pays for the pack per it's life, which is different because
> of different DODs. You may get surprising results.
>
> Example:
>
> My current pack of 27 Optimas $125 each (not counting mistakes :-) ),
> $3,375. 43 useful Ah * 340V = 14,628 Wh pack. Discharged to 80% DOD
> means 11,703 Wh spent and I can do it 220 (Manufacturer rated) times.
> 11,703 Wh*220=2,574,660 Wh moved over life, and I have to throw away
> the pack. I paid $3,375/2,574,660=$0,0013/Wh or $1.3/kWh over life.
>
> LiIon: 100 cell 100 Ah 3.6V each, 36,000 Wh pack, $15,000.
> Going the same distance as above, requiring 11,703 Wh will bring
> it to just 11,703*100/36,000=32.5% DOD, and my pack then is lasting
> for 3000 cycles at this DOD (estimation, based on Thunder-sky data)
> over life. I move 11,703*3,000=35,109,000 Wh, and throw away the pack.
> I paid $15,000/35109000=$0,000427/Wh or $0,427 per Wh over life.
>
> Conclusions (for my situation only, and I assume BMS cost is about
> the same, $1000 difference won't make any real difference, here
> is why):
>
> 1. LiIon pack end up more than 3 times cheaper than YT Optimas over
> life (provided I keep replacing Optimas during life of LiIons).
>
> 2. Charged once a day optima last for 220 days, 7.3 month.
> LiIon last for 3000 days or 8 years 4 month. During that time
> I'd have to replace 3000/220=13.6 YT packs.
>
> The cost of 13.6 YT packs is $3,375*13.6=$45,900
>
> 4. This all is not to mention a fun light car all these years
> and not having problems with beefing suspension, for PbA,
> handling, braking, etc. Something hard to estimate in dollars,
> but you see a big picture.
>
> The only turn off is large up front investment. But it's
> like a mortgage if you don't buy your house outright.
> Few can, but in case of batteries shelling out $15k
> I can survive (worst case - take a loan).
>
> So you decide whether you want to pay $15k one time or
> spread about $46k over 8 years in $3,375 portions every
> 7.3 month. Don't forget, you provide pack replacement
> free fun labor too, 13 times. Don't know about you guys,
> but I'm fed up after my 3rd pack replacement...
>
> Disclaimer: check my math.
> Statement: I'll do LiIon regardless of my math :-)
>
> Victor
>
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Where does the AVCON logic get its power? Which lines from the left?
Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
----- Original Message -----
From: "Jon Knepher" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>; "Joe Smalley" <[EMAIL PROTECTED]>
Sent: Tuesday, February 11, 2003 12:57 PM
Subject: Re:Charging safety was Recipe for battricide?
>
> http://www.wild-e.com/avcon-mod.png
>
> There is no connection to the Y line before the big relay; so there can't
be
> continuity when the relay is open...
>
> There is probably a way to fool it into being unsafe; let me know. :)
>
> Jon
>
>
> > ----- Message from [EMAIL PROTECTED] ---------
> > Date: Tue, 11 Feb 2003 00:07:51 -0800
> > From: Joe Smalley <[EMAIL PROTECTED]>
> > Reply-To: [EMAIL PROTECTED]
> > Subject: Re:Charging safety was Recipe for battricide?
> > To: [EMAIL PROTECTED]
> >
> > Jon,
> >
> > Can you convert that schematic to an image and post it, either to me off
> > list or to a website and then post the link. I am interested in how it
> > works.
> >
> > Joe Smalley
> > Rural Kitsap County WA
> > Fiesta 48 volts
> > NEDRA 48 volt street conversion record holder
> > [EMAIL PROTECTED]
> >
> >
>
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>
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Hi Bill,
I'm having to dig a bit to find some information for you.
>> Where can those Honeywell dc current sensors and electronics be procured?
I put the URL for the sensor I used below. I bought mine at Newark
Electronics,
www.newark.com.
>> How much would they cost ?
I see the price has about doubled since I bought them. They're about
$40 now.
>> How accurate is the equipment ?
Check the spec sheet. Basically the system is within a couple of
percent. This
assumes you've initially adjusted the offset and gain with tweaks.
>> What is the max current this equipment can measure ?
You can buy different ranges, which is what I did so that I'd have
better accuracy
for charging at a maximum of 50 amps, and for driving at a maximum of
600 amps.
There are higher current models.
>> What are the part numbers of thes equipment ?
I used CSLA2EL
>> Sounds like alot lighter then using three large heavy bulky brass
shunts :-).
Yes, they are lighter, but they're not weightless.
I was warned about the lack of accuracy due to offset drift, but this
hasn't been a
problem for me. The largest inaccuracy I saw when I tested them was due to
hysteresis. Even this isn't too bad. If you use them, don't mount them
too close
to a magnet, such as what resides in Kilovac contactors. If you want better
accuracy, you can try the closed-loop sensors, but they need lots of $$$ and
require more serious power as well.
http://catalog.sensing.honeywell.com/datasheet.asp?PN=CSLA2EL&FAM=current&P=8158,21830
I think there are application notes on this site as well.
Hope this helps.
Best regards,
Ken
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The only problem is that Texaco Ovonics won't sell their batteries to people building
just one car - they want (relatively) large scale manufacturers.
(At least that was the story when I asked them late last year)
Similar to all the other non lead acid batteries, NiMH batts store more power in less
volume and weight than lead acid.
(And the 50Ah jobbies from TXOB can pump out 760A according to their specs - it made
me smile)
Mark
-----Original Message-----
From: David McAlister [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, 12 February 2003 2:11 PM
To: [EMAIL PROTECTED]
Subject: Re: Money talk (was: General Battery Concensus)
Danger, second hand information ahead!!!!!
I am working on a machine for Texaco Ovonics. I was talking to one of their
engineers recently about battery technologies, particularly their
competition. He said Li-X was not competition as scaling up from laptop
size cells and batteries to EV size was difficult. Another problem is
production yield. Many units off the assembly line are scrap. Maybe
ThunderSky has found a way around this or maybe the opinions of Ovonics
about their competition is tainted.
BTW, Ovonics is planning to make a bunch of NiMH!!
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Not likely. The battery pack is sized for the demand the Assist Hybrid
system needs. To get an advantage from a larger battery pack you would
have to reprogram the assist algorithm and would probably want to upgrade
the electric motor as well.
You would definitely void your warranty. :-)
At 09:23 PM 2/11/2003, you wrote:
For the electrical engineers, I have a question.
If you were to take the Honda Civic Hybrid's battery pack (1.2v X 120
cells) apart, and upgrade it to "D" size or larger NiMH batteries, would
you see any benefits?
Christian
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Regarding bigger batteries in an Insight.
Another question is "why" do it in the first place. The purpose of the pack
in a Hybrid is to provide power boosts when needed, not carry the entire
load of the car (as say in an electric).
The only reason I could see is if you're so heavy on the gas that you manage
to suck down the current pack to "empty" thus causing performance to fall
low since you're now relying on the engine alone (and part of that is always
used to charge the pack a bit). A larger pack will increase the "lead foot"
time, however it will also take longer to charge back to full.
A larger pack will also increase the car's weight, and you will be dragging
around Nickel that you don't use 99% of the time. Waste of fuel to carry
that added stuff around. Better to size the pack for what it needs to do 99%
of the time.
My dad has an Insight, and he has tried to drain the batteries by
experimental driving like a leadfoot maniac. The only time he has really
been able to drop the pack out of the circuit has been going up mountains at
80+mph in high gear. At that speed, at that incline, with that amount of
wind drag the supplimental electric motor carries the load constantly for
many minutes and the batteries wear down. When this happens, the ICE engine
is left holding the load, is charging the pack, and going up a hill. Speed
will drop to <70mph, you have to downshift to 4k+RPMs, and the car's engine
will be running at full power.
Chris
----- Original Message -----
From: "Gordon Niessen" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, February 12, 2003 8:12 AM
Subject: Re: Civic Hybrid Upgrade
> Not likely. The battery pack is sized for the demand the Assist Hybrid
> system needs. To get an advantage from a larger battery pack you would
> have to reprogram the assist algorithm and would probably want to upgrade
> the electric motor as well.
>
> You would definitely void your warranty. :-)
>
> At 09:23 PM 2/11/2003, you wrote:
> >For the electrical engineers, I have a question.
> >If you were to take the Honda Civic Hybrid's battery pack (1.2v X 120
> >cells) apart, and upgrade it to "D" size or larger NiMH batteries, would
> >you see any benefits?
> >
> >Christian
>
>
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Victor Tikhonov wrote:
> You can get away without BMS at all if you're willing not to use
> full capacity and routinely undercharge, say to 3.9V or 4.0V per cell.
>
> If initially cells were balanced, it will take long time to get
> them out of balance far enough so that with average 3.9V/cell one
> will be > 4.2V. You manually balance every half year or so.
This sounds like a formula for becoming a mass murderer (of batteries,
that is). I've never seen any cells matched so well that will stay in
balance for any significant number of charge-discharge cycles, no matter
what the chemistry. Without a balancing system, they all depend on
deliberate overcharge to bring them back onto balance.
But with lithiums, you just can't do this overcharging. You have to have
individual cell voltage monitoring, and then some means to either charge
or discharge them individually to restore them to balance.
I wouldn't even depend on the manufacturer to know. These batteries
haven't been around long enough for any life tests. They *can't* know
what will happen to the batteries over their life.
Given the cost of these batteries, I'd rather have a balancing system
and not need it, than have none and discover in a year that my expensive
lithium batteries are shot.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
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>> How are you going to keep cells in balance?
Victor Tikhonov wrote:
> By individually monitoring each, compare to average of the pack and
> boost or drain depending on how far it deviates from that average.
That should work. I'd try to get some temperature sensors in there, too.
> What is it so magic about LiIon cells that scare people so much?
> I think it's lust a fear of unknown.
I suppose we all "lust" after the perfect battery. :-)
But to your point, I think there *is* a healthy skepticism about any new
battery. Historically, people introduce new "miracle" batteries all the
time. They always make wild unsubstantiated claims about how great they
are: Higher capacity, lower internal resistance, longer life, easier to
charge, negligible self-discharge, etc.
Over time, people get hold of the batteries and test them in the real
world. The new battery often (but not always) does have some advantages,
though usually not as extravagant as the manufacturer claims. But also
without fail, every single new battery technology is discovered to have
new weaknesses: High price, inconsistent performance, charging
difficulties, temperature problems, leaks, and short life to name a few.
As the new technology matures, people figure out the problems and their
cures, one by one. The battery slowly gets better over time (assuming
there are enough advantages to make it worth pursuing).
To th point here; no one knows what you have to do to make these
Thundersky lithiums last in an EV. It's all (educated) guesswork. You
should only consider these batteries if:
1. You feel lucky, and think that by some miracle this time the battery
salesmen aren't lying.
2. You don't care about cost or life -- you want high performance NOW.
3. You are doing it for research purposes, to advance the state of the
art.
#1 is a terrible reason. The odds are against you.
#2 is justifiable under certain conditions. You might be building an EV
to prove a point, or to win a race, or to get people to buy stock in
your company. You've got the money, and it doesn't matter if the
batteries last.
#3 is a noble goal, but for the research to be valid, you will need
extensive monitoring and control equipment so you *know* what happened
to the batteries during the test.
> You don't need to finish charge (to 100% SOC) to keep the cells in
> balance. In fact, if you deliberately don't charge to 100% SOC you
> don't need to keep them in balance at all.
But, this will limit your range right now. The lowest SOC limits your
range, and the highest SOC limits your charging.
And, it is bound to shorten the life of some cells in the pack. We don't
know what effect SOC has on lithium cell life, but you can't expect that
SOC has *no* effect on life.
> There is no Peukert effect.
That's true. Peukert is just an empirical equation, determined by
testing real lead-acid batteries. But, there is probably a "Tikhonov"
effect (yet to be discovered, but you may be the one!) that defines the
relationship between a lithium cell's capacity and discharge current.
> If one cell is put in service at 90% SOC and the other cell at
> 85% SOC, emptying both may leave first at 50% and second at 45%.
> Charging back just brings them to 90% and 85% respectively again.
That assumes that their charge and discharge efficiency is 100%, and
identical for all cells. I doubt that this is the case. More likely, the
efficiency is something like 90-95% and varies between cells. This is
what leads to progressively worsening balance.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
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>> If you were to take the Honda Civic Hybrid's battery pack
>> (1.2v X 120 cells) apart, and upgrade it to "D" size or larger
>> NiMH batteries, would you see any benefits?
Christopher Zach wrote:
> The only reason I could see is if you're so heavy on the gas that
> you manage to suck down the current pack to "empty" thus causing
> performance to fall low since you're now relying on the engine
> alone
I don't know how the Insight manages its battery, but I suspect that if
you increase the pack's amphour capacity but leave the rest of the car
unmodified, then Christopher Zach is right; there will be no change in
how it drives until you manage to run the pack down.
But, every degree of hybridization is possible, from 99% gas / 1%
electric to 1% gas / 99% electric. You could modify the car's control
systems (with difficulty) for any desired balance between gas and
electric.
The Insight's setup forces the engine to turn to move the car, but it
doesn't have to be using any fuel. Or, it could be running, but using
barely enough fuel to make up for the engine's frictional losses.
Essentially 100% of the motive power could come from the electric motor
and battery. Range and performance would of course be limited, but with
a big enough pack, it could almost function as an electric vehicle.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
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