EV Digest 6951
Topics covered in this issue include:
1) Re: Understanding my motor (ADC L91 & X91 6.7" motors revisited)
by Lee Hart <[EMAIL PROTECTED]>
2) Re: Controller
by Lee Hart <[EMAIL PROTECTED]>
3) Re: Understanding my motor (ADC L91 & X91 6.7" motors revisited)
by Jim Husted <[EMAIL PROTECTED]>
4) Re: Make it
by Cory Cross <[EMAIL PROTECTED]>
5) Re: EVgrin - RAVolt takes first EV trip
by "Rob Hogenmiller" <[EMAIL PROTECTED]>
6) Re: firefly batteries?
by Bruce Weisenberger <[EMAIL PROTECTED]>
7) Re: An Ebay find?
by "Joseph T. " <[EMAIL PROTECTED]>
8) Re: firefly batteries?
by "Joseph T. " <[EMAIL PROTECTED]>
9) Electrical/Mechanical Engineering
by "Joseph T. " <[EMAIL PROTECTED]>
10) AGM vs Gel
by "Tehben Dean" <[EMAIL PROTECTED]>
11) ???kWh EV battery pack
by "Tehben Dean" <[EMAIL PROTECTED]>
12) Re: AGM vs Gel
by "Joe Smalley" <[EMAIL PROTECTED]>
13) Re: AGM vs Gel
by "Joseph T. " <[EMAIL PROTECTED]>
14) Re: ???kWh EV battery pack
by "Joseph T. " <[EMAIL PROTECTED]>
15) Re: Cheap "balancer" for A123 pack
by Bill Dube <[EMAIL PROTECTED]>
16) Re: An Ebay find?
by lyle sloan <[EMAIL PROTECTED]>
17) Re: An Ebay find?
by Danny Miller <[EMAIL PROTECTED]>
18) Re: Make it
by Dan Frederiksen <[EMAIL PROTECTED]>
19) Re: Manly EV's, RE: EV are for girls blog
by "Loni" <[EMAIL PROTECTED]>
20) Re: VOLTS vs AMPS & RE: Make It
by Dan Frederiksen <[EMAIL PROTECTED]>
21) RE: Electrical/Mechanical Engineering
by Mike Willmon <[EMAIL PROTECTED]>
22) Re: AGM vs Gel
by "Peter VanDerWal" <[EMAIL PROTECTED]>
23) RE: ???kWh EV battery pack
by Mike Willmon <[EMAIL PROTECTED]>
24) Where'd all the NEDRA folks go?
by Mike Willmon <[EMAIL PROTECTED]>
25) Latest honoree of the Troy Heagy award, was Re: Make it
by [EMAIL PROTECTED]
--- Begin Message ---
Jeff Major wrote:
Those slots have 2 wires in them, don't they?
I thought it was one, but I'm going by memory. Jim Husted would know.
Jin, you got your "ears" on? Have you seen the internals of an ADC L91
and X91 for comparison?
--
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 ---
Phelps wrote:
Building a fancy mechanical switch... Is that so hard? Maybe...
Maybe not?
You certainly can build mechanical PWM switchers. Commutator are
mechanical switchers, and they obviously work.
The big challenge with a mechanical switcher is to be sure that there is
always a path for the inductive current, to minimize contact arcing.
Electronic controllers use a diode for this. Purely mechanical PWMs,
built in the "good old days" before semiconductors, had to use other
methods.
The classic method is to set up a resonant circuit, with the motor's
inductance and a large capacitor (called a "buffer cap"). The switch is
mechanically resonant at the frequency of this electrically resonant
circuit. The PWM switch closes; the current resonantly goes from 0 to 2x
the desired current, and then resonantly rings back to almost zero
current again. At this instant, the switch opens. There is therefore
minimal arcing at the switch because it opens and closes at zero current.
The off-time between these cycles is varied to control the percent
on-time of the motor.
On the surface of it, it sounds "easy". In practice, the parts are
physically large, the currents are high, and there is a great deal of
finesse required to get it all working right.
--
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 ---
Hey Lee, Jeff
The L91 has just one wire per slot, although there is
a bottom and a top winding, so depending on how you
count it, lol. I've not seen the X91.
Hope this helps 8^)
Jim
____________________________________________________________________________________
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--- End Message ---
--- Begin Message ---
Dan Frederiksen wrote:
I alot of people have claimed that it must be that expensive but I
don't believe they have offered specific reasons why
to sum up:
the electronics parts cost
circuit board
any bussbar
casing, cooling plumbing and prettyfication
assembly/programming
is either of those super expensive in your opinion and if so which and
how much?
I don't consider the design a cost since that's a one off so don't
mention that
Want to pay my design costs then?
do you have any costs to add?
Dan
--- End Message ---
--- Begin Message ---
Congrats on the EV.
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, June 25, 2007 2:32 PM
Subject: EVgrin - RAVolt takes first EV trip
All,
I know the list loves good news: the RAVolt made her maiden voyage
over the weekend!
YouTube: http://www.youtube.com/watch?v=hUv3wZQTcQE
Rob H
RAVolt.com & EValbum 995
--- End Message ---
--- Begin Message ---
Actually the claim is weight reduction due to less
lead being used. So the reduced lead with advanced
grid I hope comes out in a wash to be the same price
as lead presently is. Performance claim is the same as
present lead with less loss lower resistance allowing
for faster charge and discharge. But until they have a
product and or a spec sheet this is all speculation
and a fantasy. Reality will be when you or I can
order a set from Crown or North Star Batteries or you
see them in a tool from Husqvarna like you can with
the A123's presently. Or Get results from people like
Bill Dube or John Wayland who get sponsored to test
these batteries out. Then we will see reality. John
and Rich Rudman have tested a lot of Batteries for us.
If fact some of the batteries issues have been fixed
specifically due to Abuse by John, Rich, or Bill. And
I only mention these 3 guys because they have freely
posted result on this list in the past and I remember
those post. There are probably many more I have not
remembered or who have not posted in the past no
disrespect intended. I am only pointing out that
Firefly while being mentioned on this list has not
made 1 battery available to the EV community at large
yet. And Any claims made have not been proven. We all
wish they would stop playing around and sell a battery
but they have not. If John were to lose 75% of his
battery weight he may have a hard time getting the
wheels to stick. We will see when the Bill Dube loaner
pack get in a couple months. On the other hand if
White Zombie can keep the tires on the road he may be
Disqualified to run on the Drag tracks due to lack of
roll cage and being too fast. That would be a heck of
a note. Run in the Drag strip and be kick off for
going to fast. But we will see in the coming months
what a A123 pack would do for the White Zombie. And if
Crown Ever produces Firefly Batteries then maybe well
see What they can do.
--- [EMAIL PROTECTED] wrote:
> The claims made about the firefly batteries if
> true. Would make them worth
> three times the cost of lead batteries. They would
> be a huge leap in
> performance.
>
> Don Blazer
>
>
> In a message dated 6/25/2007 7:32:41 PM Pacific
> Daylight Time,
> [EMAIL PROTECTED] writes:
> They are designers. From 3 to 30 people in 3 years
> per
> a Peoria Newspaper article linked to their website.
> The are designing the batteries for Husqvarna
> gardening equipment such as weed eaters, lawnmowers.
>
> They are not building product. They are R & D and
> then
> selling the design to the individual manufactures
> to
> build their own batteries. In May 2007 they signed
> a
> manufacturing agreement with Crown Battery In April
> thay signed an agreement with North Star Battery.
> Read the press releases and news articles.
> www.fireflyenergy.com
> With the release to Crown there maybe hope for use
> EV'er to see these batteries in the next year or 2.
> The Weight savings is in the lack of main plates.
> Instead of plates with lead paste spread across
> them
> they use a Carbon Fiber screen. So image a Trojan
> 125
> weighing only 16.5 lbs instead of 66 lbs. On a 72
> Volt
> pack we are talking 200 lbs verse 800 lbs. Or
> imagine
> Johns White Zombie from his roughly 500 lbs
> reduced
> to 125 lbs. John that is only a guest on weight of
> your present pack weight no insult intended. But
> essentially if batteries where a 1/4 of the weight
> where will EV be tomorrow. This is what makes
> Lithium
> batteries so attractive. IF Carbon Fiber plates can
> do
> the same for Lead then So be it. And hopefully at a
> similar price to lead batteries now. I know I'm
> dreaming here.
>
> --- "Joseph T. " <[EMAIL PROTECTED]> wrote:
>
> > I think they saidth that they already do have a
> > battery; they say it's
> > going to be used in real life for some company or
> > something.
> >
> > On 6/25/07, [EMAIL PROTECTED]
> <[EMAIL PROTECTED]>
> > wrote:
> > > Hello Lawrence
> > >
> > > One other difference then regular lead
> batteries.
> > If I remember right they
> > > were to weigh like 1/4 the weight of lead acid
> > batteries.
> > >
> > > I read about these at least 2 or 3 years ago.
> They
> > even had the city they
> > > were in investing money into the new company.
> You
> > would think they would have a
> > > battery out by now?
> > >
> > > Don Blazer
> > >
> > > In a message dated 6/25/2007 2:11:18 PM Pacific
> > Daylight Time,
> > > [EMAIL PROTECTED] writes:
> > > If what they say is true there won't be any
> > difference between them and
> > > regular lead batteries except capacity,
> > durability & reliability. I suspect
> > > they won't even need regulators. Lawrence
> > Rhodes....
> > > ----- Original Message -----
> > > From: "Zeke Yewdall" <[EMAIL PROTECTED]>
> > > To: <ev@listproc.sjsu.edu>
> > > Sent: Sunday, June 24, 2007 8:22 PM
> > > Subject: firefly batteries?
> > >
> > >
> > > > Wondering if anyone has any thoughts on
> these?
> > I sort of have an in
> > > > with the company to test some in my EV
> > (probably about 5 or 10%
> > > > probability, but that's better than no
> > contacts)... but as of yet all
> > > > I've seen is hype, not specs. BMS required?
> > Discharge rate? cycles?
> > > > Thermal management? Not even sure if they
> > really exist yet.... I
> > > > supposed I could ask my contact there, but I
> > figured someone on this
> > > > list might have already researched them more
> > than I have.
> > > >
> > > > Z
> > > >
> > >
> > >
> > >
> > >
> > > ************************************** See
> what's
> > free at http://www.aol.com.
> > >
> > >
> >
> >
>
>
>
>
>
______________________________________________________________________________
> ______
> Looking for a deal? Find great prices on flights
> and hotels with Yahoo!
> FareChase.
> http://farechase.yahoo.com/
>
>
>
>
> ************************************** See what's
> free at http://www.aol.com.
>
>
____________________________________________________________________________________
Looking for a deal? Find great prices on flights and hotels with Yahoo!
FareChase.
http://farechase.yahoo.com/
--- End Message ---
--- Begin Message ---
I can't read what you're saying (go to Gmail where you can choose to
have "plain" text)
but I'll comment about an Chrysler EPIC I saw on ebay with NiMH I
think. Super rare car!
On 6/25/07, Tom Gocze <[EMAIL PROTECTED]> wrote:
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* ---REMAINDER OF MESSAGE TRUNCATED--- *
* This post contains a forbidden message format *
* (such as an attached file, a v-card, HTML formatting) *
* Lists at sjsu.edu only accept PLAIN TEXT *
* If your postings display this message your mail program *
* is not set to send PLAIN TEXT ONLY and needs adjusting *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
----
--- End Message ---
--- Begin Message ---
Ahh...The dream of the miracle battery.
The disapointment of real life...
:)
On 6/25/07, Bruce Weisenberger <[EMAIL PROTECTED]> wrote:
They are designers. From 3 to 30 people in 3 years per
a Peoria Newspaper article linked to their website.
The are designing the batteries for Husqvarna
gardening equipment such as weed eaters, lawnmowers.
They are not building product. They are R & D and then
selling the design to the individual manufactures to
build their own batteries. In May 2007 they signed a
manufacturing agreement with Crown Battery In April
thay signed an agreement with North Star Battery.
Read the press releases and news articles.
www.fireflyenergy.com
With the release to Crown there maybe hope for use
EV'er to see these batteries in the next year or 2.
The Weight savings is in the lack of main plates.
Instead of plates with lead paste spread across them
they use a Carbon Fiber screen. So image a Trojan 125
weighing only 16.5 lbs instead of 66 lbs. On a 72 Volt
pack we are talking 200 lbs verse 800 lbs. Or imagine
Johns White Zombie from his roughly 500 lbs reduced
to 125 lbs. John that is only a guest on weight of
your present pack weight no insult intended. But
essentially if batteries where a 1/4 of the weight
where will EV be tomorrow. This is what makes Lithium
batteries so attractive. IF Carbon Fiber plates can do
the same for Lead then So be it. And hopefully at a
similar price to lead batteries now. I know I'm
dreaming here.
--- "Joseph T. " <[EMAIL PROTECTED]> wrote:
> I think they saidth that they already do have a
> battery; they say it's
> going to be used in real life for some company or
> something.
>
> On 6/25/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]>
> wrote:
> > Hello Lawrence
> >
> > One other difference then regular lead batteries.
> If I remember right they
> > were to weigh like 1/4 the weight of lead acid
> batteries.
> >
> > I read about these at least 2 or 3 years ago. They
> even had the city they
> > were in investing money into the new company. You
> would think they would have a
> > battery out by now?
> >
> > Don Blazer
> >
> > In a message dated 6/25/2007 2:11:18 PM Pacific
> Daylight Time,
> > [EMAIL PROTECTED] writes:
> > If what they say is true there won't be any
> difference between them and
> > regular lead batteries except capacity,
> durability & reliability. I suspect
> > they won't even need regulators. Lawrence
> Rhodes....
> > ----- Original Message -----
> > From: "Zeke Yewdall" <[EMAIL PROTECTED]>
> > To: <ev@listproc.sjsu.edu>
> > Sent: Sunday, June 24, 2007 8:22 PM
> > Subject: firefly batteries?
> >
> >
> > > Wondering if anyone has any thoughts on these?
> I sort of have an in
> > > with the company to test some in my EV
> (probably about 5 or 10%
> > > probability, but that's better than no
> contacts)... but as of yet all
> > > I've seen is hype, not specs. BMS required?
> Discharge rate? cycles?
> > > Thermal management? Not even sure if they
> really exist yet.... I
> > > supposed I could ask my contact there, but I
> figured someone on this
> > > list might have already researched them more
> than I have.
> > >
> > > Z
> > >
> >
> >
> >
> >
> > ************************************** See what's
> free at http://www.aol.com.
> >
> >
>
>
____________________________________________________________________________________
Looking for a deal? Find great prices on flights and hotels with Yahoo!
FareChase.
http://farechase.yahoo.com/
--- End Message ---
--- Begin Message ---
What kind of math is required and, or recommended to become an
electrical or mechanical engineer?
I hear alot people saying that they're engineers here, so this will
determine if it's a bluffing!
--- End Message ---
--- Begin Message ---
What is the difference between Gel and AGM for EV use? Like which
performs better in the cold etc.?... I guess I would like to know what
are the plusses and minuses of each.
I have been reading some about batteries and came across this.
Deka claims this battery -Deka Gel Maintenance Free:
http://www.eastpenn-deka.com/default.aspx?pageid=552
is...
• Designed for either full discharge/recharge or opportunity charge operation.
and...
Will recharge fully after complete discharge when properly charged.†
† Dominator batteries must be charged using East Penn Manufacturing
approved motive power chargers.
They don't have any detailed specs that i can find. I think it is the
same as the Dominator marine battery????
The marine battery says :
■ Faster recharging…
■ Longer life…
■ Recharges to full power, even if left discharged for months.
■ Resists damaging over-discharges
■ Runs considerably longer than comparable wet batteries
My controller has a max current output of 400amps (I will be useing a
300volt pack) would the Deka Dominator gel marine batteries be
suitable?
Thanks,
TEhben
--- End Message ---
--- Begin Message ---
I know higher voltage less capacity and vise versa, but wondered are
there some general kWh sizes that are used for different types of EVs
e.g. pickups etc.?
Or is it get as much as you can fit in without grossly over weighting
the vehicle? :)
(this is assuming Lead batt's)
TEhben
--- End Message ---
--- Begin Message ---
My experience suggests the AGM are better at draws in excess of 1C and the
gel are comparable below C/2 depending on the brand.
Joe Smalley
Rural Kitsap County WA
Former owner of 48 Volt Fiesta
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
----- Original Message -----
From: "Tehben Dean" <[EMAIL PROTECTED]>
To: "evlist" <ev@listproc.sjsu.edu>
Sent: Monday, June 25, 2007 11:09 PM
Subject: AGM vs Gel
What is the difference between Gel and AGM for EV use? Like which
performs better in the cold etc.?... I guess I would like to know what
are the plusses and minuses of each.
I have been reading some about batteries and came across this.
Deka claims this battery -Deka Gel Maintenance Free:
http://www.eastpenn-deka.com/default.aspx?pageid=552
is...
• Designed for either full discharge/recharge or opportunity charge
operation.
and...
Will recharge fully after complete discharge when properly charged.†
† Dominator batteries must be charged using East Penn Manufacturing
approved motive power chargers.
They don't have any detailed specs that i can find. I think it is the
same as the Dominator marine battery????
The marine battery says :
■ Faster recharging…
■ Longer life…
■ Recharges to full power, even if left discharged for months.
■ Resists damaging over-discharges
■ Runs considerably longer than comparable wet batteries
My controller has a max current output of 400amps (I will be useing a
300volt pack) would the Deka Dominator gel marine batteries be
suitable?
Thanks,
TEhben
--- End Message ---
--- Begin Message ---
Deka Gel batteries are more suitable to low-amp application such as
that in AC drive systems. I'm not sure what the difference is b/s gel
and AGM.
On 6/26/07, Tehben Dean <[EMAIL PROTECTED]> wrote:
What is the difference between Gel and AGM for EV use? Like which
performs better in the cold etc.?... I guess I would like to know what
are the plusses and minuses of each.
I have been reading some about batteries and came across this.
Deka claims this battery -Deka Gel Maintenance Free:
http://www.eastpenn-deka.com/default.aspx?pageid=552
is...
• Designed for either full discharge/recharge or opportunity charge operation.
and...
Will recharge fully after complete discharge when properly charged.†
† Dominator batteries must be charged using East Penn Manufacturing
approved motive power chargers.
They don't have any detailed specs that i can find. I think it is the
same as the Dominator marine battery????
The marine battery says :
■ Faster recharging…
■ Longer life…
■ Recharges to full power, even if left discharged for months.
■ Resists damaging over-discharges
■ Runs considerably longer than comparable wet batteries
My controller has a max current output of 400amps (I will be useing a
300volt pack) would the Deka Dominator gel marine batteries be
suitable?
Thanks,
TEhben
--- End Message ---
--- Begin Message ---
Number of Kwh for an EV battery back is often around 15 for lead acid.
On 6/26/07, Tehben Dean <[EMAIL PROTECTED]> wrote:
I know higher voltage less capacity and vise versa, but wondered are
there some general kWh sizes that are used for different types of EVs
e.g. pickups etc.?
Or is it get as much as you can fit in without grossly over weighting
the vehicle? :)
(this is assuming Lead batt's)
TEhben
--- End Message ---
--- Begin Message ---
Lots of questions that have been asked and answered before on this
list. Here are the answers again:
Cycle life = > 10,000 cycles to 90% DOD to 50% remaining capacity.
(1000 to 95% remaining capacity)
Larger cells are going to happen in a year or so. (Small cells
parallel excellently, so I don't get why folks care about this.) The
larger cells are not going to be huge, however. They will be sized
for hybrid and plug-in hybrid use.
The specific energy pretty much scales with voltage. Since the ion
phosphate cells have lower voltage than the specific energy will be
that much less, all else being equal. Though to go against the
physics on that point.
Keep in mind that Alairnano has not released any cells to anyone
outside their direct influence. If you have a hot new battery that
really works well, you want to make engineering development samples
available to all the OEMs. Altairnano has not done this. You do the math. :-)
Bill Dube'
At 04:17 PM 6/25/2007, you wrote:
Ok. Now we are getting there.
LiFe cells have this characteristics. TS has chrome and fluor and
100 times larger particles in the electrodes compared to Mr Goodenoughs stuff.
TS LFPs too act much like A123 and Hydro-Quepec batts. Impurities in
the Chinese processes are not such an issue compared to these
nanocomponent batts. It eats the capabilities but lowers the price.
The ability to remember the previously verified SOH on each cell is
quite essential to achieve good life time balance. For drag racers
it's not perhaps the key element but for consumer who will calculate
as accurately as possible how the investment pays back. It's as
essential as it gets.
Bill, You have your hands in the basket. What kind of large size
cells are coming from A123 ? I'm keenly waiting for a 200 Ah cell
from them to do some comparing. Will they also achieve 10000 cycles
with 90% DOD ?
Something siding this issue. How must you guys see the 10 min
charging thing ? Altairnano is betting on that horse. It seems. A123
on cyclic life. Kokam energy density... Interesting approaches. TS
has just low prices :) Which seems to be one big argument too.
I can see lot's of deals for each. Special solutions requiring just
what they offer.
Just the freaking patent issues takes some time.. (referring to A123
and Goodenough)
-Jukka
Bill Dube kirjoitti:
You can't really balance A123 Systems cells at anything between
about 10% SOC and 90% SOC. The open circuit voltage really does not
change except at the top and bottom of the SOC. The impedance also
does not change enough to sense SOC either.
If you want to balance in the middle of the charge (or at
partial discharge) your BMS must "remember" which cells needed
balancing on the previous cycle.
In reality, the A123 Systems cells are very very very
uniform in capacicty and self-discharge. Thus, you don't need to
do much balancing. Having said that, I should add that you MUST
balance very cell. Otherwise, they will inevitably get out of
balance and you will soon ruin cells.
Bill Dube'
At 01:00 PM 6/24/2007, you wrote:
Balancing only during charging will get the job half way done.
With shunting you'll accumulate quite bad well-to-wheel
efficiency. Also the charging time will be longer.
During discharge balancing is quite useful since you'll get the
most of range out too. And not stressing the weakest link the
most. Also the discharging can be weary process.
With Lions you'll get the range and at least in my drivings it
takes several hours to deplete the batteries. So power is not the
issue with balancing. You have time for the compensation
procedures. Also pre-emptive balancing methods are essential.
Ok. Say you wish the pack to last 50 000 miles. You'll get away
with 200 mile range and 250 cycles. No balancing required. Some
tape, bubble gum and protection circuits will do the job.
So how about if the 3000 cycles could be achieved with the best
BMS ever made? That's with 70% average DOD about 400 000 miles.
Say you invest the 30 000 on the pack with BMS and charger. That's
0,075 USD for a mile !
(20 kWh/100 km assumed as average here)
-Jukka
Tony Hwang kirjoitti:
Yes that would be better to move charge around instead of
shunting, but there's no way to make an active charge shuttling
balancer for "cheap", at least not that I know of.
- Tony
----- Original Message ----
From: "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Sent: Thursday, June 21, 2007 5:39:45 AM
Subject: RE: Cheap "balancer" for A123 pack
Please educate me if I am wrong but I would think that if you want to
balance your batteries you wouldn't want to drain some down to match the
others but charge the low ones to match the others. Using shunt
regulators will waste valuable charging current won't it? I think Lee
Hart makes a battery balancer that takes the current and shunts it
AROUND the battery but does not run it through a resistor.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Marcin Ciosek
Sent: Thursday, June 21, 2007 5:12
To: ev@listproc.sjsu.edu
Subject: Re: Cheap "balancer" for A123 pack
Tony,
recently I bough 1900 LiFP cells (not from A123 but it doesn't matter)
and the voltage difference between highest and lowest value was 7mV !!
Assuming you will start from similar point you balancer will do the
trick as long as zener diodes won't differ too much (usually tolerance
of of shunt voltage is 5%). That's my opinion. I would add a protection
circuit preventing cells from deep discharge.
If you don't need fancy BMS that would cost (for you configuration) 400E
this will work fine.
Marcin
--- End Message ---
--- Begin Message ---
Let me fix that for you Tom. Auction number
300124434584 on http://www.ebay.com
HEY, did you ever get some pics from MT Washington?
As I understand it, the Raven from Corbin made its
debute.
Lyle
--- Tom Gocze wrote:
> This is on Ebay. It is an assortment of EV and
> Hybrid texts put out
> by the SAE in the 1990's
>
>
> http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?
> ViewItem&ih=020&sspagename=STRK%3AMESE%
> 3AIT&viewitem=&item=300124434584&rd=1,1
____________________________________________________________________________________
Now that's room service! Choose from over 150,000 hotels
in 45,000 destinations on Yahoo! Travel to find your fit.
http://farechase.yahoo.com/promo-generic-14795097
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Oh yeah!
http://cgi.ebay.com/ebaymotors/Dodge-Caravan-NiMH-EV-Chrysler-EPIC-Electric-Vehicle-Rare-Collectors_W0QQcmdZViewItemQQcategoryZ6193QQihZ014QQitemZ330136589927QQrdZ1QQsspagenameZWDVW
Wow I hadn't even heard of that one.
80 mile range. There are only 14 hrs left and it's only up to $15k!
Danny
Joseph T. wrote:
I can't read what you're saying (go to Gmail where you can choose to
have "plain" text)
but I'll comment about an Chrysler EPIC I saw on ebay with NiMH I
think. Super rare car!
On 6/25/07, Tom Gocze <[EMAIL PROTECTED]> wrote:
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Cory Cross wrote:
Want to pay my design costs then?
I was counting on a few good people offering a bit of their time to help
save the world. I will be one. you might not be
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Thank you Peter. This is the kind of feedback I need. There's such an
overabundance of information to sift through in the EV universe that I
hadn't fully realized how much improved controller technology in conjunction
with high voltage can make a difference to a clean-sheet design. I'm
certainly not stuck on the idea of multiple gear ratios per se, but if you
were limited to, say, 120 volts from your pack (because range and packaging
are both important considerations) and you knew torque with the motor you've
chosen was going to begin falling off at 3500 rpm, how would you address the
issue? Of course I'd love to just dump in more voltage or current, but
design constraints won't allow it. Will changing gears allow me to stay in
the fat part of the motor's torque curve while continuing to accelerate to
max speed, or should I just wring the motor out and accept whatever output
it's capable of as current demand outstrips pack capacity?
----- Original Message -----
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, June 25, 2007 9:23 PM
Subject: Re: Manly EV's, RE: EV are for girls blog
matter. My point was that even robust motors like the ones graphed on the
linked spreadsheet have sweet spot (shaft speed) beyond which torque
falls
off and drawing additional current to sustain torque exceeds safe
continuous
duty parameters.
No, wrong. The torque falls off because there isn't sufficient voltage
from the pack to push the high current anymore. The current is falling
off and because of that so does the torque.
If you raised the voltage, you could continue to apply the same current
and get the same torque, however the fall off point is usually near the
maximum RPM limits for the motor anyway, and there is very little point in
being able to apply maximum torque while the motor is tearing itself apart
from centrifugal force.
With I.C. engines, variable timing now allows for very
flat
torque curves throughout most of the usable rev range (1500-6500rpm), and
of
course they use gears or CVTs to keep them in that range. Agreed?
Not really, the torque is nowhere near as flat as it is with electric
motors and you still can't get torque from an ICE at zero rpm.
With the right controller and battery package you can get perfectly flat
maximum torque from zero RPM all the way to redline on an electric motor.
Trust me, very flat for ICE..... ;-).
As you say, "with the right controller and battery package"... and therin
lies the rub. In a motorscooter or motorcycle using current battery and
motor tech, compromise is required (and maybe more than one gear ratio?).
Your thoughts?
Lon Hull,
Portland, OR
Yes, multiple gears and or a CVT is essential for an ICE. It isn't not
essential for an electric motor. Infact none of the recent production EVs
used a multispeed gearbox or CVT, they simply used a single ratio
reduction and let the motor and controller handle the various torque/RPM
as needed.
With the electric motors typically used in conversions, a multispeed
transmission is usefull, but a CVT would waste more energy than it would
improve the performance of the motor and this is why very few people use
them.
At any rate this is all beside the point Your design goals for your
motorcycle are not practical with todays technology, at least not until
Lithium based batteries get a bit cheaper.
100 mph on a motorcycle takes a tremendous amount of power, getting over
30 miles of range requires a lot of energy. Getting a battery that can
support both of these goals in a small enough package to fit on a
motorcycle is very tough.
Plenty of electric motors can do that, umm the Solectria and Seimens
motors come to mind.
Indeed, have a look at this spreadsheet. It plots torque curves for
various Seimens motors with various battery voltages.
http://www.metricmind.com/data/performance.zip
Note, this doesn't work with openoffice, but did when I tried the real
Excel.
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Lee, many keep saying that it's so impossible.
what is so time consuming about assembling it? where is the great
difficulty that ensures it will cost more?
please try to be specific, not just the 'try it, you will fail' mantra
why will it fail
Dan
Lee Hart wrote:
I'm a good engineer, and a pretty good technician. I *have* built
products of this sort. In my experience, it is impossible to build
your own Curtis controller for less money than Curtis charges, unless
you place no value on your time, your tools, and your training.
If you think you can do it, be my guest! Give it a try! Even if you
fail, you will have learned a lot. We'll talk more when you've finished.
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Well since Maxwell based his equations on the most closely related forms in
fluid dynamics I would think Fluids guys could have an
easy time, but then again I'm not a fluids guy. Knowing this gives new meaning
to the term "waterpipe theory of electronics"
though ;-) But back to your question. I think a good foundation in Algebra,
Trigonometry and Calculus is a good start for a lot
of the physics type work and Differential Equations (Especially DiffEq),
Multivariable Calculus and Probability & Statistics to
support the electrical theory will give a person a good base. To be frank
though you absolutely need those for the more advanced
courses which get you into design work such as Linear Circuits, Automatic
Controls, Filter Design, Digital Systems Design and
Semiconductor Physics. I cannot speak for the Mechanical Engineers, however I
would venture to guess that the same basic math
applies. I wound up taking minor courses in Statics & Strength of Materials,
Dynamics, Thermodynamics and Fluids and I can say
that in those subjects, the same base in math is required, although I found
that the Electrical Engineering courses required more
intimate knowledge of these math concepts.
Mike,
Anchorage, Ak.
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Behalf Of Joseph T.
> Sent: Monday, June 25, 2007 10:07 PM
> To: ev@listproc.sjsu.edu
> Subject: Electrical/Mechanical Engineering
>
>
> What kind of math is required and, or recommended to become an
> electrical or mechanical engineer?
>
> I hear alot people saying that they're engineers here, so this will
> determine if it's a bluffing!
>
>
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The main problem with Gel is that they usually can't handle high current
draws. This has to do with the gel and how slowly the acid moves through
the gel. Very few people use gel cells.
They do tend to be a bit more forgiving than AGMs as far as charging is
concerned and I've heard that they can survive without any kind of
ballancing.
AGMs usually need some for of battery ballancers to keep them equalized,
however they typically can handle HUGE currents.
AGMs perform better in the cold than any of the other lead-acid batteries,
but they still suffer in the cold.
The Deka Dominators can have impressively long shelf life and, if you keep
the discharge currents low, fairly long useful life.
However, they can't handle more than 300amps, maybe 400 amps but that is
pushing it. If you want them to survive for long, you need to keep the
current down to 200-250 amps max.
If you can turn the current down to maybe 300 amps max, then the Deka's
should work OK.
AGMs like Yellow Tops can handle over 1,000 amps and shrug off 600-800 Amp
discharges. AGMs are the battery of choice for those interested in high
performance.
> What is the difference between Gel and AGM for EV use? Like which
> performs better in the cold etc.?... I guess I would like to know what
> are the plusses and minuses of each.
>
> I have been reading some about batteries and came across this.
>
> Deka claims this battery -Deka Gel Maintenance Free:
> http://www.eastpenn-deka.com/default.aspx?pageid=552
> is...
> ⢠Designed for either full discharge/recharge or opportunity charge
> operation.
> and...
> Will recharge fully after complete discharge when properly charged.â
> â Dominator batteries must be charged using East Penn Manufacturing
> approved motive power chargers.
>
> They don't have any detailed specs that i can find. I think it is the
> same as the Dominator marine battery????
> The marine battery says :
> â Faster rechargingâ¦
> â Longer lifeâ¦
> â Recharges to full power, even if left discharged for months.
> â Resists damaging over-discharges
> â Runs considerably longer than comparable wet batteries
>
> My controller has a max current output of 400amps (I will be useing a
> 300volt pack) would the Deka Dominator gel marine batteries be
> suitable?
>
> Thanks,
> TEhben
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
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Tehben,
My 192V pack of Deka 9A31DT's (100aH at 20 hour rate) if I assume had 70aH at
my rates it would be 192V*70Ah=13.4KWh At 1100 lbs
thats 12.2 Wh/lb and at 360Wh/Mile *could* get me ~37 miles reliably.
My 120V pack of Crown CR-225's (225aH at 20 hour rate) if I assume have 160Ah
at my rates it would be 120V*160Ah=19.2KWh At 1380
lbs thats 13.9 Wh/lb and at the same 360Wh/Mile *could* get me 53 miles
reliably.
Mike,
Anchorage, Ak.
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Behalf Of Tehben Dean
> Sent: Monday, June 25, 2007 10:20 PM
> To: evlist
> Subject: ???kWh EV battery pack
>
>
> I know higher voltage less capacity and vise versa, but wondered are
> there some general kWh sizes that are used for different types of EVs
> e.g. pickups etc.?
> Or is it get as much as you can fit in without grossly over weighting
> the vehicle? :)
> (this is assuming Lead batt's)
>
> TEhben
>
>
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> I alot of people have claimed that it must be that expensive but I don't
> believe they have offered specific reasons why
>
> to sum up:
> the electronics parts cost
> circuit board
> any bussbar
> casing, cooling plumbing and prettyfication
> assembly/programming
>
> is either of those super expensive in your opinion and if so which and
> how much?
> I don't consider the design a cost since that's a one off so don't
> mention that
>
> do you have any costs to add?
>
> Dan
>
Kind of reminds me of an old story:
A well-dressed matron walks into a turn-of-the-century shop and asks the man
behind the counter where she can find the most unusual hat for that night's
ball.
"Take this as a gift" he says as he pulls off a long section of wide ribbon.
"What good is that?" she says, offended by the offering.
With a flourish, the man twists, twirls, and loops the ribbon into an ornate
hat, fixing it with a straight pin, and in short order, holds it up for the
woman to see.
"Oh, that will be perfect!" she exclaims.
He smiles, bows his head in appreciation, and says "That will be twenty dollars,
madam." [a lot of money back then]
The matron looks aghast and replies "That's outrageous! You were giving away the
ribbon!"
The man pulls out the straight pin, and with a flick, returns the hat to its
original shape, handing her an ordinary strip of red cloth. "The ribbon", he
replies, "was free"
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