EV Digest 6846
Topics covered in this issue include:
1) RE: 95 BMW 525i conversion
by Tom Parker <[EMAIL PROTECTED]>
2) Re: Why is there a delay of 1 hour on my messages??
by Tom Parker <[EMAIL PROTECTED]>
3) RE: 95 BMW 525i conversion
by Chip Gribben <[EMAIL PROTECTED]>
4) RE: 95 BMW 525i conversion
by "Guy Stockwell" <[EMAIL PROTECTED]>
5) Re: Quickest ET ever on lead acid
by Bill Dube <[EMAIL PROTECTED]>
6) RE: Energy loss in an EV and range now- rolling resistance
by "Phil Marino" <[EMAIL PROTECTED]>
7) Re: Why is there a delay of 1 hour on my messages??
by "R Patterson" <[EMAIL PROTECTED]>
8) Re: Energy loss in an EV and range
by "Peter VanDerWal" <[EMAIL PROTECTED]>
9) Re: ISE and Altair Nano - now grid stabilization
by =?ISO-8859-1?Q?Jukka_J=E4rvinen?= <[EMAIL PROTECTED]>
10) Re: Energy loss in an EV and range
by "Peter VanDerWal" <[EMAIL PROTECTED]>
11) Re: Power of DC - Intro
by Chip Gribben <[EMAIL PROTECTED]>
12) Re: Energy loss in an EV and range
by "Peter VanDerWal" <[EMAIL PROTECTED]>
13) Re: 95 BMW 525i conversion
by "Dmitri" <[EMAIL PROTECTED]>
14) RE: How increased mass affects performance (was: RE: Power of DC
- Sunday's Pool Party (the drag race))
by Jeff Shanab <[EMAIL PROTECTED]>
15) Re: Energy loss in an EV and range
by "Phil Marino" <[EMAIL PROTECTED]>
16) Re: Anybody tried battery switching from parallel strings to series
strings?
by "Marty Hewes" <[EMAIL PROTECTED]>
17) Re: Power of DC - Intro
by [EMAIL PROTECTED]
18) Re: Another BMW conversion (1994 318ti)
by Jeff Major <[EMAIL PROTECTED]>
19) Re: Thundersky
by "George Swartz" <[EMAIL PROTECTED]>
20) EV Dakota and Chargers on eBay
by Jeff Major <[EMAIL PROTECTED]>
21) Re: Thundersky
by Ian Hooper <[EMAIL PROTECTED]>
22) RE: How increased mass affects performance (was: RE: Power of DC -
Sunday's Pool Party (the drag race))
by "Guy Stockwell" <[EMAIL PROTECTED]>
23) RE: 95 BMW 525i conversion
by "Roger Stockton" <[EMAIL PROTECTED]>
--- Begin Message ---
On Mon, 2007-06-04 at 14:21 -0600, Dale Ulan wrote:
> So are you saying that with a 300v AC system you still won't get the
> performance of a 144v DC system?
It depends on which 300v AC system and which 144v DC system. You need
twice the current at 144v to get the same power as at 300v. The
batteries will sag, so you actually need more than twice the current.
I find it much better to think of torque than power. It's torque that
presses you into your seat, it's torque that accelerates you onto the
motorway. Electric motors provide constant torque from 0 rpm through to
the point where the controller comes out of current limit. This point is
directly proportional the battery voltage.
See this excel spreadsheet (it didn't work in openoffice last time I
tried) http://www.metricmind.com/data/performance.zip and adjust the
battery voltage to see how the curves change. I'm unaware of a DC motor
calculator similar to the above spreadsheet.
I would strongly encourage anyone worried about the performance of a
conversion to work out the wheel torque curve of the electric motor and
compare this to the ICE version of the car. The torque depends on the
gearing, motor, controller, battery voltage and current limits. You have
to compare the wheel torque because your gearing will be different on
the electric (I will only ever use second gear in the electric version
of my car).
For example:
I have an ICE version of the car I intend to convert. It's been on a
dyno, so I know the torque at 1000 rpm intervals. I converted that to
wheel torque in each gear. Then I looked at the motors available and
their torque curves at various voltages.
The motor, a 240v battery pack and a fixed reduction gearbox of about
7:1 gives me constant torque from 0km/h to about 55km/h. The wheel
torque (also constant between those speeds) is the same as the ICE
version in second gear at about 4000 rpm. In my car that is enough to
spin the wheels in the wet and accellerate very quickly.
>From 55km/h to the top speed of 120km/h (only 1 gear and the motor is
limited to 10,000 rpm) the torque drops in a non-linear fashion to about
the same wheel torque as the ICE version in 4th gear. So I expect the
experiance between 55km/h and 120km/h would be similar to driving the
ICE version with a CVT (if it had a CVT).
I don't know what the peak power of the system will be, and I don't
care. I only care about what will make the car accellerate, the torque.
The above numbers are from memory and somewhat approximate. I did these
calculations a few months ago. Also, the electric version will be about
15% heavier, I haven't corrected for this.
> Wrightspeed X1, Tesla, and AC Propulsion's TZero are all AC and
> they perform pretty well. Expensive, but fast.
These are all very lightweight vehicles. Perhaps all under 1000kg.
> I recall seeing
> an impressive burnout with Victor's ACRX....
Not to put down the ACRX (I know nothing of it's configuration during this
demonstration), but a burnout can be done with very little power if you
have the right tyres and road surface.
--- End Message ---
--- Begin Message ---
On Tue, 2007-06-05 at 09:02 -0700, GWMobile wrote:
> And this is why I hate auto spam filters. At some point they make lists
> serves useless. I find spam is one of the most over discussed over
> complained about things ever.
> It takes two seconds to skip to the next message.
I get about 200 spam messages a day if I turn off my spam filter. That's
not something you can just say "oh well" and delete one by one.
I think you either already have a good spam filter (at your isp) or you
don't get much spam sent to your address. Either way, be greatful.
> What is REALLY a problem is having to resned that takes a long time and
> really IS a pain.
> messages delayed or falsely screened as spam.
I'm not sure if a spam filter on the mailing list is actually necessary.
Non-members can't post. How many spammers sign up? I'm not a mailing
list spam expert, so maybe they do sign up?
--- End Message ---
--- Begin Message ---
Roger Stockton wrote:
I don't know that a 144V flooded pack is even an option anyway: can it
physically fit? Remember, floodies have to be installed
vertically, and
must be accessible from above for watering and cleaning, etc. Even
cramming the engine bay and trunk full may not be enough without
tossing
the rear seat and stuffing more where it used to be.
18 8-volt US Battery floodeds will work for 144 volts. This is the
setup I currently have in Wattson, my Ford Escort.
There are 4 above the motor. 3, side by side, in front of the motor
where the radiator was and 11 in the back.
I have the HCs. I think they are 69 pounds each and 178 AHrs
Chip
--- End Message ---
--- Begin Message ---
Where is Cliff located?
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Victor Tikhonov
Sent: Wednesday, June 06, 2007 4:23 AM
To: ev@listproc.sjsu.edu
Subject: Re: 95 BMW 525i conversion
Guy,
Your range is mainly a function of the amount of Wh stored
on board (weight of the lead in your case). Double the weight =
double Wh and almost double the range (almost - because
heavier vehicle will spend more Wh per mile, but nowhere
near twice as much).
As far as performance, I'll stay away from this debate because
of course my opinion is biased. Go with DC for low voltage pack.
If you'll have chance, visit Cliff Rassweiler in Florida,
have a ride in his Electric Imp and then call me.
If you'll ever get an AC system matching with your car/battery well,
you will never go back to DC, but it's mainly a matter of cost.
There is no doubt AC systems are superior for application than
DC ones, it's just may not worth it or be affordable for
many individuals.
Simple proof: if identical raw power DC and AC systems would
cost the same, everyone in their right mind would choose AC.
So it's only money talk really.
--
Victor
'91 ACRX - something different
[EMAIL PROTECTED] wrote:
> No worries, I'm looking for solid advice and if my
> 60mi range is not realistic for this vehicle, I'll
> just have to get something else! I bought this car
> for a very good price and can drive it while I
> convert another! Sounds like I need to focus on
> 2500lbs or less for curb weight! I really appreciate
> all of the input!
>
> Guy
>
>
> ------- Original Message -------
>>From : Paul[mailto:[EMAIL PROTECTED]
> Sent : 6/5/2007 7:40:36 PM
> To : ev@listproc.sjsu.edu
> Cc :
> Subject : RE: Re: 95 BMW 525i conversion
>
> On Jun 5, 2007, at 7:34 AM, John Wayland wrote:
>
>> As a stand-alone, Roger's point on this is
> partially true. The
>> problem with Roger's take on this though, is that
> he has
>> 'conveniently' overlooked the context of this entire
>> discussion...Guy's BMW conversion. In this heavy
> car, to get the
>> same DC torque at the wheels with the proposed AC
> system, he's
>> going to have to somehow, find a BMW rear gear set
> in the 7:00
>> ratio range. Roger, do you have a handle on the
> whereabouts of
>> these mythical super-low differential gears that
> will fit his BMW's
>> rear end? If Guy could find a set (doubtful) they'd
> surely be $2000
>> just for the ring and pinion...more cost, just to
> justify AC. Keep
>> in mind, that while Guy is shopping around for
> these costly gears,
>> he'll still have to now change his simple, easy,
> and low cost
>> flooded cell pack to a more expensive AGM pack with
> 25-30 BMS regs
>> for each battery, too.....again, AC makes the cost
> of Guy's
>> conversion go through the roof.
>
> Yea, but do you expect that 1st gear will be used
> with a the proposed
> 144 volt system and an ADC 9 inch motor? The
> suggested zilla setup
> (1000 amp motor limit, 500 amp battery limit to keep
> GC batteries
> alive) would provide maximum torque up to around 63
> motor volts. What
> rpm is a 9 inch turning at 63 volts and 1000 amps? I
> suspect its to
> low to make 1st gear useful. With the higher revving
> AC system a most
> of the needed extra multiplication could be provided
> by using 1st.
>
> I'm going to take a WAG at the rpm range the proposed
> system would
> get full torque out of the 9 inch motor based on the
> following:
>
> 1. You know the ADC 9 inch, I've never used one - you
> say about 300
> ft/lb. of torque (previous post in this thread) so I
> will use that as
> the torque at 1000 amps.
>
> 2. At 1000 amps and 63 (motor) volts the motor is
> about 80% efficient
> - I suspect I'm being generous.
>
> 3. The GC batteries will sag to 1.75 vpc at 500 amps
> (that is my
> experience.)
>
> 4. Power in will equal power out minus efficiency losses.
>
> Conclusion: I get 300 ft/lb. of torque (1000 motor
> amps) up to about
> 1200 rpm.
>
> This is a bit of my experience for Guy. GC (golf
> cart) batteries do
> not add up to "good" performance in any vehicle. Even
> with 1/2 the
> weight of the converted car in GC batteries you will
> have less than 1
> horsepower available per 40 lb. of vehicle weight (a
> Geo Metro is
> better.) With 1/3 of the converted vehicle weight in
> GC batteries
> performance will be in the range of an old 36 HP
> Beetle. (I've owned
> 2 of them, they are fine but in no way
> "performance".) Sorry for
> being a downer on this point; I don't want to create
> false expectations.
>
> Paul "neon" G.
>
>
>
--- End Message ---
--- Begin Message ---
Dennis ran 10.23 in Denver on AGMs.
He also ran 8.801 on lead-acid TMF, once, in Sacramento. All his
other TMF runs were 8.9 and above, as I recall, but I could easily be mistaken.
The best we ever did on AGMs was low elevens, as I recall. We did
9.45 @152mph on TMF lead-acid, however.
Bill Dube'
At 06:24 PM 6/5/2007, you wrote:
In a message dated 6/5/2007 5:01:48 PM US Mountain Standard Time,
[EMAIL PROTECTED] writes:
> Quickest ET ever on lead acid
> Date:6/5/2007 5:01:48 PM US Mountain Standard Time
> From:[EMAIL PROTECTED]
> Reply-to:ev@listproc.sjsu.edu
> To:ev@listproc.sjsu.edu
> Received from Internet:
>
>
>
> This probably goes out to Dennis and Bill but i'm trying to find out
> what is the quickest 1/4 mile ET ever run on plain old lead acid
> batteries? Not TMF or Inspira but plain old off the shelf bats anyone
> could buy. Sort of like the quickest ever on gasoline, alchohol, etc...
> I know I saw both Bill and Dennis run high tens/low elevens in Vegas.
> OJ ran a 10.80. Can anyone help me out here?
>
> Shawn Lawless
> ______________
You can ck.the nedra records but I believe I ran 10.21 at 121mph in Denver at
one of Bills races.That was at 240 volts 2 strings 13ah hawkers.
Dennis
--- End Message ---
--- Begin Message ---
From: Dan Frederiksen <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Energy loss in an EV and range
Date: Wed, 06 Jun 2007 07:50:28 +0200
this might have been covered many times before here but I was talking
energy loss with my (filthy gas car owning :) friend the other day and we
arrived at the conclusion that loss through rolling resistance (and thus
car wieght) was insignificant at highway speeds compared to the wind
resistance. as little as 1 percent.
Can you tell me what data (and/or calculations? led you to this value of 1 %
?
The US Department of Energy ( as quoted in Transportation Research Board
Specail Report 286 : "Tires and Passenger Vehicle Economy" ) presents this
data for "late model mid-sized passenger cars" :
The percentage of energy loss due to rolling resistance is 31 % for urban
driving and 35% for highway driving. Quite a bit higher than 1%.
For a typical ev ( with higher weight than the typical ICE) the rolling
resistance numbers would likely be a bit higher than this.
Phil Marino
Assuming this is not entirely wrong, wouldn't this mean that a very heavy
yet small wind profile car could go just as long on a given battery amount.
and that further this high weight could be used for many more batteries...
in other words that some elongated vehicle with a normal car windprofile
could be loaded up with a lot of lead acid and thus achieve well past 100
mile range?
not only that but benefit further from the lower internal loss of the
battery because the discharge rate is less per battery
that perhaps some sleek estate car could be made to break the 200mile
barrier on lead acid : )
volvo, bmw, audi might have some estates with a nice wind profile
or even just a regular long but narrow sedan since you probably wont need
to stack them so high that you need the estate boot anyway.
it would have to be a 2 seater only then but wouldn't it be an interesting
challenge? : )
it presumably wouldn't be a great dragster but we don't really need drag
racing as much as range.
lead acids are so relatively cheap that it should be doable. and there are
batteries outthere that claim over 50Wh/kg but don't really know if they
are lying or not
Dan
_________________________________________________________________
Need a break? Find your escape route with Live Search Maps.
http://maps.live.com/default.aspx?ss=Restaurants~Hotels~Amusement%20Park&cp=33.832922~-117.915659&style=r&lvl=13&tilt=-90&dir=0&alt=-1000&scene=1118863&encType=1&FORM=MGAC01
--- End Message ---
--- Begin Message ---
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* ---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 ---
This would be (mostly) true, if you alway ran at a constant speed on a
perfectly flat road.
However, in real life, you have hills (even small ones) and acceleration
to consider. The energy needed to climb even a shallow grade (1%) makes
aerodynamic drag insignificant even in normal weight EVs.
Plus, making a car longer also increases it's drag, though not at the same
rate as making it wider.
> this might have been covered many times before here but I was talking
> energy loss with my (filthy gas car owning :) friend the other day and
> we arrived at the conclusion that loss through rolling resistance (and
> thus car wieght) was insignificant at highway speeds compared to the
> wind resistance. as little as 1 percent.
> Assuming this is not entirely wrong, wouldn't this mean that a very
> heavy yet small wind profile car could go just as long on a given
> battery amount. and that further this high weight could be used for many
> more batteries...
>
> in other words that some elongated vehicle with a normal car windprofile
> could be loaded up with a lot of lead acid and thus achieve well past
> 100 mile range?
> not only that but benefit further from the lower internal loss of the
> battery because the discharge rate is less per battery
>
> that perhaps some sleek estate car could be made to break the 200mile
> barrier on lead acid : )
>
> volvo, bmw, audi might have some estates with a nice wind profile
> or even just a regular long but narrow sedan since you probably wont
> need to stack them so high that you need the estate boot anyway.
>
> it would have to be a 2 seater only then but wouldn't it be an
> interesting challenge? : )
> it presumably wouldn't be a great dragster but we don't really need drag
> racing as much as range.
>
> lead acids are so relatively cheap that it should be doable. and there
> are batteries outthere that claim over 50Wh/kg but don't really know if
> they are lying or not
>
> Dan
>
>
--
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
legalistic signature is void.
--- End Message ---
--- Begin Message ---
Usually the weight is not an issue. Flow batteries tend to weight and
also flywheels.
Some of the stabilization units need to be portable, durable and noise
free. Also instant operation is required.
Some MWh programs with Lithium are on the way. After they finish.. we
know more. Calculations do look good.
-Jukka
Zeke Yewdall kirjoitti:
There's also a company in MA (I think) that is doing flow batteries
for large stationery energy storage for load leveling. 10MWH and up
sizes I think. I'll try to find out their name.
Zeke
On 6/5/07, Kaido Kert <[EMAIL PROTECTED]> wrote:
On 6/5/07, john fisher <[EMAIL PROTECTED]> wrote:
> Thats an interesting idea. Batteries look expensive until you price
a gas turbine.
> Another market might be co-generation-stabilization and emergency
power. Permitting diesel gensets is getting harder
> with the air pollution agencies, and they are notoriously unreliable
due mostly to improper maintenance and testing.
> Is anyone working on this Jukka?
>
> JF
They are doing this with flywheels, which is a much better stationary
storage unit than batteries ( almost no maintenance, no cycle life
issues, good energy & power density )
See http://www.greencarcongress.com/2006/09/california_ener.html for
example
similar units ( 25kwh ) can be used as fast charge stations for EVs
-kert
--- End Message ---
--- Begin Message ---
> give me a rough estimate of the percentage for a sedan at 65mph
>
Uve's online EV calculator indicates that for the typical conversion
moving at 60 mph, approx 25% of the energy is used to overcome rolling
resistance.
Note: this is on flat ground and assumes an average Cd.
With a more streamlined vehicle, carrying more mass (which would INCREASE
rolling resistance), this would probably increase to 50% or more.
--
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
legalistic signature is void.
--- End Message ---
--- Begin Message ---
Hey Jim!!
Jim Husted wrote:
Hey all
First off sorry to hear about the rain, kind of a
bummer. At least it only affected those stupid
annoying 1/4 mile guys 8^o
Yea, the anti-EV Vortex has reared it's ugly ahead again. But
fortunately the whole weekend wasn't a washout. The AutoCross and
ScooterCross was fun. And Shawn is planning to run his stuff tonight
in Ohio.
Joe Lado gave me a write. Kinda cute asking if it'll
power some hummer sized project LMAO! Being a
hi-Torque 6.7 doesn't make it a Warp 11 now, hehe.
Guess maybe he was thinking he'd just roar in, roll
over "your car" and there'd be no competition next
year hehehe. Kind of a take that Mr. Chip 8^o
HeHe, Joe didn't mention he wanted 3 more of those motors? One for
each wheel :-) But hey an Electric Monster Truck competition sounds
fun. I think several people wanted my car squashed this past weekend.
Anyway it sounds a bit like the Joliet trip in that
you just got more time to play in the puddles like
when we were kids. Although back then the security
guard would chase us off the premises not stop and
watch for the WZ vs Joule Injected run at the Wallmart
8^o
Maybe we should bag EVs with wheels and bring along electric powered
jet skis.
EVen though it got rained out, I have such fond
memories of Joliet, I really do, Hopefully you all
went home with those same feelings. It's got to be a
bummer to not have EVerything go as planned being you
worked so darn hard to plan it though huh?!
If only the rain could have held off for an hour then everyone would
have been able to make a run or two.
It's actually Todd Dore's fault. I knew we were in trouble when he
came down for the event. He must have brought the anti-EV vortex with
him from Joliet. I think those Fox Valley shirts they wear must
attract the rain gods :-)
But actually sloshing around in the rain in a tropical storm isn't
that bad. The water is pretty warm. It's just all that high voltage
wiring laying around the pits like giant electric eels that gets me a
little nervous.
Yea, Joliet was a blast at the Pep Boys parking lot.
If nothing else you get a little rest now before you
have to start running around like a chicken on a
Rudman load bank again 8^o Okay breaks over, you got
those Wayland invite shirts done yet 8^P
Shhh, don't mention the shirts yet :-)
Cya
Jim Husted
Hi-Torque Electric
Chip
--- End Message ---
--- Begin Message ---
> However, in real life, you have hills (even small ones) and acceleration
> to consider. The energy needed to climb even a shallow grade (1%) makes
> aerodynamic drag insignificant even in normal weight EVs.
Correction, I shouldn't have said "insignificant, but the energy need for
drag is less than for the hill.
--
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
legalistic signature is void.
--- End Message ---
--- Begin Message ---
Miami. Look at his webpage www.proev.com
----- Original Message -----
From: "Guy Stockwell" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, June 06, 2007 8:12 AM
Subject: RE: 95 BMW 525i conversion
Where is Cliff located?
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Victor Tikhonov
Sent: Wednesday, June 06, 2007 4:23 AM
To: ev@listproc.sjsu.edu
Subject: Re: 95 BMW 525i conversion
--- End Message ---
--- Begin Message ---
It would be nice if we had a chart of the club vehicle's wh/mile ordered
by curbweight including driver.
Here is mine.
1987 300zx 4050LB 450wh/mile 288V AGM Z1k 9" + gearbox
It seams excessive, but I am not sure after reading about the BMW
--- End Message ---
--- Begin Message ---
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: Energy loss in an EV and range
Date: Wed, 6 Jun 2007 07:12:19 -0700 (MST)
This would be (mostly) true, if you alway ran at a constant speed on a
perfectly flat road.
However, in real life, you have hills (even small ones) and acceleration
to consider. The energy needed to climb even a shallow grade (1%) makes
aerodynamic drag insignificant even in normal weight EVs.
Peter
For my car at least, the aero drag at 60 MPH is about twice the "hill drag"
for a 1% slope.
For an Echo ( at 2800 lbs ev weight) the air drag ( based on published Cd of
0.29) is 54 lbs. The slope drag is 1% of the weight, or, 28 lbs. So, the
air drag is almost double the hill drag for this example.
For this car, the aero drag equals the 1% hill drag at about 43 MPH.
Phil Marino
_________________________________________________________________
Need a break? Find your escape route with Live Search Maps.
http://maps.live.com/default.aspx?ss=Restaurants~Hotels~Amusement%20Park&cp=33.832922~-117.915659&style=r&lvl=13&tilt=-90&dir=0&alt=-1000&scene=1118863&encType=1&FORM=MGAC01
--- End Message ---
--- Begin Message ---
Thank you for the explanation Dale. What I'm wondering is if the controller
is limiting peak current during on time to protect itself, resulting in a
net loss of wattage delivered to the motor, before it limits RMS current to
protect the motor? At anything less than 100% duty cycle, that peak current
could get pretty high trying to provide the same power. If the controller
limits based on peak current during the on time to protect itself, then
lowering battery voltage may result in more watts delivered to the motor by
keeping the peak current out of controller protection current limiting?
When you say the motor current limit is 1000 amps, is that 1000 amps RMS, to
avoid toasting the motor with heat, or 1000 amps peak, to avoid killing the
controller's switching devices? Let's say it's a Zilla 1K. Is the Zilla
limited to 1K peak during the on time to the motor, or 1K RMS to the motor,
or something greater than 1K peak? If there is a limit to the peak current
during on time, then there might be an advantage to keeping the battery
voltage down to avoid excessive peak currents. I'm thinking of my days in
audio amp design, where there were two things to avoid, peak currents and
heating effects in the output devices.
What I'm wondering is, if I'm drag racing, looking for maximum wattage
delivered to the motor, would I be better off with lower battery volts until
RPM comes up to avoid controller peak current limiting? I'm concerned that
if battery voltage is too high, then the current draw during on time will be
cut back by the controller, limiting wattage applied to the motor. Would I
be better off with lower voltage and wider pulse width to avoid the
controller limiting the on time current to protect itself? Or is a Zilla
smart enough to increase frequency so that the current during on time is
limited by motor inductance and never ramps up enough to toast the
controller, in which case trying to match voltage applied to voltage
required would be a grand waste of time?
Thanks,
Marty
----- Original Message -----
From: "Dale Ulan" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, June 06, 2007 12:25 AM
Subject: RE: Anybody tried battery switching from parallel strings to series
strings?
....
Normally a controller operates in 'continuous conduction mode' which is
to say that the motor current ramps UP during the switch-on time, and
ramps DOWN during the switch-off time. The PWM frequency is chosen to
maintain the ripple current at a reasonable amount. So the pulse widths
being relatively short should be fine. A freewheeling diode maintains
the current through the motor with the MOSFET off.
For motor vs. battery current limiting, you normally would set the
motor current to some maximum (say, 1000 amps so you don't fireball
the thing), and then limit battery current to some value so you
don't cook that end of things. The current setpoint will be set to
the lower of:
a. Motor maximum current
b. Battery maximum current / duty cycle
So if the controller is running a 30% duty cycle and your battery current
limit is 500A, the maximum allowed motor current from the battery current
limitation function will be 500A / 0.300 = 1666 amps. If the motor current
limit is 1000 amps, then the controller will current limit at 1000 amps.
As the speed builds up, the duty cycle will ramp up to maintain the
current
at 1000 amps. Once the duty cycle exceeds 50%, the motor current will then
drop off. At a 60% duty cycle, the desired motor current will be 500A /
0.600
= 833 amps. Since this value is lower than the motor current limit of
1000A,
the controller will current limit at 833 amps. You can measure battery and
motor voltage and achieve the same result - depends how the controller
designer
wanted to do it.
Note that the peaks of the current waveform (from the battery) are at 833
amps
but since the current draw is combined with times where there is no
current
flowing, then the averaged current will be 500 amps.
At the high end, when the duty cycle is equal to 100%, the motor takes
only
what it can from the battery - the controller is not current limiting
any more. At this point, motor back-emf controls current.
The same trick is used in quite a few of the current-controlling circuits
that I get to design.
-Dale
--- End Message ---
--- Begin Message ---
speaking of big vehicles...
Lets electrify one of these....
http://www.coldwarremarketing.com/images/475XXXX.jpg
Tho, I think that UQM has given some hugeish construction-like vehicles
hub-motors...
A picture of a vehicle with their motors...
http://www.gizmag.com/go/5576/
"Crusher's hybrid electric system is silent, using a high-performance
SAFT-built lithium ion battery module which delivers power to the six,
in-wheel UQM traction motors located in the hub drive system of each
wheel. "
So when do you think we'll be uttering uqm-type motors in the same breath
as other EV motors?
Are these things coming down in price yet?
Any AC controllers out there coming down in price?
Almost 10k to convert an old 1986 pickup with worn-out upholstery (which I
will eventually replace) is somewhat high.
I've enjoyed building/converting this truck (which still isn't on the
road, looking for vacuume pumps for the brakes, among other things) -
but not everyone has the skill, time, wherewithal, or desire to not fund
terrorists by converting their own vehicle...
Not to mention the "2-gallons of gas range" is still a severe downside,
the availability of $20,000 lithium ion batteries notwithstanding (again,
price).
Yes, I'm impatient.
Bill, Lee, Jim, Chip - everyone else, keep up the outstanding work!
Hurry up and develop the Mr Fusion... Then we won't have any more issues
with battery weight (lead sled), 6,700 laptop batteries+cooling system
(tesla), etc.
Chip Gribben <[EMAIL PROTECTED]>
Sent by: [EMAIL PROTECTED]
06/06/2007 08:52
Please respond to
ev@listproc.sjsu.edu
To
ev@listproc.sjsu.edu
cc
Subject
Re: Power of DC - Intro
Hey Jim!!
Jim Husted wrote:
> Hey all
>
> First off sorry to hear about the rain, kind of a
> bummer. At least it only affected those stupid
> annoying 1/4 mile guys 8^o
Yea, the anti-EV Vortex has reared it's ugly ahead again. But
fortunately the whole weekend wasn't a washout. The AutoCross and
ScooterCross was fun. And Shawn is planning to run his stuff tonight
in Ohio.
> Joe Lado gave me a write. Kinda cute asking if it'll
> power some hummer sized project LMAO! Being a
> hi-Torque 6.7 doesn't make it a Warp 11 now, hehe.
> Guess maybe he was thinking he'd just roar in, roll
> over "your car" and there'd be no competition next
> year hehehe. Kind of a take that Mr. Chip 8^o
HeHe, Joe didn't mention he wanted 3 more of those motors? One for
each wheel :-) But hey an Electric Monster Truck competition sounds
fun. I think several people wanted my car squashed this past weekend.
> Anyway it sounds a bit like the Joliet trip in that
> you just got more time to play in the puddles like
> when we were kids. Although back then the security
> guard would chase us off the premises not stop and
> watch for the WZ vs Joule Injected run at the Wallmart
> 8^o
Maybe we should bag EVs with wheels and bring along electric powered
jet skis.
> EVen though it got rained out, I have such fond
> memories of Joliet, I really do, Hopefully you all
> went home with those same feelings. It's got to be a
> bummer to not have EVerything go as planned being you
> worked so darn hard to plan it though huh?!
If only the rain could have held off for an hour then everyone would
have been able to make a run or two.
It's actually Todd Dore's fault. I knew we were in trouble when he
came down for the event. He must have brought the anti-EV vortex with
him from Joliet. I think those Fox Valley shirts they wear must
attract the rain gods :-)
But actually sloshing around in the rain in a tropical storm isn't
that bad. The water is pretty warm. It's just all that high voltage
wiring laying around the pits like giant electric eels that gets me a
little nervous.
Yea, Joliet was a blast at the Pep Boys parking lot.
> If nothing else you get a little rest now before you
> have to start running around like a chicken on a
> Rudman load bank again 8^o Okay breaks over, you got
> those Wayland invite shirts done yet 8^P
Shhh, don't mention the shirts yet :-)
>
> Cya
> Jim Husted
> Hi-Torque Electric
Chip
--- End Message ---
--- Begin Message ---
--- Ian Jordan <[EMAIL PROTECTED]> wrote:
> I'm thinking of converting a 1994 BMW 318ti
> hatchback to an EV, but
<snip>
> Can you run an advanced timing motor like the Warps
> in reverse in
> order to get reverse out of a direct drive system? I
> know you can't
> run them full time without messing with the timing,
> but is it OK for
> very low duty cycle stuff like reverse?
>
Ian,
I think you'd probably be O.K. for reverse---low speed
(therefore low motor voltage), short duration and
occasional use. Looks like White Zombie does it this
way.
http://www.plasmaboyracing.com/whitezombie.php
Jeff
____________________________________________________________________________________
Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news,
photos & more.
http://mobile.yahoo.com/go?refer=1GNXIC
--- End Message ---
--- Begin Message ---
Rich, I emailed Thundersky. Has anyone ever received a response from
them? Are their Lithium batteries actually availble to us? I suspect that
the little guys like me, trying to do a conversion, will be out of luck, as
all available lithium battery production will be scarfed up by GM or other
big players for some time to come.
On Tue, 5 Jun 2007 16:31:27 -0700, Rich Rudman wrote
> Wasn't that 2000 cycles to %80 DOD
> and 3000 cycles to %70 dod.
>
> Rich Rudman
> [EMAIL PROTECTED]
> Manzanita Micro
> 360-297-7383,
> Cell 360-620-6266
> Production shop 360-297-1660
> FAX at Metal shop 1-360-297-3311
>
> ----- Original Message -----
> From: "Rush" <[EMAIL PROTECTED]>
> To: <ev@listproc.sjsu.edu>
> Sent: Friday, June 01, 2007 6:41 PM
> Subject: Re: Thundersky
>
> > John wrote -
> >
> > > So, that's about $86/cell?
> > >
> >
> > That's what I get also.
> >
> > At the website it says 3C rate, and good for 1000 cycles to 80% DOD.
> >
> > And you have to add on a BMS for the pack.
> >
> > Still expensive compared to lead acids.
> >
> > Rush
> > Tucson AZ
> > www.ironandwood.org
> > www.TEVA2.com
> > www.Airphibian.com
> >
--- End Message ---
--- Begin Message ---
If anyone is interested, search electric vehicle on
eBay. Several big boy Enerpro chargers and Magne
chargers. Also this Dodge Dakota. 160124329720
I rode in this truck back in '94 or '95. Had a nice
Prestolite 9" series wound traction motor (MNF type I
think). At that time it was mounted under the hood
coupled to a pulley/belt CVT, from a snowmobile, I
think. Well, the designers and converters did a
really nice job of installation of the electric
equipment, but neglected to comprehend how that CVT
would interact with the series motor. The result was
a top speed of about 25 mph.
The utility company drove it around a little and
showed it off at company picnics, but never did much
else. Very few miles. I have no idea what the range
was. You get too tired going at 25 to care. Years
later I talked with a couple a power plant mechanics
who had the truck. They threw out the snowmobile
pulley crap and installed the motor near the rear axel
with a fixed ratio gear box or belt or chain. I never
saw that up close or know any more about it.
I think the seller on eBay tells the story as best he
can. There is a top speed of 90 mph and range of 80+
listed. I think this is totally a dream. Maybe the
original intent, but I suspect never realized.
Having said all this, I live near this guy. Well 50
miles. So if anyone is interested in bidding, I could
assist to some degree.
Later,
Jeff
____________________________________________________________________________________
Finding fabulous fares is fun.
Let Yahoo! FareChase search your favorite travel sites to find flight and hotel
bargains.
http://farechase.yahoo.com/promo-generic-14795097
--- End Message ---
--- Begin Message ---
I know of many people here in Australia who have purchased batteries
from ThunderSky without any problems, and they will definitely sell
to individuals. Though perhaps there are different regulations for
bringing lithium cells into the US vs Australia.
At any rate you might want to email TS's international sales rep
directly at [EMAIL PROTECTED] - he should be able to help.
-Ian
On 06/06/2007, at 11:25 PM, George Swartz wrote:
Rich, I emailed Thundersky. Has anyone ever received a response from
them? Are their Lithium batteries actually availble to us? I
suspect that
the little guys like me, trying to do a conversion, will be out of
luck, as
all available lithium battery production will be scarfed up by GM
or other
big players for some time to come.
On Tue, 5 Jun 2007 16:31:27 -0700, Rich Rudman wrote
Wasn't that 2000 cycles to %80 DOD
and 3000 cycles to %70 dod.
Rich Rudman
[EMAIL PROTECTED]
Manzanita Micro
360-297-7383,
Cell 360-620-6266
Production shop 360-297-1660
FAX at Metal shop 1-360-297-3311
----- Original Message -----
From: "Rush" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, June 01, 2007 6:41 PM
Subject: Re: Thundersky
John wrote -
So, that's about $86/cell?
That's what I get also.
At the website it says 3C rate, and good for 1000 cycles to 80% DOD.
And you have to add on a BMS for the pack.
Still expensive compared to lead acids.
Rush
Tucson AZ
www.ironandwood.org
www.TEVA2.com
www.Airphibian.com
--- End Message ---
--- Begin Message ---
How about adding range and performance info as well? Speaking of, how is the
range on your 300zx?
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Jeff Shanab
Sent: Wednesday, June 06, 2007 9:24 AM
To: Electric Vehicle Discussion List
Subject: RE: How increased mass affects performance (was: RE: Power of DC -
Sunday's Pool Party (the drag race))
It would be nice if we had a chart of the club vehicle's wh/mile ordered
by curbweight including driver.
Here is mine.
1987 300zx 4050LB 450wh/mile 288V AGM Z1k 9" + gearbox
It seams excessive, but I am not sure after reading about the BMW
--- End Message ---
--- Begin Message ---
Chip Gribben wrote:
> 18 8-volt US Battery floodeds will work for 144 volts. This is the
> setup I currently have in Wattson, my Ford Escort.
>
> There are 4 above the motor. 3, side by side, in front of the motor
> where the radiator was and 11 in the back.
>
> I have the HCs. I think they are 69 pounds each and 178 AHrs
I've only seen your car with Optima's onboard (Woodburn, some years
back, unless I'm confusing yours with someone else's); I can't even
imagine it with 18 floodies stuffed in! (I notice you're not in the EV
Album either....).
144V of 8V floodies is not the same as 144V of 6V floodies from power,
range, or longevity perspectives.
144V of 6V is 33% more volume and weight to squeeze in...
A local EVer has 120V of 6V floodies in his Escort/Lynx, not sure how
many are stuffed in the engine bay, but squeezing the remainder into the
back resulted in a box occupying the entire space previously used for
the rear seat and hatch/trunk cargo space.
Cheers,
Roger.
--- End Message ---
