EV Digest 2582
Topics covered in this issue include:
1) Re: Questions about wiring aux 12v bat to dc conv
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
2) Re: Current Eliminator News(3 more days)
by [EMAIL PROTECTED]
3) Re: thoughts and questions
by "Joseph H. Strubhar" <[EMAIL PROTECTED]>
4) Re: Current Eliminator News (Today a 62 mile race)
by [EMAIL PROTECTED]
5) Re: Nedra in Vegas 2003
by [EMAIL PROTECTED]
6) Re: Measuring Current
by [EMAIL PROTECTED]
7) Re: thoughts and questions
by "1sclunn" <[EMAIL PROTECTED]>
8) Re: Current Eliminator News(3 more days)
by "1sclunn" <[EMAIL PROTECTED]>
9) Re: DCP
by Rich Rudman <[EMAIL PROTECTED]>
10) Fw: thoughts and questions
by "1sclunn" <[EMAIL PROTECTED]>
11) Re: Kick in the pants 0 to 60 in 2.5 seconds.
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
12) Re: thoughts and questions
by Lee Hart <[EMAIL PROTECTED]>
13) Tom Swift and his Electric Runabout
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
14) Re: Air Cooled Controllers
by Lee Hart <[EMAIL PROTECTED]>
15) Re: liquid cooled 8" ADC
by Lee Hart <[EMAIL PROTECTED]>
16) February Meeting 2/11 Seattle EV Association
by "Steven S. Lough" <[EMAIL PROTECTED]>
17) RE: Air Cooled Controllers
by "George Tylinski" <[EMAIL PROTECTED]>
18) Re: Kick in the pants 0 to 60 in 2.5 seconds.
by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
19) Re: Air Cooled Controllers
by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
20) Re: Current Eliminator News(3 more days)
by Rod Hower <[EMAIL PROTECTED]>
21) Re: thoughts and questions
by Henry Deaton <[EMAIL PROTECTED]>
--- Begin Message ---
I found a battery that is sealed and will take a charge under 14.2 forever
14.2 to 14.9 is float. If your converter is around 13.9 or so it shouldn't
hurt the battery. Lawrence Rhodes.....
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Saturday, February 08, 2003 11:45 AM
Subject: Questions about wiring aux 12v bat to dc conv
> I'm trying to wire up a 12v aux battery to my dc converter, and plan to
> power the standard accessories off the 12v instead of directly from the dc
> converter. Rather than having the dc converter alway maintain the 12v aux
at
> 12.0+/1vdc, is there some way to rig up more of a charging circuit? In
other
> words, set it up as the following:
>
> aux bat dc converter
> 13v stop charging (or whatever the top setpoint v is)
> drop in v nothing
> 11.0v start charging (or whatever the bottom setupoint v is)
> rise in v charge
> 13v stop charging...
>
> Does this make sense? What is needed to switch the current output from the
> dc conv on and off to accomplish this?
>
> BR,
> Ed T
>
--- End Message ---
--- Begin Message ---
Another weekend at the races,the currenteliminator dragster ran 5 times on
friday nite at Firebird raceway.ETs were 10.48 10.46 10.431 10.411 an 10.40
.MPH#s 125 on all but one of the runs.These runs happened in a 90 minute time
frame.My charging time between runs using my 15kw3phase Miller welder genset
was13minutes.I had both my series charger and my design micro charger system
hooked to the car at the same time(micro charger capable of max31amps
min..01) I am trying to set the car up for bracket racing,so a fast
turnaround must be practiced.These easy on the battery pack an car runs were
with the batts.charged to about 80% capacity.
DAY TWO Speedworld Motorplex Six more runs with the ETs
11.57 to11.63 an still the MPHs at 125.A slow et with hi mph will really
throw the ICE bracket racers off.My goal 11,80 at 135mph.with a throttle stop
at 1100feet for 100feet before the car turns back on til the end of the qt.
mile.This will confuse the bumper racers.Charging times were limited to 13
minutes again.Otmars ZILLA controller ran perfectly with just air cooling(at
these easy ets motor amps are less than 1000amps)There are times I may have
to wait up to an hour in the stageing lanes without working on the car thus I
had to know if the car can be coninsent without ice water cooling.It Is....I
do have to work on geting the Ets closer together.
DAY three NEXT POST
Dennis KILL A WATT BERUBE Worlds Quickest EV currenteliminator.net
--- End Message ---
--- Begin Message ---
Hi, Garry - and welcome to the list!
You've got one little problem in your calculations, and that's called
overspeeding the motor. If you can find a transmission with a high enough
gear ratio, you will be alright - but most forklift motors aren't made to
have a high RPM, and your motor will spontaneously disassemble if you over
speed it.
Joseph H. Strubhar
E-Mail: [EMAIL PROTECTED]
Web: www.gremcoinc.com
----- Original Message -----
From: "garry" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Sunday, February 09, 2003 7:21 AM
Subject: thoughts and questions
> Hi Folks,
>
> I'm a learner in the ev field so please forgive me if I don't know what im
> talking about or simply seem misinformed.
>
> I have always wanted to build a car, but never really got to do more than
> customize an existing car.
>
> In my garage I have a Mclaren m6gt replica body shell that looks like its
> going to be my first ev car project.
>
> If you don't know what this is you will probably be familiar with the Ion
ev
> and this is the same as that, full fiberglass body on a space frame.
>
> I have an electric pushbike conversion and an electric motorbike
conversion
> I have done, so I have a basic grasp of how this all works and what breaks
> and what overheats.
>
> My power plant for this looks like its going to come from a Lansing bagnal
> toer which is basically a forklift without forks.
>
> Its 48 volts and the panel is rated at 205 amps and assuming the motor can
> handle this I calculate from this that I have a motor around 12 horsepower
> (allowing a margin for safety on the control panel).
>
> To determine if this was a good unit for a conversion I attached a 2000 kg
> load to it and dragged it up the road, it completed this effortlessly,
> indicating that if it can pull far more than its going to in a car, that
it
> will pull the car faster than the 12 kph it currently runs at.
>
> While some of you will have other more efficient means of working this out
I
> figure, if it can pull 5 times its weight, that this equated to 5 times
the
> speed at its current weight.
>
> As this unit is designed to run full time for 5 hours from the factory
this
> would equate roughly to a speed of 60 kph and a range of 300k's.
>
> So here you guys are talking mega amp controllers and ranges between
charges
> of a fraction of this number so im thinking I have something wrong here
with
> my math's or my basis.
>
> I decided to approach this from a second angle and measure the draw of
> starting accelerating and cruising and my numbers for this are 5, 55 and
30
> amps, the original battery pack was rated at 156 amp hours and 30 into 150
> goes 5 times, so this still runs for 5 hours and the only thing hanging in
> the breeze is just how fast I can make it go pulling the car without
> increasing the draw.
>
> This brings me to gearing which most of the electric cars ive come across
> don't seem to have, with a petrol engine you use a lot of pedal to get it
to
> speed and electric cars seem to be set to do this all the time, when, if
the
> gears are set correctly once speed has been attained, I cant see why the
low
> draw when this unit is starting can not be used to maintain the speed
along
> with the lower gear for climbing hills, so the batteries don't get
depleted
> in a few minutes of hill work.
>
> So if I double my speed I lose half the duration and still end up with
> around 250 k's of range, for those of you working in miles that's 50 miles
> per hour for 2.5 hours, 150 odd miles per charge still, yet none of you
here
> are talking this sort of efficiency and to be honest I was expecting to
find
> that I would get to work which is 25 k's from home and have to charge at
> work to get home again.
>
> What am I missing here ? Why does this seem so much better than I expected
?
>
> As I see it the final compromise is the best speed possible for the least
> amp draw yet lots of people are talking 1 and 2k amp controllers, does
> anyone have a chart that shows the amp draw for a given vehicle weight at
> various speeds ?
>
> thanx
>
> Garry Stanley
>
> Cable.net.nz
>
>
--- End Message ---
--- Begin Message ---
BIKER BEWARE SMOKE AHEAD At 8am today the currenteliminator lead the pack For
the first qt. mile of the Laveen bike challenge.A 500 hundred foot burnout
was the go flag for over a thousand bikes. This event which includes a BQ
will attrack over 50000 people today,lots of exposure for my EV.We have been
the starter for years now. DENNIS
KILL A WATT BERUBE
--- End Message ---
--- Begin Message ---
The Nedra> OUTLAW < Dennis KILL A WATT will also just happen to be at the
VEGAS dragstrip but racing the ICEs.Sure wish the NETGAIN folks would show up
with there WARP MOTORS , NASA CAPS,an NEW RECORD.After I bracket race the
ICEs,I would like to exerise the pack one more time against an EV. MATCH RACE
ANYONE???? DENNIS KILL A WATT BERUBE
--- End Message ---
--- Begin Message ---
Hi Ken,
Where can those Honeywell dc current sensors and electronics be procured
?
How much would they cost ?
How accurate is the equipment ?
What is the max current this equipment can measure ?
What are the part numbers of thes equipment ?
Sounds like alot lighter then using three large heavy bulky brass shunts
:-).
Thanks.
Menlo Park III,
Bill, Glastonbury, CT
On Sat, 08 Feb 2003 22:14:43 -0800 Ken Lange <[EMAIL PROTECTED]> writes:
> I've been using dc current sensors from Honeywell
> in my car. I have one to sense the battery current,
> one for the motor current, and a third to sense the
> charging current. They have worked well for the 3
> years I've been driving the car. They are small and
> require no connections to the battery pack; thus
> they give you complete isolation. The downside
> is that they require some extra electronics to
> process the signals. I use the signals to drive
> gauges on the dash as well as the emeter.
>
> The Zivan battery smoother also uses the
> Honeywell current sensor.
>
> Best regards,
> Ken
________________________________________________________________
Sign Up for Juno Platinum Internet Access Today
Only $9.95 per month!
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--- End Message ---
--- Begin Message ---
Hi Garry
>
> In my garage I have a Mclaren m6gt replica body shell that looks like its
> going to be my first ev car project.
What are you going to do for wheels tranny ect, Is this going on a frame?
What is the ecpected weight (in lbs) of body/frame?
> I have an electric pushbike conversion and an electric motorbike
conversion
> I have done, so I have a basic grasp of how this all works and what breaks
> and what overheats.
Good place to start
> My power plant for this looks like its going to come from a Lansing bagnal
> toer which is basically a forklift without forks.
>
> Its 48 volts and the panel is rated at 205 amps and assuming the motor can
> handle this I calculate from this that I have a motor around 12 horsepower
> (allowing a margin for safety on the control panel).
Will need to know how fast your planning on going and about the weight of
the car.
> To determine if this was a good unit for a conversion I attached a 2000 kg
> load to it and dragged it up the road, it completed this effortlessly,
> indicating that if it can pull far more than its going to in a car, that
it
> will pull the car faster than the 12 kph it currently runs at.
>
> While some of you will have other more efficient means of working this out
I
> figure, if it can pull 5 times its weight, that this equated to 5 times
the
> speed at its current weight.
It dosn't really work that way . If you have a car that is going 50 mph and
you double the power the car will probable go 65mph at 2 times the power not
100 mphs.1/2 the weight don't make it go twice as fast ether. We could look
at it this way if we're going 50mph's and slow down to 25 we'll be using a
lot less that 1/2 the power , probable more like 1/4 the power.
> As this unit is designed to run full time for 5 hours from the factory
this
> would equate roughly to a speed of 60 kph and a range of 300k's.
> So here you guys are talking mega amp controllers and ranges between
charges
> of a fraction of this number so im thinking I have something wrong here
with
> my math's or my basis.
The mega amp controllers are just for spinning the wheels on the pavement
( a funny American pass time ) The amout of amps used to go down the road is
quite a bit less.
> I decided to approach this from a second angle and measure the draw of
> starting accelerating and cruising and my numbers for this are 5, 55 and
30
> amps, the original battery pack was rated at 156 amp hours and 30 into 150
> goes 5 times, so this still runs for 5 hours and the only thing hanging in
> the breeze is just how fast I can make it go pulling the car without
> increasing the draw.
would be nice but I don't think so , we need more info as above
> This brings me to gearing which most of the electric cars ive come across
> don't seem to have, with a petrol engine you use a lot of pedal to get it
to
> speed and electric cars seem to be set to do this all the time, when, if
the
> gears are set correctly once speed has been attained, I cant see why the
low
> draw when this unit is starting can not be used to maintain the speed
along
> with the lower gear for climbing hills, so the batteries don't get
depleted
> in a few minutes of hill work.
>
> So if I double my speed I lose half the duration and still end up with
> around 250 k's of range, for those of you working in miles that's 50 miles
> per hour for 2.5 hours, 150 odd miles per charge still, yet none of you
here
> are talking this sort of efficiency and to be honest I was expecting to
find
> that I would get to work which is 25 k's from home and have to charge at
> work to get home again.
>
> What am I missing here ? Why does this seem so much better than I expected
?
>
> As I see it the final compromise is the best speed possible for the least
> amp draw yet lots of people are talking 1 and 2k amp controllers, does
> anyone have a chart that shows the amp draw for a given vehicle weight at
> various speeds ?
>
> thanx
>
> Garry Stanley
>
> Cable.net.nz
>
>
--- End Message ---
--- Begin Message ---
It is so nice to be able to say when people ask how fast do EV's go "
There's some that will go over 100 mph's in the 1/4 " Then tell them to
look in the EV album at the Current Eliminator . Of course it would me nicer
to say "Mine will do over 100 " but for now I'm just a name dropper.
Keep up the good work
Steve Clunn
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Sunday, February 09, 2003 8:26 AM
Subject: Re: Current Eliminator News(3 more days)
> Another weekend at the races,the currenteliminator dragster ran 5 times on
> friday nite at Firebird raceway.ETs were 10.48 10.46 10.431 10.411 an
10.40
> .MPH#s 125 on all but one of the runs.These runs happened in a 90 minute
time
> frame.My charging time between runs using my 15kw3phase Miller welder
genset
> was13minutes.I had both my series charger and my design micro charger
system
> hooked to the car at the same time(micro charger capable of max31amps
> min..01) I am trying to set the car up for bracket racing,so a fast
> turnaround must be practiced.These easy on the battery pack an car runs
were
> with the batts.charged to about 80% capacity.
> DAY TWO Speedworld Motorplex Six more runs with the ETs
> 11.57 to11.63 an still the MPHs at 125.A slow et with hi mph will really
> throw the ICE bracket racers off.My goal 11,80 at 135mph.with a throttle
stop
> at 1100feet for 100feet before the car turns back on til the end of the
qt.
> mile.This will confuse the bumper racers.Charging times were limited to 13
> minutes again.Otmars ZILLA controller ran perfectly with just air
cooling(at
> these easy ets motor amps are less than 1000amps)There are times I may
have
> to wait up to an hour in the stageing lanes without working on the car
thus I
> had to know if the car can be coninsent without ice water cooling.It
Is....I
> do have to work on geting the Ets closer together.
> DAY three NEXT POST
> Dennis KILL A WATT BERUBE Worlds Quickest EV currenteliminator.net
>
>
--- End Message ---
--- Begin Message ---
This is the prime reason PFC50s have 1/2 bridge PowerEX modules, and PFC20s
have ISO tops. Been there done that, got the Scars!!!. The device math on
all my stuff right now is NOTHING paralleled. But you can parallel complete
charger units.
The BAD part about the math is a single ISO top is $25 bucks for 80 amps.
The TO-264 devices is 6-8 bucks each, same chip. So right off the devices
cost 3x for the same Die in different packages. Also Damon and Otmar use non
isolated devices, and have to electrically isolate BAT + from the heat sink.
This is a real effort.
Damon and Otmar have some rather different views. Otmar and I have had the
same basic concepts since before DCP existed. Damon has the high volume
production practice. I deferred to his wisdom. Maybe I should have been more
stubborn.
I am having a blast putting to use my latent copper Butcher practice. And
Otmar has been warning me about thermal issues.... and behold he's right.
Getting 100 amps out of a PFC20 power stage... will be a thermal challenge.
Relax it's a R&D unit for 120 only input and 48 volts output.
Also a brutal note Isotops are the only power device package that I have
been able to get rated maximum thermal outputs from. I think Ot's stuff
with a copper water cooled heatsink gets there also. There is just no way
you can do this with Damon's Stack up. At greater than about %30 load, your
hang time is governed by the thermal mass of the device. On Ot's and my
stuff the transfer is so fast that we can rely on the thermal mass of the
alum and copper. Well it's a complicated math that varies dramatically
according to the current being passed. Hang time, is a hard item to deal
with. Chargers have to hang at full power until the battery pack gets
filled. DCPs hang until the heatsink gets to 90 Deg C, then taper back.
Zillas can hang at full power for ..... along time. They have the best
cooling.
Funny data point the PFC50s use the same heatsink as the DCPs use....
kinda a legacy for me. I am making 11 Plus Kw of charge current, and I am
now out of overhead on the heat sink. Works nice at 50 amps and 75 Deg F. a
bit Iffy at 75 amps and 100 Deg F. NOT gonna cut it at 100 amps and 120 Deg
F. Damon once said that the Raptors made something like 2250 watts of waste
heat at 1200 amps. I am making about 800 watts of waste heat, depending on
a LOT of variables. So full power on a Raptor is something like 5 seconds
and tapers to less than 1000 amps in about 10 seconds. I remember claiming
over 1000 amps for 10 seconds. I dunno if I ever got this. I know I still
can rail a 1000 amp E-meter at will in the Fiero.
Lee Hart wrote:
> Rich Rudman wrote:
> > Have you ever been inside a DCP controller? The buss bars are 10
> > inches long, and precision drilled, and are soldered all at once
> > with a 35 lbs chunk of copper heated to 550 Deg F. You do this 3
> > times.... once for each buss Bar.
>
> Yes, I've seen it. I've always wondered why Damon did it this way. Yes,
> it produces the lowest possible electrical and thermal resistance. But
> it also makes it very hard to build, and impossible to repair!
>
> But, this part of the construction could be considerably simplified with
> only a small loss in performance.
>
> Better still, use modules or Isotops. They cost more, but boy, do they
> make assembly easy!
> --
> 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
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "1sclunn" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Sunday, February 09, 2003 1:08 PM
Subject: Re: thoughts and questions
>
>
>
>
> Hi Garry
> >
> > In my garage I have a Mclaren m6gt replica body shell that looks like
its
> > going to be my first ev car project.
>
> What are you going to do for wheels tranny ect, Is this going on a frame?
> What is the ecpected weight (in lbs) of body/frame?
>
> > I have an electric pushbike conversion and an electric motorbike
> conversion
> > I have done, so I have a basic grasp of how this all works and what
breaks
> > and what overheats.
>
> Good place to start
>
> > My power plant for this looks like its going to come from a Lansing
bagnal
> > toer which is basically a forklift without forks.
> >
> > Its 48 volts and the panel is rated at 205 amps and assuming the motor
can
> > handle this I calculate from this that I have a motor around 12
horsepower
> > (allowing a margin for safety on the control panel).
>
> Will need to know how fast your planning on going and about the weight of
> the car.
>
>
> > To determine if this was a good unit for a conversion I attached a 2000
kg
> > load to it and dragged it up the road, it completed this effortlessly,
> > indicating that if it can pull far more than its going to in a car, that
> it
> > will pull the car faster than the 12 kph it currently runs at.
> >
> > While some of you will have other more efficient means of working this
out
> I
> > figure, if it can pull 5 times its weight, that this equated to 5 times
> the
> > speed at its current weight.
>
> It dosn't really work that way . If you have a car that is going 50 mph
and
> you double the power the car will probable go 65mph at 2 times the power
not
> 100 mphs.1/2 the weight don't make it go twice as fast ether. We could
look
> at it this way if we're going 50mph's and slow down to 25 we'll be using a
> lot less that 1/2 the power , probable more like 1/4 the power.
>
>
> > As this unit is designed to run full time for 5 hours from the factory
> this
> > would equate roughly to a speed of 60 kph and a range of 300k's.
>
>
> > So here you guys are talking mega amp controllers and ranges between
> charges
> > of a fraction of this number so im thinking I have something wrong here
> with
> > my math's or my basis.
>
> The mega amp controllers are just for spinning the wheels on the pavement
> ( a funny American pass time ) The amout of amps used to go down the road
is
> quite a bit less.
>
>
> > I decided to approach this from a second angle and measure the draw of
> > starting accelerating and cruising and my numbers for this are 5, 55 and
> 30
> > amps, the original battery pack was rated at 156 amp hours and 30 into
150
> > goes 5 times, so this still runs for 5 hours and the only thing hanging
in
> > the breeze is just how fast I can make it go pulling the car without
> > increasing the draw.
> would be nice but I don't think so , we need more info as above
>
>
> > This brings me to gearing which most of the electric cars ive come
across
> > don't seem to have, with a petrol engine you use a lot of pedal to get
it
> to
> > speed and electric cars seem to be set to do this all the time, when, if
> the
> > gears are set correctly once speed has been attained, I cant see why the
> low
> > draw when this unit is starting can not be used to maintain the speed
> along
> > with the lower gear for climbing hills, so the batteries don't get
> depleted
> > in a few minutes of hill work.
> >
> > So if I double my speed I lose half the duration and still end up with
> > around 250 k's of range, for those of you working in miles that's 50
miles
> > per hour for 2.5 hours, 150 odd miles per charge still, yet none of you
> here
> > are talking this sort of efficiency and to be honest I was expecting to
> find
> > that I would get to work which is 25 k's from home and have to charge at
> > work to get home again.
> >
> > What am I missing here ? Why does this seem so much better than I
expected
> ?
> >
> > As I see it the final compromise is the best speed possible for the
least
> > amp draw yet lots of people are talking 1 and 2k amp controllers, does
> > anyone have a chart that shows the amp draw for a given vehicle weight
at
> > various speeds ?
> >
> > thanx
> >
> > Garry Stanley
> >
> > Cable.net.nz
> >
> >
>
--- End Message ---
--- Begin Message ---
More like 176 feet. Lawrence Rhodes....
----- Original Message -----
From: "Jessica & Donald Jansen & Crabtree" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Sunday, February 09, 2003 7:14 AM
Subject: Re: Kick in the pants 0 to 60 in 2.5 seconds.
> Hi-
> is that 60mph or 60ft.
> F.T.
>
> Lawrence Rhodes wrote:
>
> > http://www.kelseyville.com/biodsl/bike.htm This is the answer to the
what
> > if of a 72v Motorcycle. Lawrence Rhodes......
>
>
--- End Message ---
--- Begin Message ---
Welcome, Garry! Sounds like a fun project!
Garry Stanley wrote:
> In my garage I have a Mclaren m6gt replica body shell that looks
> like its going to be my first ev car project...
> My power plant for this looks like its going to come from a Lansing
> bagnal toer which is basically a forklift without forks. Its 48 volts
> and the panel is rated at 205 amps and assuming the motor can handle
> this I calculate from this that I have a motor around 12 horsepower
I'd estimate it this way: The 48v batteries would sag to 40v under a 205
amp load, so 40v x 205a = 8200 watts is going into the motor. It will be
around 80% efficient, so 8200w x 0.8 = 6560w comes out. 6560w / 746w/hp
= 8.8 horsepower.
If you put this motor in an EV, you can run it at as much as double the
voltage (80v). That lets you get about double the horsepower, which will
be fine for a light efficient car.
The stock motor's 205a rating is probably based on 1 hour of operation
at full power. I.e. the motor *just* reaches its maximum temperature
after 1 hour operation at 205 amps. You will probably have a lower
amphour-capacity battery pack such that you couldn't run at 205 amps for
even half an hour. Thus, you can run the motor at higher currents for
less time; say 300 amps for 1/2 hour. That raises your horsepower
another 50%. And of course, these motors are very tough; 500-1000 amps
for a few seconds won't seriously shorten their life, which gives you
breathtaking accelleration (if the batteries and controller can take
it).
> To determine if this was a good unit for a conversion I attached a
> 2000 kg load to it and dragged it up the road, it completed this
> effortlessly... I figure, if it can pull 5 times its weight, that
> this equated to 5 times the speed at its current weight.
What really matters in this test is how much horizontal force the toer
was producing and at what speed. Force x distance = horsepower. If by
"drag" you meant it was on wheels, the force was a lot less than 2000
kg.
> As this unit is designed to run full time for 5 hours from the
> factory this would equate roughly to a speed of 60 kph and a range
> of 300k's.
Ah, but it doesn't run at full power for the full 5 hours. The peak load
is 205 amps, but the average is a lot less.
> I decided to approach this from a second angle and measure the draw
> of starting accelerating and cruising and my numbers for this are 5,
> 55 and 30 amps, the original battery pack was rated at 156 amp hours
> and 30 into 150 goes 5 times, so this still runs for 5 hours and the
> only thing hanging in the breeze is just how fast I can make it go
> pulling the car without increasing the draw.
Cruising, 48v x 30a = 1440w. 1440w x 0.8 / 746w/hp = 1.5 horsepower.
Your full-size car isn't going to go much faster than the toer on 1.5
hp.
> with a petrol engine you use a lot of pedal to get it to speed and
> electric cars seem to be set to do this all the time
This is just the throttle response: the horsepower you get vs.
accellerator pedal position. This curve can be tailored to have any
relationship you like. Car makers play games with it to make a car "feel
powerful". For example, a 100hp engine goes from 0 to 90hp when the
accellerator pedal is pushed 1/4 of the way down. This implies that
there is a lot more power if you push the pedal further, but there is
not.
Electric vehicle controllers are generally designed for forklifts and
other industrial controls and don't play this game. Horsepower is
linearly related to accellerator pedal position.
> if the gears are set correctly once speed has been attained, I can't
> see why the low draw when this unit is starting can not be used to
> maintain the speed along with the lower gear for climbing hills, so
> the batteries don't get depleted in a few minutes of hill work.
It takes a certain amount of horsepower to go a certain speed. The
gearing doesn't change this; it only changes the motor speed. The
efficiency of an electric vehicle only changes slightly depending on
what gear you are in (as long as you don't bump up against its
voltage/rpm or current/torque limits).
So, if you are driving along at (say) 30 mph, it takes the same battery
current in 1st, 2nd, 3rd, or 4th gear. There are slight differences due
to transmission efficiency in the different gears, or because the motor
has an internal fan that uses more power at higher rpms, or because in
the higher gears the motor is running at lower voltage and higher
current, so I^2R losses are more.
This approximation only breaks down if you are driving so fast that the
motor would overspeed if kept in 1st gear (or that you have run out of
battery voltage to make the motor go this fast), or if you are driving
so slow in 4th gear that the motor overheats from excessive current at
low voltage (or that the controller can't supply this much current).
> So if I double my speed I lose half the duration
Once you get fast enough to where wind resistance begins to be a factor,
horsepower requirements go up as a SQUARE of the speed. I.e. 2x faster
requires 4x the horsepower.
> As I see it the final compromise is the best speed possible for
> the least amp draw yet lots of people are talking 1 and 2k amp
> controllers.
You see a lot of posts from the racing crowd. They are the ones using
the 1000-amp controllers and high battery voltages. You don't need this
for daily commuting -- but it sure is fun! :-)
> does anyone have a chart that shows the amp draw for
> a given vehicle weight at various speeds?
Certainly. I have a Renault LeCar EV conversion. This is a small car
that weighs about 2400 lbs, and has a 132v 40ah (at the 1-hour rate)
battery pack, Advanced DC L91 motor (rated 96v 150a for 1 hour), and
Curtis 1231C controller (rated 144v, 600a max). Battery current draw at
various constant speeds is:
mph 25 30 35 40 45 50 55 60
amps 22 28 36 45 56 70 86 105
--
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
--- End Message ---
--- Begin Message ---
http://www.mastertexts.com/Appleton_Victor/Tom_Swift_and_his_Electric_Runabo
ut/Chapter00003.htm
Lawrence Rhodes........
--- End Message ---
--- Begin Message ---
Bruce EVangel Parmenter wrote:
> Following the GodZilla movie theme, the smaller version
> of GodZilla was, Baby GodZilla. So would Otmar name this
> lower powered controller:
>
> -baby Zilla,
> -lil Zilla, or
> -Zilla-lite?
Or if "daddy" was GodZilla, maybe JesusZilla :-)
--
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
--- End Message ---
--- Begin Message ---
Seth wrote:
> The local surplus place has copper cooling coils made of 5/8" tube.
> They are 8" inside diameter and 12-14 inches long. They look like you
> could slide them on a motor. $50 each, I think. I don't have an 8"
> motor, but it looks like a visually interesting experiment waiting
> to happen.
Except that almost all the heat is being generated in the brushes and
armature windings. They don't lend themselves to liquid cooling. Cooling
the outside of the case (the field winding) does little good.
When people have wanted to liquid cool brushed DC motors, they use a
hollow shaft and pump the coolant throught it. This of course means
rotating seals. Or, in a few specialized application (like torpedo
motors) they have run the motors submerged in liquid.
I don't know if anyone has done it, but a heat pipe could get the heat
out of brushes.
--
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
--- End Message ---
--- Begin Message ---
Its that time of the month again.
We will be talking about New Places to meet, (if we get much bigger)
New members with "Spice" aka Segway 2 wheeler
New NEV legislative initiatives in Olympia WA. coming up
OT - BioDiesel
Another show at Crossroads Mall
and much much more.....
--
Steven S. Lough, Pres.
Seattle EV Association
6021 32nd Ave. N.E.
Seattle, WA 98115-7230
Day: 206 396-9189
Eve: 206 524-1351
e-mail: [EMAIL PROTECTED]
web: http://slough1.home.mindspring.com/seva.html
--- End Message ---
--- Begin Message ---
DemiGod?
I'm sure you can set the current limit (battery and or motor) to fit
your purposes, then do your best to air cool the baseplate. But you're
probably interested in lower cost per amp.
Air-cooled designs would tend toward a relatively large footprint
(compared to volume, like Auburn) but you can make up for it by
increasing air flow rate. I'm talking about "base rated" designs, where
the heat is pulled out thru a base plate, as opposed to "wetted" designs
like a PC where the air scrubs the components directly. The heat sink
can extend beyond the footprint of the controller, though less bang for
buck out there.
- GT
> -----Original Message-----
> From: Bruce EVangel Parmenter [mailto:[EMAIL PROTECTED]]
> Sent: Saturday, February 08, 2003 6:12 PM
> To: [EMAIL PROTECTED]
> Subject: Air Cooled Controllers
>
>
> All this talk of the Zilla had me thinking ...
>
> What is available as a 'drop in' for the
> air cooled Cursit 1221 (a-z) controller, or
> the air cooled Auburn controllers?
>
> Are there any with regen?
>
> Lower powered, lower cost, air cooled controllers would
> not hit my pack as hard, I would not be paying for the
> power I do not use, and I would not have to be concerned
> with any plumbing for liquid cooling.
>
> ...
> My other thought is what if Otmar made a lower amperage
> controller. His 1000 amp controller is called Zilla.
>
> Following the GodZilla movie theme, the smaller version
> of GodZilla was, Baby GodZilla. So would Otmar name this
> lower powered controller:
>
> -baby Zilla,
> -lil Zilla, or
> -Zilla-lite?
>
>
> =====
> ' ____
> ~/__|o\__
> '@----- @'---(=
> . http://geocities.com/brucedp/
> . EV List Editor & RE newswires
> . (originator of the above ASCII art)
> =====
>
> __________________________________________________
> Do you Yahoo!?
> Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
> http://mailplus.yahoo.com
>
--- End Message ---
--- Begin Message ---
It's unlikely that this bike does 0 - 60 mph in 25 seconds. I suspect that
this fellow misread his time slip. There is a figure for 60 foot ET that
would likely be 2.5 seconds for this bike.
_ /| Bill "Wisenheimer" Dube'
\'o.O' <[EMAIL PROTECTED]>
=(___)=
U
Check out the bike -> http://www.KillaCycle.com
--- End Message ---
--- Begin Message ---
Following the GodZilla movie theme, the smaller version
of GodZilla was, Baby GodZilla. So would Otmar name this
lower powered controller:
-baby Zilla,
-lil Zilla, or
-Zilla-lite?
Zillette?
Tad-Zilla?
Milli-Zilla?
=====
' ____
~/__|o\__
'@----- @'---(=
. http://geocities.com/brucedp/
. EV List Editor & RE newswires
. (originator of the above ASCII art)
=====
__________________________________________________
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
http://mailplus.yahoo.com
_ /| Bill "Wisenheimer" Dube'
\'o.O' <[EMAIL PROTECTED]>
=(___)=
U
Check out the bike -> http://www.KillaCycle.com
--- End Message ---
--- Begin Message ---
Where these runs done with NiCd batteries?
If so, do you have more information on the batteries?
Thanks,
Rod
[EMAIL PROTECTED] wrote:
Another weekend at the races,the currenteliminator dragster ran 5 times on
friday nite at Firebird raceway.ETs were 10.48 10.46 10.431 10.411 an 10.40
.MPH#s 125 on all but one of the runs.These runs happened in a 90 minute time
frame.My charging time between runs using my 15kw3phase Miller welder genset
was13minutes.I had both my series charger and my design micro charger system
hooked to the car at the same time(micro charger capable of max31amps
min..01) I am trying to set the car up for bracket racing,so a fast
turnaround must be practiced.These easy on the battery pack an car runs were
with the batts.charged to about 80% capacity.
DAY TWO Speedworld Motorplex Six more runs with the ETs
11.57 to11.63 an still the MPHs at 125.A slow et with hi mph will really
throw the ICE bracket racers off.My goal 11,80 at 135mph.with a throttle stop
at 1100feet for 100feet before the car turns back on til the end of the qt.
mile.This will confuse the bumper racers.Charging times were limited to 13
minutes again.Otmars ZILLA controller ran perfectly with just air cooling(at
these easy ets motor amps are less than 1000amps)There are times I may have
to wait up to an hour in the stageing lanes without working on the car thus I
had to know if the car can be coninsent without ice water cooling.It Is....I
do have to work on geting the Ets closer together.
DAY three NEXT POST
Dennis KILL A WATT BERUBE Worlds Quickest EV currenteliminator.net
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--- Begin Message ---
I don't know about "most" forklift motors, but I've seen a few that work
great in EV applications. I used one in my electric dragbike and set a 120
volt NEDRA record that still stands. And Brian Hall has a little red Honda
Civic running a forklift motor.
The forklift motor I had in my bike was well made with a nicely balanced
armature, and it had adjustable brush timing. It was rated at 105 amps and
2000 rpm for an hour, 4.5 hp. I ran it at 120 volts on my bike and around
400 amps. Based on the acceleration (14.25 seconds, 92mph, and about 550
lbs total weight) I think I was getting about 35 hp at the rear wheels. It
was a pretty short duty cycle, though. And, I can't remember what rpm's it
was turning, but probably not more than about 3000 or 4000.
Henry Deaton
At 08:33 AM 2/9/2003 -0800, you wrote:
Hi, Garry - and welcome to the list!
You've got one little problem in your calculations, and that's called
overspeeding the motor. If you can find a transmission with a high enough
gear ratio, you will be alright - but most forklift motors aren't made to
have a high RPM, and your motor will spontaneously disassemble if you over
speed it.
Joseph H. Strubhar
E-Mail: [EMAIL PROTECTED]
Web: www.gremcoinc.com
----- Original Message -----
From: "garry" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Sunday, February 09, 2003 7:21 AM
Subject: thoughts and questions
> Hi Folks,
>
> I'm a learner in the ev field so please forgive me if I don't know what im
> talking about or simply seem misinformed.
>
> I have always wanted to build a car, but never really got to do more than
> customize an existing car.
>
> In my garage I have a Mclaren m6gt replica body shell that looks like its
> going to be my first ev car project.
>
> If you don't know what this is you will probably be familiar with the Ion
ev
> and this is the same as that, full fiberglass body on a space frame.
>
> I have an electric pushbike conversion and an electric motorbike
conversion
> I have done, so I have a basic grasp of how this all works and what breaks
> and what overheats.
>
> My power plant for this looks like its going to come from a Lansing bagnal
> toer which is basically a forklift without forks.
>
> Its 48 volts and the panel is rated at 205 amps and assuming the motor can
> handle this I calculate from this that I have a motor around 12 horsepower
> (allowing a margin for safety on the control panel).
>
> To determine if this was a good unit for a conversion I attached a 2000 kg
> load to it and dragged it up the road, it completed this effortlessly,
> indicating that if it can pull far more than its going to in a car, that
it
> will pull the car faster than the 12 kph it currently runs at.
>
> While some of you will have other more efficient means of working this out
I
> figure, if it can pull 5 times its weight, that this equated to 5 times
the
> speed at its current weight.
>
> As this unit is designed to run full time for 5 hours from the factory
this
> would equate roughly to a speed of 60 kph and a range of 300k's.
>
> So here you guys are talking mega amp controllers and ranges between
charges
> of a fraction of this number so im thinking I have something wrong here
with
> my math's or my basis.
>
> I decided to approach this from a second angle and measure the draw of
> starting accelerating and cruising and my numbers for this are 5, 55 and
30
> amps, the original battery pack was rated at 156 amp hours and 30 into 150
> goes 5 times, so this still runs for 5 hours and the only thing hanging in
> the breeze is just how fast I can make it go pulling the car without
> increasing the draw.
>
> This brings me to gearing which most of the electric cars ive come across
> don't seem to have, with a petrol engine you use a lot of pedal to get it
to
> speed and electric cars seem to be set to do this all the time, when, if
the
> gears are set correctly once speed has been attained, I cant see why the
low
> draw when this unit is starting can not be used to maintain the speed
along
> with the lower gear for climbing hills, so the batteries don't get
depleted
> in a few minutes of hill work.
>
> So if I double my speed I lose half the duration and still end up with
> around 250 k's of range, for those of you working in miles that's 50 miles
> per hour for 2.5 hours, 150 odd miles per charge still, yet none of you
here
> are talking this sort of efficiency and to be honest I was expecting to
find
> that I would get to work which is 25 k's from home and have to charge at
> work to get home again.
>
> What am I missing here ? Why does this seem so much better than I expected
?
>
> As I see it the final compromise is the best speed possible for the least
> amp draw yet lots of people are talking 1 and 2k amp controllers, does
> anyone have a chart that shows the amp draw for a given vehicle weight at
> various speeds ?
>
> thanx
>
> Garry Stanley
>
> Cable.net.nz
>
>
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