EV Digest 5211
Topics covered in this issue include:
1) Re: Can a generator be fitted on an EV, powered by the drivetrain?
by "Peter VanDerWal" <[EMAIL PROTECTED]>
2) Re: 35 mph @ 150 amps and 48 volts
by "Peter VanDerWal" <[EMAIL PROTECTED]>
3) Re: Brakes .. Vacuum to manual
by "Peter VanDerWal" <[EMAIL PROTECTED]>
4) Re: It's the energy density problem
by Victor Tikhonov <[EMAIL PROTECTED]>
5) Re: Newbie question: Multiple cheap motors to drive a vehicle
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
6) Re: Subaru showing of an electric car at the Canadian International Auto
Show in Toronto
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
7) Re: Trip in Emergency Only
by "Peter VanDerWal" <[EMAIL PROTECTED]>
8) Re: Trip in Emergency Only
by "Peter VanDerWal" <[EMAIL PROTECTED]>
9) signoff ev
by spidercats <[EMAIL PROTECTED]>
10) Re: Can a generator be fitted on an EV, powered by the drivetrain?
by "Roland Wiench" <[EMAIL PROTECTED]>
11) Re: (probably dumb) rapid charge idea.
by Fortunat Mueller <[EMAIL PROTECTED]>
12) Re: Can a generator be fitted on an EV, powered by the drivetrain?
by Lee Hart <[EMAIL PROTECTED]>
13) RE: precharge circuit
by Fortunat Mueller <[EMAIL PROTECTED]>
14) Re: Trip in Emergency Only
by Lee Hart <[EMAIL PROTECTED]>
15) Re: It's the energy density problem (was: Battery charging in
only5minutes)
by Lee Hart <[EMAIL PROTECTED]>
16) Re: Newbie question: Multiple cheap motors to drive a vehicle
by P C <[EMAIL PROTECTED]>
17) Re: Trip in Emergency Only
by "Mark Grasser" <[EMAIL PROTECTED]>
18) Re: Trip in Emergency Only
by "Dale Curren" <[EMAIL PROTECTED]>
19) RE: Newbie question: Multiple cheap motors to drive a vehicle
by P C <[EMAIL PROTECTED]>
20) new tech papers once again available
by David Brandt <[EMAIL PROTECTED]>
21) Re: EV digest 5210
by Seth Allen <[EMAIL PROTECTED]>
--- Begin Message ---
> Is it at all possible for a generator or alternator to run off the motion
> of the vehicle itself?
Yup you sure can. You can also tie and anchor to the EV and throw it out
the back when you're driving down the road, it has pretty much the same
effect.
Ok, let's take a look at this. The universe we live in has a thing called
friction, which I'm sure you've heard of. Friction shows up in all kinds
of places. There is friction in the bearings, their is friction in the
air moving past/over the vehicle, their is even friction in the tires
rolling down the road. All of this friction converts motion into heat and
in the process tries to slow down the vehicle.
There is a really easy test to see this happen. Get in a car and
accelerate up to say 50 mph. Then put it in neutral and coast. What
happens? The car slows down right?
In order to stay at 50 mph you have to add enough energy to overcome the
energy lost to friction. This is where the motor comes in. This energy
that the motor is producing isn't free energy that available for other
things, it's ALL being used up to keep the vehicle moving.
If you want to add something else then the motor has to produce MORE
energy to power it.
Now lets take a look at the generator. As we've just shown their isn't
any free energy hanging around to power the generator, so we have to get
the power from somewhere. In this case that somewhere is the drive motor.
Now we have other losses in the vehicle besides friction that we haven't
talked about yet. The motor has losses; electrical losses, mechanical
losses, and magentic losses. The generator has these same kinds of
losses.
So the net result is that in order to get 1 watt out of the generator we
have to put an extra 2 watts into the motor (the 1 watt that we get out of
the generator plus another 1 watt for losses)
So if we hook this up and try to charge our batteries while driving, we
actually end up running them down faster.
Now there are a couple practical reasons to add a generator.
One of them, as others have mentioned, is to help slow the vehicle down
when you want to. Every watt of energy the generator produces is about 1
1/2 watts of energy it takes away from the motion of the vehicle. The
more watts you take out, the faster the vehicle slows down. This is
called regenerative braking. Since we're not using the drive motor to
push the car when we're slowing down, we can put this energy back into the
pack.
Most folks who do this don't actually add a generator however; they just
change the way the motor operates and use it as a generator.
Another way some people use a generator is to keep the 12V battery used
for lights and accessories charged up. Most folks use a DC-DC converter
charge the accessory battery from the main battery pack. However, DC-DC
converters are somewhat expensive, wo some folks use a standard car
alternator driven by the drive motor instead. It's cheaper, but has a
couple disadvantage. It's not as effecient as the DC-DC (the DC-DC might
take 1.2 watts out of the main pack to put 1 watt into the acc battery,
where the Alternator will take 2 watts), and the alternator stops working
when you come to a stop unless you idle the drive motor (which is REALLY
inefficient)
Welcome to the list.
--
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 ---
Sounds about right, perhaps a triffle high.
FWIW the average small car requires approx 10 hp to go 50 mph.
> This is for a 4 door Geo in 3 rd gear.... V x A = 7200 Watts ??
> Is this in the ballpark or should I be able to do much better.
>
> 1 st - 15 mph 2nd 25 mph 3rd 35 mph 4th 45 mph
>
> Will measure 4th and 5th gear amps tomorrow
>
--
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 ---
> Can the diaphram be broken/ punctured to make manual brakes that are
> easier to push than just removing the line ?
>
With the line open, you aren't working against the diaphram, you are
working against the return spring. You could probably remove the spring
and replace it with a weaker one, or even eliminate it if their is another
spring on the pedal.
--
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 ---
Yes they do, but extract pitiful amount of joules gasoline
possess.
Victor
Mike Ellis wrote:
Fuel cells do this now.
-Mike
On 2/24/06, Victor Tikhonov <[EMAIL PROTECTED]> wrote:
Mike & Paula Willmon wrote:
Remember though that the volumetric energy that you refer to for
gasoline is
heat energy.
No. Energy is energy, so many joules in a liter of gasoline, period.
It just happens that today it can only be extracted by burning it
(so as heat), but if someone years from now discovers a way to
efficiently convert chemical energy of unburned cold gasoline
to electrical energy (similar to photo-cells converting light energy)
without burning it, than heating won't be an issue at all.
That's the theory, which may or may not practically happen though.
Victor
--- End Message ---
--- Begin Message ---
Extra motors are not redundent. All the fast EV's have two motors or more.
Lawrence Rhodes....
----- Original Message -----
From: "ziperle" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, February 24, 2006 5:06 PM
Subject: Newbie question: Multiple cheap motors to drive a vehicle
I just read the EV article in Make magazine and it got me thinking
real hard about doing an EV conversion. There is a picture of a
Datsun with 3 motors installed that was converted by Tom True and Don
Crabtree. What is the advantage of doing this? Is there any sense in
doing cheap redundant motors and batteries RAIM?
New term maybe - R.edundant A.rray of I. independent or inexpensive
M.otors?
Crazy thought but EVs offer the possibility of driving the vehicle
with redundant systems. The thought I have is kind of like RAID or
JBOD (just a bunch of harddrives) for a computer, and doing this to a
car. If a single component were to fail, the vehicle might be able to
continue moving on the balance of the systems that are still
functioning. Obviously, failover mechanisms would have to be baked
into the design.
For example, a 2 wheeled vehicle with balanced batteries, motors and
controllers. One half of the systems could fail and the car could
continue to move although slower and for a shorter distance. If the
car had 4 wheels and separate controllers and batteries, the car could
theoretically take a 75% component failure and still move.
Other possibilities are to failover some of the systems to extend the
range. For example, a motor fails; the battery and controller could
be engaged onto the still working motor.
Another thought is with a quad system, options exist like performance
mode - run all for systems at the same time. Economy mode could run
on half of the systems (front or rear wheels).
I found some DC treadmill motors cheap and in the 1-2.5hp range
depending on input voltage? An example motor I found is rated
[EMAIL PROTECTED] to [EMAIL PROTECTED] and 5 amps, weighs 14lbs with a large
fly-wheel that would probably be removed.
I know this sounds wimpy compared to the Advanced DC or ETek motors
but does this make any sense for an entry level conversion? I know
there are many other design considerations (donor car, batteries,
controller, etc.) but the motor seems like a good place to start a
design.
Also, does anyone have experience with controllers? Is it easier to
control higher voltage or amperage? I would think that higher voltage
has the advantage of permitting smaller gauge wire and maybe better
efficiency when it comes to voltage drops from impedance and
resistance that are inherent in batteries, motors and controller
components.
Thanks for the advice and opinions.
--- End Message ---
--- Begin Message ---
I've been watching this one for a while. Lets hope Subaru can do what
everyone else can't. Lawrence Rhodes.....
----- Original Message -----
From: "Harris, Lawrence" <[EMAIL PROTECTED]>
To: "EVDL" <[email protected]>
Sent: Friday, February 24, 2006 5:44 PM
Subject: Subaru showing of an electric car at the Canadian International
Auto Show in Toronto
Just read in the local paper that Subaru is showing off their R1E concept
car. It is reported to be 120km/h max and 120 km range (I assume you
can't
have both) using Manganese Lithium-Iron batteries and having a 15 minute
recharge from a single phase 200v outlet. The battery was reported in the
paper to be the 'size of a bread box'
http://autonet.ca/Autoshows/story.cfm?story=/Autoshows/Toronto/2003/12/22/14
23085.html
<http://autonet.ca/Autoshows/story.cfm?story=/Autoshows/Toronto/2003/12/22/1
423085.html>
Lawrence
--- End Message ---
--- Begin Message ---
> It seems unsafe to me. If you're driving at 45-50 mph and determine the
> controller has failed full-on, pushing the brakes all the way to the
> floor will lock the wheels and could cause you to lose control of the
> vehicle. The period before the contactor disengages could be pushing
> the brakes against the full-on motor, which could result in further
> damage.
>
> It could make sense to open the contactor whenever the brakes are
> pressed, but that might wear the contactor to keep engaging/disengaging
> like that.
Well, under normalk circumstances the contactor won't be carrying much, if
any, current. SO it's not so bad.
The controller in my truck has two main contactors, one on to energize the
system and the other one engages when ever the throttle is pressed. It
disengages when you let up on the throttle.
The system is about 15 years old and still looks to be in good shape. Of
course, I've only put about 7-8,000 miles on it...mostly in stop and go
traffic.
>
> Danny
>
> Bill Dennis wrote:
>
>>A few weeks ago, there was a discussion here about where to put the
>>emergency disconnect, for example in the case of controller failure in
>>full-on mode. Someone suggested on the clutch, but someone else said
>> that
>>the break pedal makes more sense, since that's what you'd naturally stomp
>> on
>>in case of emergency.
>>
>>Has anyone looked into the possibility of hooking a high-voltage switch
>> or
>>contactor or breaker up to the brake pedal so that under normal
>>circumstances, when you were just applying the brake in daily use,
>> nothing
>>would get disconnected--but if you really pressed hard or fast on the
>> pedal,
>>the switch would open? Is such a thing even possible?
>>
>>Thanks.
>>
>>Bill Dennis
>>
>>
>
>
--
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 ---
> solution was to use the microswitch in your Curtis potbox to detect
> when the accelerator pedal is not depressed, and use that to open the
> contactor. Lots of "clunk-clunk" noises result, but it should be
> safest because the first thing you do in an emergency is take your foot
> off the gas.
I think this is better than using a switch on the brake. When coasting to
a stop you might alternate between brake and glide, this would have the
contactor cycling on and off, even though it doesn't need to be on.
With the accelerator pedal, the contactor is ONLY on when you need it to
be on.
--
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 ---
signoff ev
--- End Message ---
--- Begin Message ---
Hello Jody,
These are a large unit that is normally used in marine or ships for
generating power for a boat. Some large commercial vehicles use it to power
AC units. A friend of my had one of spare units that they used in there
semi's which I had to overhaul. This was back in 1977 when the car was a
series hybrid. The unit was used off the engine to drive a hydrogen-oxygen
fuel cell which ran a duel fuel engine.
The new cost for the DC/AC unit at that time was just over $1000.00. The 7
kw 120 VAC 60 hz inverter package design for this alternator is another
$1500.00 factory cost. So you have a cost of $2500.00 back in 1975.
The Dynamote Company at 1200 West Nickerson, Seattle WA 98119 makes two
different types of DC-AC inverters. One that drives off the Delco Remy 40S1
Series, type 150, model #1117151 and #1117152, which is pre-wired at factory
for installation with Series "A" inverters.
The other type of inverter is used directly off the battery pack which will
generate 120 VAC 60 hz 7kw which would be prefer over the alternator type,
but would not provide me any addition mechanical REGEN that I need to slow
this car down and I also need at least 80 amps of 15 volts DC at the same
time.
But, I got the whole works for less than $500.00 so I tested it out and its
work good for my application. I can run standard 120 vac heaters, drive
motors and ICE units without any major modifications. If some item goes out,
I can go to any auto parts store to replace it.
I used it mostly for slowing down the EV that acts just like compression
braking coming down a long hill while still generating power to all the
accessories.
I have moved to a new location, so I do not have to drive this hill six
times a day. Maybe once a month now. So the DC-AC inverter off the battery
pack would work better for me, except for one thing, I would need a larger
car to add 6 more AC motors to drive all the accessories I have now. It now
takes drive belt that takes up 2 inches of space to drive all this units.
In 1975, the inverter unit was about 2 cubic feet in size. The new solid
state units are about 1 cubic foot which I have now. It just fits in the
space ahead of the inner fender well up against the front radiator support.
Roland
----- Original Message -----
From: "Jody Dewey" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, February 24, 2006 7:13 PM
Subject: RE: Can a generator be fitted on an EV, powered by the drivetrain?
> Roland,
>
> Who makes your DC and AC combined alternator? Do you have a part number
> and
> a place to get one? That is exactly what I was looking for.
>
> Jody
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Behalf Of Roland Wiench
> Sent: Friday, February 24, 2006 6:50 PM
> To: [email protected]
> Subject: Re: Can a generator be fitted on an EV, powered by the
> drivetrain?
>
>
> Hello John,
>
> I am running a accessory drive off the pilot shaft of the motor, (the
> front
> shaft). The accessory drive includes a alternator-inverter unit that can
> produce 13.5 to 16 volts DC at 145 amps and 120 volts AC 60 hz at 7000
> watts
> at the same time. I can drive all my heating systems and air condition
> units with this unit.
>
> I use to have a industrial Honeywell DC to DC unit that ran all the
> accessories off the main battery pack. In my EV this became very
> dangerous
> in the winter time coming down a steep 3 mile long hill that is snow pack.
> There was not enough regen braking action and the car would get up to 80
> mph
> going down a slick hill.
>
> Now, when coming down this hill, I have three heater units running, all
> the
> lights running, power steering, power brakes, fans and pump running which
> now slows the car down and generating all the power to drive these units,
> while the motor amperes and battery amps read ZERO !!!
>
> This is what I call mechanical REGEN.
>
> Remember, that you cannot made a DC current go both ways at the same exact
> time. You cannot charge a battery which is the flow of current from the
> negative plates to the positive plates while using power from the battery
> which is a flow from the positive plates to the negative plates. You can
> do
> only one or the other.
>
> If you have a alternator in a car, the alternator provides power to all
> the
> accessories, while the battery is being charge. If the alternator goes
> off
> line, than the battery provides the power.
>
> When you start up a ICE vehicle, the battery is only used to start the
> engine while the alternator is off line at the time. When the engine is
> running, then the alternator comes on and charges the battery and runs the
> accessories.
>
> Roland
>
>
> ----- Original Message -----
> From: "John Todd" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Friday, February 24, 2006 3:52 PM
> Subject: Can a generator be fitted on an EV, powered by the drivetrain?
>
>
> > Is it at all possible for a generator or alternator to run off the
> > motion
> > of
> > the vehicle itself? I am VERY new to Electric Vehicles, and I have
> > always
> > been curious about this.
> >
> > _________________________________________________________________
> > Don't just search. Find. Check out the new MSN Search!
> > http://search.msn.click-url.com/go/onm00200636ave/direct/01/
> >
> >
>
>
--- End Message ---
--- Begin Message ---
--- Danny Miller <[EMAIL PROTECTED]> wrote:
> As a side note, a device which converts replaceable
> chemical energy
> directly to electrical energy, whether solid,
> liquid, or gas is a fuel cell, not a battery.
...
> on the fly, and thus make a chemical fuel cell with
> a "fillup" tank and a tank of waste which
> can be electrically recharged back into fresh fuel
> again. I know of no promising possibilities
> standing out in this field though.
http://www.millenniumcell.com
these guys used to do vehicle size stuff(like the
Chrysler town and country demo), but have recently
changed their focus to military and consumer
electronics battery replacement.
It is basically a sodium borohydride slurry, which
releases H2 for use in a fuel cell. The problem I have
seen with this technology is the miserable round trip
efficiency of the offboard 'recharging' process
(turning sodium borate back into sodium borohydride).
that, and of course the infastracture questions...
~fortunat
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
John Todd wrote:
> Is it at all possible for a generator or alternator to run off the
> motion of the vehicle itself?
Yes; it's commonly done in electric vehicles and called "regenerative
braking". When you want to slow down, or keep your speed from increasing
when going downhill, the motor is used as a generator to charge the
batteries. Later, you can get most of this energy back to propel the
car.
But you can't generate power from the vehicle's motion on a continuous
basis. It's like driving with the brakes on.
--
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 ---
Thanks roger.
the precharge resistor I have is 80 ohm, 50 W
resistor. Since the power dissipated falls off
quickly, do you think this would suffice ?
what about the peak current the controller sees, would
the 80 ohm resistor defeat the purpose of precharging
? should i just use whatever curtis reccomends ?
as for fusing, i will look for a smaller fuse (that is
size more appropriately for the resistor.
thanks for the advice.
~fortunat
--- Roger Stockton <[EMAIL PROTECTED]> wrote:
> Fortunat Mueller [mailto:[EMAIL PROTECTED] wrote:
>
> > 1- is 80 ohms a reasonable value ?
>
> That depends on its power rating. Curtis recommends
> a 750R 10W resistor
> for the 1221C and a 620R 10W for the 1221B-6x. 80R
> will give you a
> *much* faster precharge at the expense of much
> higher peak current.
> With a 120V pack, the initial inrush current would
> be 1.5A, which
> results in 180W of dissipation in the resistor (if
> sustained). Of
> course, the current decays exponentially as the caps
> charge, so it falls
> off fast, but you still need a beefy enough resistor
> that it doesn't
> self-destruct immediately.
>
> > 2- is it ok for me to leave this precharge circuit
> > 'on' all the time when the key is on ? it will be
> in
> > parallel with the closed secondary contactor
> whenever
> > I am on the gas, and when I get off the gas, the
> > contactor will open and the precharge will 'hold'
> the
> > precharge in the controller.
> > I figure if something happens to the controller to
> > make it fail ON, i will lift off the gas, the
> > secondary contactor will open and then the
> precharge
> > fuse will blow quickly if asked to pass hundreds
> of
> > amps.
>
> Sounds reasonable. It think you definitely do want
> the precharge relay
> to remain closed whenever the key is on to keep the
> caps charged even
> when the secondary contactor opens. The 4.5A fuse
> may be a bit on the
> high side. It will certainly blow if the controller
> tries to draw any
> real current with your foot off the throttle,
> however, given that your
> peak precharge current is only 1.5A and even that
> could result in 180W
> dissipation in the precharge resistor if the
> controller caps fail to
> precharge, I'd prefer a lower rated fuse (something
> more like 0.5-1A).
> You may want to ensure the resistor is mounted where
> it cannot set
> anything on fire should the controller fail to
> precharge in a reasonable
> time, and realise that it is highly probable that in
> the event of a
> precharge failure the resistor may open before the
> fuse... will it break
> your pack voltage or not?
>
> Cheers,
>
> Roger.
>
>
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
Bill Dennis wrote:
>> Has anyone looked into the possibility of hooking a high-voltage
>> switch or contactor or breaker up to the brake pedal so that under
>> normal circumstances, when you were just applying the brake in
>> daily use, nothing would get disconnected -- but if you really
>> pressed hard or fast on the pedal, the switch would open?
A switch operated directly by hydraulic pressure? I'm sure it's
possible. Probably something like a big knife switch, with a spring to
force it open, and a little latch pin. The latch pin is pulled out by a
little hydraulic cylinder if the pressure in the brake line reaches "X".
I'm not sure this would be a useful feature, though. I can imagine
accidentally tromping on the brake pedal when there's no emergency, and
so tripping off this disconnect that is a pain to reset.
Nick Austin wrote:
> Are there any symptoms of a controller "fail full on" condition that
> can be easily detected?
(Presumably *before* the car drives through the garage wall :-)
Yes; basically, the controller has a current limit. If it is working, it
keeps the current below this. If it fails "on", the current will exceed
this value (within a fraction of a second)! So, you could have a second
electronic circuit breaker that detects the motor current, and drops the
contactors. Such a device could operate a lot faster than a fuse or
circuit breaker.
--
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 ---
Jeff Shanab wrote:
> I think the turbo idea can be made to do more work than it consumes if
> you use the heat to expand the nitrogen in the air around us to spin a
> pressure and volocity staged turbine, instead of just stuffing a fan
> into the stream of hot gasses.
GM built a car around 1960 with a free piston engine (an engine with no
output shaft), whose sole purpose was to generate hot exhaust gases.
These gases then spun a turbine which drove the back wheels. I don't
recall the name offhand, but it looked like the Batmobile!
--
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 ---
They would be if the motors were switched end engaged with clutches or some
other arrangement.
The control systems would need to be able to address each system in the car
to turn on or off a motor and move the electricity from one motor to another.
Lawrence Rhodes <[EMAIL PROTECTED]> wrote:
Extra motors are not redundent. All the fast EV's have two motors or more.
Lawrence Rhodes....
----- Original Message -----
From: "ziperle"
To:
Sent: Friday, February 24, 2006 5:06 PM
Subject: Newbie question: Multiple cheap motors to drive a vehicle
>I just read the EV article in Make magazine and it got me thinking
> real hard about doing an EV conversion. There is a picture of a
> Datsun with 3 motors installed that was converted by Tom True and Don
> Crabtree. What is the advantage of doing this? Is there any sense in
> doing cheap redundant motors and batteries RAIM?
>
> New term maybe - R.edundant A.rray of I. independent or inexpensive
> M.otors?
>
> Crazy thought but EVs offer the possibility of driving the vehicle
> with redundant systems. The thought I have is kind of like RAID or
> JBOD (just a bunch of harddrives) for a computer, and doing this to a
> car. If a single component were to fail, the vehicle might be able to
> continue moving on the balance of the systems that are still
> functioning. Obviously, failover mechanisms would have to be baked
> into the design.
>
> For example, a 2 wheeled vehicle with balanced batteries, motors and
> controllers. One half of the systems could fail and the car could
> continue to move although slower and for a shorter distance. If the
> car had 4 wheels and separate controllers and batteries, the car could
> theoretically take a 75% component failure and still move.
>
> Other possibilities are to failover some of the systems to extend the
> range. For example, a motor fails; the battery and controller could
> be engaged onto the still working motor.
>
> Another thought is with a quad system, options exist like performance
> mode - run all for systems at the same time. Economy mode could run
> on half of the systems (front or rear wheels).
>
> I found some DC treadmill motors cheap and in the 1-2.5hp range
> depending on input voltage? An example motor I found is rated
> [EMAIL PROTECTED] to [EMAIL PROTECTED] and 5 amps, weighs 14lbs with a large
> fly-wheel that would probably be removed.
>
> I know this sounds wimpy compared to the Advanced DC or ETek motors
> but does this make any sense for an entry level conversion? I know
> there are many other design considerations (donor car, batteries,
> controller, etc.) but the motor seems like a good place to start a
> design.
>
> Also, does anyone have experience with controllers? Is it easier to
> control higher voltage or amperage? I would think that higher voltage
> has the advantage of permitting smaller gauge wire and maybe better
> efficiency when it comes to voltage drops from impedance and
> resistance that are inherent in batteries, motors and controller
> components.
>
> Thanks for the advice and opinions.
>
>
>
>
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
k.i.s.s.
Why not just motinor the throttle possition. If the throttle pedle is all
the way up thus having the "throttle up" microswitch closed and then looking
to see if there is any "GO" current something must be wrong!!! EMERGENCY
OPEN THE GIANT CONTACTOR!!!!
What is so complicated? Obviously I must be missing something!
Mark Grasser
Subject: Re: Trip in Emergency Only
Bill Dennis wrote:
Has anyone looked into the possibility of hooking a high-voltage
switch or contactor or breaker up to the brake pedal so that under
normal circumstances, when you were just applying the brake in
daily use, nothing would get disconnected -- but if you really
pressed hard or fast on the pedal, the switch would open?
A switch operated directly by hydraulic pressure? I'm sure it's
possible. Probably something like a big knife switch, with a spring to
force it open, and a little latch pin. The latch pin is pulled out by a
little hydraulic cylinder if the pressure in the brake line reaches "X".
I'm not sure this would be a useful feature, though. I can imagine
accidentally tromping on the brake pedal when there's no emergency, and
so tripping off this disconnect that is a pain to reset.
Nick Austin wrote:
Are there any symptoms of a controller "fail full on" condition that
can be easily detected?
(Presumably *before* the car drives through the garage wall :-)
Yes; basically, the controller has a current limit. If it is working, it
keeps the current below this. If it fails "on", the current will exceed
this value (within a fraction of a second)! So, you could have a second
electronic circuit breaker that detects the motor current, and drops the
contactors. Such a device could operate a lot faster than a fuse or
circuit breaker.
--
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 ---
** Reply to message from "Mark Grasser" <[EMAIL PROTECTED]> on Sat, 25
Feb 2006 11:06:43 -0500
> Why not just motinor the throttle possition. If the throttle pedle is all
> the way up thus having the "throttle up" microswitch closed and then looking
> to see if there is any "GO" current something must be wrong!!! EMERGENCY
> OPEN THE GIANT CONTACTOR!!!!
This sounds real good to me.
Dale Curren
--- End Message ---
--- Begin Message ---
Hi Don,
Thanks for the input. I'm looking to do a budget conversion. Probably not
too scientific or engineered but I should be able to cost out the motors
somewhere around $10-20 per HP.
Sounds, like I should scrap the redundant idea and keep it simple.
If I ganged the motors together like the "performance" conversions do with
"performance" motors, can I treat the motors like one load on the controller?
Based on the voltage of the motors I'm probably going to be stuck with parallel
connections rather than series.
I've read about conversions with 8HP motors that peak to say 12HP and are
ready for the street. Am I safe to sum the HP's of the motors toegether to get
to into the 8-10HP range for a street capable conversion?
I'd then move back to the controller and batteries. Im thinking of doing a
small pickup truck for flexibility on some of my design choices but I'm not
committed to any specific vehicle type. Theres so much to research to bring
this together.
Thanks,
Paul
Don Cameron <[EMAIL PROTECTED]> wrote:
I am sure there are a number of things to consider:
- a controller that can handle multiple motors
- a controller that can accommodate differential
- the added extra unsprung weight of the motors mounted at the wheels (leads
to poor performance)
Also consider: how often to motors fail? Enough to warrant building a
redundant system? When a motor fails is it a safety issue, that may require
a redundant system? Brakes - yes. Motors - ?
For a project such as an EV conversion, it is important to understand your
goals. Is it new technology such as failover mechanisms or an inexpensive
EV conversion? Once you get clear on your goal and constraints, it will
help to make these decisions much easier.
Don
Victoria, BC, Canada
See the New Beetle EV Conversion Web Site at
www.cameronsoftware.com/ev/
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of ziperle
Sent: February 24, 2006 5:06 PM
To: [email protected]
Subject: Newbie question: Multiple cheap motors to drive a vehicle
I just read the EV article in Make magazine and it got me thinking real hard
about doing an EV conversion. There is a picture of a Datsun with 3 motors
installed that was converted by Tom True and Don Crabtree. What is the
advantage of doing this? Is there any sense in doing cheap redundant motors
and batteries RAIM?
New term maybe - R.edundant A.rray of I. independent or inexpensive M.otors?
Crazy thought but EVs offer the possibility of driving the vehicle with
redundant systems. The thought I have is kind of like RAID or JBOD (just a
bunch of harddrives) for a computer, and doing this to a car. If a single
component were to fail, the vehicle might be able to continue moving on the
balance of the systems that are still functioning. Obviously, failover
mechanisms would have to be baked into the design.
For example, a 2 wheeled vehicle with balanced batteries, motors and
controllers. One half of the systems could fail and the car could continue
to move although slower and for a shorter distance. If the car had 4 wheels
and separate controllers and batteries, the car could theoretically take a
75% component failure and still move.
Other possibilities are to failover some of the systems to extend the range.
For example, a motor fails; the battery and controller could be engaged onto
the still working motor.
Another thought is with a quad system, options exist like performance mode -
run all for systems at the same time. Economy mode could run on half of the
systems (front or rear wheels).
I found some DC treadmill motors cheap and in the 1-2.5hp range depending on
input voltage? An example motor I found is rated [EMAIL PROTECTED] to
[EMAIL PROTECTED] and 5 amps, weighs 14lbs with a large fly-wheel that would
probably be removed.
I know this sounds wimpy compared to the Advanced DC or ETek motors but does
this make any sense for an entry level conversion? I know there are many
other design considerations (donor car, batteries, controller, etc.) but the
motor seems like a good place to start a design.
Also, does anyone have experience with controllers? Is it easier to control
higher voltage or amperage? I would think that higher voltage has the
advantage of permitting smaller gauge wire and maybe better efficiency when
it comes to voltage drops from impedance and resistance that are inherent in
batteries, motors and controller components.
Thanks for the advice and opinions.
---------------------------------
Relax. Yahoo! Mail virus scanning helps detect nasty viruses!
--- End Message ---
--- Begin Message ---
Well it took me long enough, but I have finally gotten around to making
the SAFT STM series user's manual and the Power-Sonic Technical manual
available agin at my website. Both have excellent technical
information.
http://www.davesevs.com/evtechpapers.htm
David Brandt
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
Looks nice!
As someone who used to get paid to build electric buses, it was deja vu.
For safety's sake I thought I would mention two things. In this shot
http://www.solarvan.co.uk/ac04.jpg there is a fender washer that looks
light it might give a path for an unintentional short in your pack.
I like the battery pack layout, but it looks like there is basically
zero crush room before you battery pack gets punctured in the event of
you getting rear-ended. I am sure others have mentioned this.
Also, how is the fore-aft battery string spacing maintained under
braking?
I am glad you are having luck with Zapi. I haven't had a great
experience with them here. I am using much smaller AC drives from them
and the documentation and support has been sub-par, so far. I am
actually using small Curtis AND Zapi drives, CANbus controlled, and a
3rd party gearmotor. It is for a robot, actually Support for AC
products in the US seems to be ok, but not great. The proprietary
CANbus documentation seems to be the problem. That and the fact that
Zapi shipped the wrong controllers- twice. Hopefully in the end it will
all work out.
FWIW, I think Curtis or Zapi would sell me a controller if I bought a
motor they had worked with before e.g. CFR in Italy, or another German
brand. But as I am an OEM and used to integrate AC drives in vehicles,
that might have changed their mind.
How do you like the guibo/ rubber coupling for the driveshaft. I had
one on my BMW 2002 and had to replace a few, but I was young driver.
Good luck!
Seth
On Feb 25, 2006, at 2:41 AM, Electric Vehicle Discussion List wrote:
Date: Sat, 25 Feb 2006 05:59:21 -0000
From: "Peter Perkins" <[EMAIL PROTECTED]>
Subject: Low voltage (96v) AC Conversion update 250206
To: <[email protected]>
Message-id: <[EMAIL PROTECTED]>
MIME-version: 1.0
Content-type: text/plain; charset=iso-8859-1
Content-transfer-encoding: 8BIT
Dear List Members.
It works!
The wheels go round! And the right way. Well they do now, after I
swaped the
motor connections, and corrected one wiring mistake on the throttle
pot!
Initial one mile road test thoughts,
1) Much improved acceleration and start ability.
2) Regeneration! Great, not had that before :)
3) Quieter at crusing speed. Only road/tyre/wind noise now.
Cedric Lynch Li-Ion cell protectors all ok.
Modified Zivan 3kw 25A IUa NG3 onboard charger functioning ok
Home made 6kw 55A offboard charger functioning ok.
Battery heater ok, temp 20C.
Vehicle is now on charge, receiving a CV balancing charge for a few
hours,
probably overnight, TS 200ah cells have been stood for 4-5 months.
Inter
cell voltage variation <75mv.
28 cells, pack voltage is steady at 117v and current is slowly
falling. Less
than 4A now.
A bit more fiddling to do (A project like this is never finished
really!),
and some adjustments to AC controller parameters to make.
I'll pass on performance tests asap.
PS
I have a Zapi programming console now, if anyone in the UK ever needs
to
borrow one.
Peter
www.solarvan.co.uk
See below for old update and pics/specs
Dear Members
Some of you will know I am doing a low cost, low voltage DC to AC
upgrade at
present. (New information and progress report is at the bottom of this
mail)
I will soon be running a 96v 450A Zapi 3phase ac controller with regen
and a
96v 3phase 12kw con rated induction motor.
The motor and controller cost me £2000 brand new.
I am lucky enough to own a pack of 200Ah TS cells and can report good
life
and performance in the 2+ years I have had them.
A few links for interest are here.
http://www.electrofit-zapi.com/hfacinverters.htm
www.solarvan.co.uk
The motor came from Best Motors in Italy.
http://www.bestmotor.it/frameset_ei.html
They do not list AC motors on the site, but do supply them to order and
spec.
Zapi only supply a controller with a motor, as they require matching.
That's
why I ended up with an Italian motor as well.
Curtis operate the same policy I think. You will be lucky if they sell
you a
controller without a motor.
I went for the Zapi controller as it allowed a higher voltage 96v
instead of
the curtis 80v.
A couple of pics of the motor/controller versus my old 120v 400A curtis
stuff are here, as are motor spec drawing, motor torque voltage curves
and
Zapi AC controller manual.
www.solarvan.co.uk/ac017.jpg
www.solarvan.co.uk/ac021.jpg
www.solarvan.co.uk/bestmotor.pdf
www.solarvan.co.uk/ac3manual.pdf
www.solarvan.co.uk/MVC-001F.jpg
www.solarvan.co.uk/MVC-002F.jpg
www.solarvan.co.uk/MVC-003F.jpg
www.solarvan.co.uk/MVC-004F.jpg
www.solarvan.co.uk/MVC-005F.jpg
Hope to get upgrade finished by 010406
New for 04/02/06 are ten more pictures of my current progress.
They are at www.solarvan.co.uk/ac01.jpg to www.solarvan.co.uk/ac10.jpg
inclusive. Just change the number to get the other pictures. They are
about
350kb each to give full detail.
My TS Cells are now contained in a false floor battery and insulation
layer
cake inside the vehicle. They are securely strapped down with that 12mm
300kg breaking strain nylon packing tape, tensioned and crimped, two
straps
per cell to about 100kg each. I have a full set of crimping, tensioning
tools, crimps and miles of tape if anyone wants to borrow it in UK. It
was
excellent for securing and compressing cells. Fits perefectly into
slots in
TS cells.
Basically the floor is raised about 6 inches now.
It's layered as follows.
1st layer, onto original van metal floor, 25mm Kingspan silvered
insulation.
2nd layer, 9mm plywood sheet drilled and bolted through insulation and
metal
vehicle floor, drilled and fitted with 12mm strapping before placing in
vehicle.
3rd layer, 28x200ah TS Cells laid out as you see, and securely strapped
down, with white electric blanket heating wire underneath all cells to
keep
them warm.
Note, sides also filled with blocks of Kingspan insulation to make a
sealed
compartment.
4th layer, sheet of 2mm ultra lightweight compressible foam to seal
gaps
between edges and top sheet of thermo insulation, and to provide
electrical
insulation between silvered side of thermo insulation and cells. Well
you
never know, a loose wire can occur!
5th layer, another sheet of 25mm Kingspan silvered insulation.
6th layer, a sheet of 12mm plywood to provide load flooring, bolted
through
layers to vehicle metal body.
7th layer, Carpet! Not yet fitted as you see.
I was happy to sacrifice some load space to allow the secure and
insulated
fitting of the most expensive item, the battery pack!
The under cell mains powered heating is thermostat controlled, and
shuts off
when cells reach 25C.
I have left provision for forced air ventilation through cells if
required,
but I will monitor pack temp and see if I actually need to fit this!
The ambient temp is quite low here in Northern England, I don't
envisage
overheating will be a major problem.
The underseat electronics compartment is coming along well. It's still
wires
all over the place at the moment, but I'm pretty pleased with progress.
The AC motor is now in situ underneath the vehicle on a very secure
mild
steel mounting as you can see.
My ETA of 01/04/06 looks quite acheivable at present.
I will update my website when it's finally done.
Regards
Peter Perkins.
Chilly in the UK!
--- End Message ---
