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Discussion Starter #1
Hi Folk's,

I was thinking (it can happen) about taking my 10kwh worth of Thundersky batts ($5k 32ea 100ah) out of the E-Cat www.evalbum.com/2749 , selling my E-Porsche www.evalbum.com/1273 ,$7k and putting the 200lb battery pack LiFePO4 3.3V x 32 = 106V (wire in series instead of buddy pairs) into a 1700 lb Karman Ghia (maybe Honda Del-Sol if same weight), finish weight 1900lb. I have an E-Tek RT 72V PM motor, curious how that would do in an EV, maybe to small. But that would be a peppy lightweight conversion. Not sure if the LiFePO4 batteries will go less than 80% dod and the max current 200A have to check with Thundersky (or Dave Kois from evcomponents where I bought but I think they fizzled.) I figure at 330whr per mile (measured on the AC side) on my 2800lb Porsche 914 should be 1900/2800 x 330 = 224 whr per mile in a lighter Ghia-etc. So at 80% dod 80ah x 3.3V x 32 = 8448 whr / 224 = 37 miles range, maybe that's wishful thinking on a 200lb lightweight pack, I dunno but looks g!
ood on paper :)

I finished putting in all the fusible links between the batteries, 4 sizes smaller (#12) than the main (#8) with hypalon fireproof insulation but normal copper wire inside (in E-Cat), 150A main breaker. I noticed that the wire lengths have to be "tuned" to the same length between the buddy pairs, the previous 60A buddy pair fuses were darkenned (probably getting ready to pop) on the shorter wires of non tuned buddy pairs. So this time I was careful to make the buddy pair wires the same length even if one terminal was closer to the next battery than the other. This current upgrade was for converting a Johnson 9.9hp 1gph sailmaster to electric with the Etek-RT motor but now I'm thinking of maybe going over to the "dark side" and just using it as gas since I'm hitting that little laws of physics thingy: hull speed mph = 1.5 x sqr-root of hull length (18') or 6.4mph so above 4hp it ramps up exponentially, need a 25hp to go twice as fast (my kid wants to go faster, kneeboard/s!
ki). Then I would free up the lithium stuff for a lightweight conversion, no more overweight lead sleds with 16-20 Trojans for me with poor braking/handling.

Have a renewable energy day,
mark
www.reevadiy.org community service RE & EV's
The 3 leg stool is solar,wind & EV's
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Discussion Starter #2
Mark

One comment about the motor. Often people will try and put the
smallest motor in trying to save money. In your case, you are using
one you already have. But I think it's false economy to use a small
motor.

First, you are running the motor closer to it's limits and closer to
blowing it up. You have to do more for cooling, it will be critical.
You will also wear out brushes faster, not to mention shorter bearing
life. 5 years instead of 10, maybe not that big a deal. But I still
don't like planning on running a motor on or near it's limit.

Second, it's not necessarily going to be more efficient. In fact it
might be less efficient than a larger motor. A larger motor won't have
to work as hard, less heat, less wear and tear. This isn't like a
gasser. If you swap out a 4 cylinder for a big block V8, you'll have
plenty of power. But you'll never get anywhere near the fuel economy.
Ever. But a 9" motor can be just as efficient as a 6.7".

Third, a larger motor will do more if you need it. If you drive on
city streets all the time, you'll never need the extra power. But if
you have to drive on the highway, if you live in a hilly area, if you
want to drive with 4 passengers in a 4 passenger car, if you want to
have some fun (PODC) once in a while ....

And a larger motor isn't that much more weight relative to the car.
What's an 6.7" ADC, 75 lbs? A 9" ADC is 150. So you have a 75lb
penalty, less than 4% of the car. I think it's worth it.

Just my opinion. Worth everything you paid.

DAC

PS I'm jealous, you have much better toys than I do.


On Tue, Oct 19, 2010 at 8:44 AM, Mark Hanson <[email protected]> wro=
te:
>
> Hi Folk's,
>
> I was thinking (it can happen) about taking my 10kwh worth of Thundersky =
batts ($5k 32ea 100ah) out of the E-Cat www.evalbum.com/2749 , selling my E=
-Porsche www.evalbum.com/1273 ,$7k and putting the 200lb battery pack LiFeP=
O4 3.3V x 32 =3D 106V (wire in series instead of buddy pairs) into a 1700 l=
b Karman Ghia (maybe Honda Del-Sol if same weight), finish weight 1900lb. =
I have an E-Tek RT 72V PM motor, curious how that would do in an EV, may=
be to small. But that would be a peppy lightweight conversion. Not su=
re if the LiFePO4 batteries will go less than 80% dod and the max current 2=
00A have to check with Thundersky (or Dave Kois from evcomponents where I b=
ought but I think they fizzled.) I figure at 330whr per mile (measured o=
n the AC side) on my 2800lb Porsche 914 should be 1900/2800 x 330 =3D 224 w=
hr per mile in a lighter Ghia-etc. So at 80% dod 80ah x 3.3V x 32 =3D 8448 =
whr / 224 =3D 37 miles range, maybe that's wishful thinking on a 200lb ligh=
tweight pack, I dunno but looks g!
> ood on paper :)
>
> I finished putting in all the fusible links between the batteries, 4 size=
s smaller (#12) than the main (#8) with hypalon fireproof insulation but no=
rmal copper wire inside (in E-Cat), 150A main breaker. I noticed that th=
e wire lengths have to be "tuned" to the same length between the buddy pair=
s, the previous 60A buddy pair fuses were darkenned (probably getting ready=
to pop) on the shorter wires of non tuned buddy pairs. So this time I w=
as careful to make the buddy pair wires the same length even if one termina=
l was closer to the next battery than the other. This current upgrade wa=
s for converting a Johnson 9.9hp 1gph sailmaster to electric with the Etek-=
RT motor but now I'm thinking of maybe going over to the "dark side" and ju=
st using it as gas since I'm hitting that little laws of physics thingy: hu=
ll speed mph =3D 1.5 x sqr-root of hull length (18') or 6.4mph so above 4hp=
it ramps up exponentially, need a 25hp to go twice as fast (my kid wants t=
o go faster, kneeboard/s!
> ki). Then I would free up the lithium stuff for a lightweight conve=
rsion, no more overweight lead sleds with 16-20 Trojans for me with poor br=
aking/handling.
>
> Have a renewable energy day,
> mark
> www.reevadiy.org community service RE & EV's
> The 3 leg stool is solar,wind & EV's
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>



-- =

http://www.evalbum.com/2149

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Discussion Starter #3
I think your idea of using a Ghia is great. I'm kinda biased here but my Ghia
with 16 flooded LA batteries and only 96 volts would giddy up to 85 mph
given a bit of time. Jumped up to 65 no problem. No speed demon but nice.
Now if you could give it 120 or so volts and a controller able to output 600
or more amps then I think you will be doing very well. The Ghia can hold
quite a few batteries. You may loose the back seat area but since you drive
a 914 who cares, right? They are light weight and agile and given that
LIFEPO batteries are considerably lighter it would be much more fun to
drive. No more lead sled. :)

You might be hard pressed to get $7k for your 914 in this economy. Hope the
best for that.

Pete :)

http://greenev.zapto.org/electricvw
http://greenev.zapto.org/63ev

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If you don't understand, be patient, you will. Now I understand. :)
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Discussion Starter #4
gottdi wrote:

>
> I think your idea of using a Ghia is great. I'm kinda biased here
> but my Ghia
> with 16 flooded LA batteries and only 96 volts would giddy up to 85
> mph
> given a bit of time. Jumped up to 65 no problem. No speed demon but
> nice.
> Now if you could give it 120 or so volts and a controller able to
> output 600
> or more amps then I think you will be doing very well. The Ghia can
> hold
> quite a few batteries. You may loose the back seat area but since
> you drive
> a 914 who cares, right? They are light weight and agile and given that
> LIFEPO batteries are considerably lighter it would be much more fun to
> drive. No more lead sled. :)
>
> You might be hard pressed to get $7k for your 914 in this economy.
> Hope the
> best for that.


I think the most challenging part will be to find a Ghia that does not
require tons of body work, and is not way expensive.




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Discussion Starter #5
Mark Hanson wrote:
> thinking about...
> selling my E-Porsche www.evalbum.com/1273, $7k

I agree that you may have a hard time selling it in this market. Several
very nice EVs have recently been offered at good prices, and didn't sell.

I think the pre-announcement of the Volt and Leaf have "poisoned the
well" for other EV sellers for the time being. Once these cars are out
and people can see what they really cost, how they actually work, and
where they will be sold, then other EVs may again have a chance.

> taking my 10kwh 200 lb worth of Thundersky batts... into a 1700 lb Karman Ghia (maybe
> Honda Del-Sol if same weight), finish weight 1900lb.

The Ghia is pretty light; not sure about the Honda. It's going to have
to be a very light car with only 200 lbs of batteries. These are not
high current batteries.

> I have an E-Tek RT 72V PM motor, curious how that would do in an EV

It's too small for anything except a very light vehicle. This is a very
efficient motor, but has very poor high current capability. You can't
run it at 5x rated current for 1 minute to get fast acceleration like
you can a big ol' series motor.

With this motor and pack, I'd look for a *very* lightweight vehicle. How
about an old CitiCar? Keep the frame and title (the title says it's a
normal car, not an NEV :) ). With 200# instead of 500# of batteries,
it's going to fly! Replace the brakes and suspension with modern parts
to improve handling.

Or look for other micro-cars. An Isetta, Gogomobile, Honda AN-600, or
Crosley (a Hotshot perhaps)?

> I finished putting in all the fusible links between the batteries...
> I noticed that the wire lengths have to be "tuned" to the
> same length between the buddy pairs...

Makes sense.

--
Lee A. Hart | Ring the bells that still can ring
814 8th Ave N | Forget the perfect offering
Sartell MN 56377 | There is a crack in everything
leeahart earthlink.net | That's how the light gets in -- Leonard Cohen

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Discussion Starter #6
On 19 Oct 2010 at 8:44, Mark Hanson wrote:

> I figure at 330whr per mile (measured on the AC side) on my 2800lb
> Porsche 914 should be 1900/2800 x 330 = 224 whr per mile in a lighter
> Ghia-etc.

I don't think energy usage scales this way with weight. True, you're
accelerating less mass, but acceleration is only part of what drains the
battery. And while weight affects rolling resistance, there are other
components of rolling resistance that I don't think it does (I could be
wrong). Weight has no effect at all on aero drag, AFAIK.

So while a lighter vehicle will certainly use less energy, I don't think the
improvement will be as dramatic as you hope.

That said, Ghias have a rep for being real WH sippers in the EV world. (But
then so do Porsche 914s.)

It seems to me that you've been looking for the "holy grail" in economical,
efficient EV commuting for many years. You might want to take a look at
some old Solectria Forces for ideas. James Worden was just about fanatical
about minimizing energy usage. He used a low friction, lightweight aluminum
transaxle and a high efficiency AC induction drive with lots of regen, and
kept the converted weight in the early cars to 2100lb (later cars were
closer to 2500lbs, IIRC). Forces would use ~150-160 Wh/mi (at the battery)
at a steady 45mph.

David Roden - Akron, Ohio, USA
EVDL Administrator

= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
EVDL Information: http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Note: mail sent to "evpost" and "etpost" addresses will not
reach me. To send a private message, please obtain my
email address from the webpage http://www.evdl.org/help/ .
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =


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Discussion Starter #7
Rolling resistance is directly proportional to weight -- double the weight
double the drag. The nonlinear terms are very small and safely neglected. This
translates directly for low speeds, so for a city speeds a lighter car is
definitely better, and the Whr/mi will directly scale. At highway speeds about
1/2 your drag is air resistance, in that case weight is less of an effect.


For Mark at low speeds it will drop from 330 whr / mi to 224 whr / mi, but at
highway speeds the drop might be just something like 330 to 280 Whr/mi (or
better or worse depending on speed). Of course this assume tires with the same
rolling resistance, equally well aligned suspensions, etc.



________________________________
From: EVDL Administrator <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Tue, October 19, 2010 11:12:54 AM
Subject: Re: [EVDL] Lightweight Most Efficient Conversion

On 19 Oct 2010 at 8:44, Mark Hanson wrote:

> I figure at 330whr per mile (measured on the AC side) on my 2800lb
> Porsche 914 should be 1900/2800 x 330 = 224 whr per mile in a lighter
> Ghia-etc.

I don't think energy usage scales this way with weight. True, you're
accelerating less mass, but acceleration is only part of what drains the
battery. And while weight affects rolling resistance, there are other
components of rolling resistance that I don't think it does (I could be
wrong). Weight has no effect at all on aero drag, AFAIK.

So while a lighter vehicle will certainly use less energy, I don't think the
improvement will be as dramatic as you hope.

That said, Ghias have a rep for being real WH sippers in the EV world. (But
then so do Porsche 914s.)

It seems to me that you've been looking for the "holy grail" in economical,
efficient EV commuting for many years. You might want to take a look at
some old Solectria Forces for ideas. James Worden was just about fanatical
about minimizing energy usage. He used a low friction, lightweight aluminum
transaxle and a high efficiency AC induction drive with lots of regen, and
kept the converted weight in the early cars to 2100lb (later cars were
closer to 2500lbs, IIRC). Forces would use ~150-160 Wh/mi (at the battery)
at a steady 45mph.

David Roden - Akron, Ohio, USA
EVDL Administrator

= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
EVDL Information: http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Note: mail sent to "evpost" and "etpost" addresses will not
reach me. To send a private message, please obtain my
email address from the webpage http://www.evdl.org/help/ .
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =


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Discussion Starter #8
Eh, not entirely.

The *tire* drag may be somewhat related to weight
but (especially at higher speeds) the aero drag
is completely unrelated except where weight
translates into a bigger car (more frontal area)
or worse Cd or the ride height changes and this
affects aero drag, but other than those secondary
effect, higher weight will have only two immediate effects:
- increase tire rolling resistance (larger deflection)
- increase kinetic energy (more mass to accelerate)
so acceleration will be slower and/or consume more
energy to achieve the same speed.
With regen braking you can roughly re-capture half
the kinetic energy back into the battery pack, to
be re-used for your next acceleration....
In case no re-gen is present, all kinetic energy will
be lost at your next stop, so this also turns a higher
weight into higher losses.

Hope this clarifies,

Cor van de Water
Director HW & Systems Architecture Group
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [email protected]
Tel: +1 408 383 7626 VoIP: +31 20 3987567 FWD# 25925
Tel: +91 (040)23117400 x203 XoIP: +31877841130

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of David Dymaxion
Sent: Tuesday, October 19, 2010 11:26 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Lightweight Most Efficient Conversion

Rolling resistance is directly proportional to weight -- double the
weight double the drag. The nonlinear terms are very small and safely
neglected. This translates directly for low speeds, so for a city speeds
a lighter car is definitely better, and the Whr/mi will directly scale.
At highway speeds about
1/2 your drag is air resistance, in that case weight is less of an
effect.


For Mark at low speeds it will drop from 330 whr / mi to 224 whr / mi,
but at highway speeds the drop might be just something like 330 to 280
Whr/mi (or better or worse depending on speed). Of course this assume
tires with the same rolling resistance, equally well aligned
suspensions, etc.



________________________________
From: EVDL Administrator <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Tue, October 19, 2010 11:12:54 AM
Subject: Re: [EVDL] Lightweight Most Efficient Conversion

On 19 Oct 2010 at 8:44, Mark Hanson wrote:

> I figure at 330whr per mile (measured on the AC side) on my 2800lb
> Porsche 914 should be 1900/2800 x 330 = 224 whr per mile in a lighter
> Ghia-etc.

I don't think energy usage scales this way with weight. True, you're
accelerating less mass, but acceleration is only part of what drains the
battery. And while weight affects rolling resistance, there are other
components of rolling resistance that I don't think it does (I could be
wrong). Weight has no effect at all on aero drag, AFAIK.

So while a lighter vehicle will certainly use less energy, I don't think
the improvement will be as dramatic as you hope.

That said, Ghias have a rep for being real WH sippers in the EV world.
(But then so do Porsche 914s.)

It seems to me that you've been looking for the "holy grail" in
economical, efficient EV commuting for many years. You might want to
take a look at some old Solectria Forces for ideas. James Worden was
just about fanatical about minimizing energy usage. He used a low
friction, lightweight aluminum transaxle and a high efficiency AC
induction drive with lots of regen, and kept the converted weight in the
early cars to 2100lb (later cars were closer to 2500lbs, IIRC). Forces
would use ~150-160 Wh/mi (at the battery) at a steady 45mph.

David Roden - Akron, Ohio, USA
EVDL Administrator

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL
Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = =
= = = = = = = = = = = =
Note: mail sent to "evpost" and "etpost" addresses will not reach me.
To send a private message, please obtain my email address from the
webpage http://www.evdl.org/help/ .
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =


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Discussion Starter #9
Oops,
Should not be answering email after midnight.
I missed where you specifically said Rolling resistance.
Note however that it may have a non-linear relation...
(So, twice the weight is not exactly twice the drag...)

Regards,

Cor van de Water
Director HW & Systems Architecture Group
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [email protected]
Tel: +1 408 383 7626 VoIP: +31 20 3987567 FWD# 25925
Tel: +91 (040)23117400 x203 XoIP: +31877841130

-----Original Message-----
From: Cor van de Water
Sent: Wednesday, October 20, 2010 12:10 AM
To: 'Electric Vehicle Discussion List'
Subject: RE: [EVDL] Lightweight Most Efficient Conversion

Eh, not entirely.

The *tire* drag may be somewhat related to weight but (especially at
higher speeds) the aero drag is completely unrelated except where weight
translates into a bigger car (more frontal area) or worse Cd or the ride
height changes and this affects aero drag, but other than those
secondary effect, higher weight will have only two immediate effects:
- increase tire rolling resistance (larger deflection)
- increase kinetic energy (more mass to accelerate)
so acceleration will be slower and/or consume more
energy to achieve the same speed.
With regen braking you can roughly re-capture half the kinetic energy
back into the battery pack, to be re-used for your next acceleration....
In case no re-gen is present, all kinetic energy will be lost at your
next stop, so this also turns a higher weight into higher losses.

Hope this clarifies,

Cor van de Water
Director HW & Systems Architecture Group Proxim Wireless Corporation
http://www.proxim.com
Email: [email protected] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [email protected]
Tel: +1 408 383 7626 VoIP: +31 20 3987567 FWD# 25925
Tel: +91 (040)23117400 x203 XoIP: +31877841130

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of David Dymaxion
Sent: Tuesday, October 19, 2010 11:26 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Lightweight Most Efficient Conversion

Rolling resistance is directly proportional to weight -- double the
weight double the drag. The nonlinear terms are very small and safely
neglected. This translates directly for low speeds, so for a city speeds
a lighter car is definitely better, and the Whr/mi will directly scale.
At highway speeds about
1/2 your drag is air resistance, in that case weight is less of an
effect.


For Mark at low speeds it will drop from 330 whr / mi to 224 whr / mi,
but at highway speeds the drop might be just something like 330 to 280
Whr/mi (or better or worse depending on speed). Of course this assume
tires with the same rolling resistance, equally well aligned
suspensions, etc.



________________________________
From: EVDL Administrator <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Tue, October 19, 2010 11:12:54 AM
Subject: Re: [EVDL] Lightweight Most Efficient Conversion

On 19 Oct 2010 at 8:44, Mark Hanson wrote:

> I figure at 330whr per mile (measured on the AC side) on my 2800lb
> Porsche 914 should be 1900/2800 x 330 = 224 whr per mile in a lighter
> Ghia-etc.

I don't think energy usage scales this way with weight. True, you're
accelerating less mass, but acceleration is only part of what drains the
battery. And while weight affects rolling resistance, there are other
components of rolling resistance that I don't think it does (I could be
wrong). Weight has no effect at all on aero drag, AFAIK.

So while a lighter vehicle will certainly use less energy, I don't think
the improvement will be as dramatic as you hope.

That said, Ghias have a rep for being real WH sippers in the EV world.
(But then so do Porsche 914s.)

It seems to me that you've been looking for the "holy grail" in
economical, efficient EV commuting for many years. You might want to
take a look at some old Solectria Forces for ideas. James Worden was
just about fanatical about minimizing energy usage. He used a low
friction, lightweight aluminum transaxle and a high efficiency AC
induction drive with lots of regen, and kept the converted weight in the
early cars to 2100lb (later cars were closer to 2500lbs, IIRC). Forces
would use ~150-160 Wh/mi (at the battery) at a steady 45mph.

David Roden - Akron, Ohio, USA
EVDL Administrator

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Discussion Starter #10
Hi Lee, Mark and All,

It's the low cost of gas plus the bad
economy that has dropped EV prices, sales for conversions.
Hang on to them until late next yr when gas prices hit
$4.50-5/gal then they will just like last time gas prices
rose, start selling well for much better prices.

On Mark's idea, the Ghia is an
excellent glider as John Bryan's got 100wthrs/mile on his
after some serious drag reduction. As the lithium's weigh
less it should help that. It's fairly aero and low frontal
area. Add low drag tranny fluid like Redline, LRR tires,
etc and should work well.

On the Etek I wouldn't do that as they
don't handle high power well or starting torque
requirements. On my E Woody at 1000 lbs I replaced my GE
Citi-car motor with an Etek and the etek burned out trying
to start up a slight hill/driveway. I put the GE back in and
no problem even though it was 3.5hp vs the etek's 9hp
rating.

For Mark in more hilly areas I'd go with
a D+D Sep-Ex motor, controller in their largest size,
12-16hp depending on batt voltage. Their prices are very
reasonable and having a sale at the moment on 6.7" motors,
controllers they sell, same motor in series as the
Killacycle uses.

Jerry Dycus.

----- Original Message Follows -----
From: Lee Hart <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Subject: Re: [EVDL] Lightweight Most Efficient Conversion
Date: Tue, 19 Oct 2010 11:53:48 -0500

>Mark Hanson wrote:
>> thinking about...
>> selling my E-Porsche www.evalbum.com/1273, $7k
>
>I agree that you may have a hard time selling it in this
>market. Several very nice EVs have recently been offered
>at good prices, and didn't sell.
>
>I think the pre-announcement of the Volt and Leaf have
>"poisoned the well" for other EV sellers for the time
>being. Once these cars are out and people can see what
>they really cost, how they actually work, and where they
>will be sold, then other EVs may again have a chance.
>
>> taking my 10kwh 200 lb worth of Thundersky batts... into
>> a 1700 lb Karman Ghia (maybe Honda Del-Sol if same
>weight), finish weight 1900lb.
>
>The Ghia is pretty light; not sure about the Honda. It's
>going to have to be a very light car with only 200 lbs of
>batteries. These are not high current batteries.
>
>> I have an E-Tek RT 72V PM motor, curious how that would
>do in an EV
>
>It's too small for anything except a very light vehicle.
>This is a very efficient motor, but has very poor high
>current capability. You can't run it at 5x rated current
>for 1 minute to get fast acceleration like you can a big
>ol' series motor.
>
>With this motor and pack, I'd look for a *very* lightweight
>vehicle. How about an old CitiCar? Keep the frame and
>title (the title says it's a normal car, not an NEV :) ).
>With 200# instead of 500# of batteries, it's going to fly!
>Replace the brakes and suspension with modern parts to
>improve handling.
>
>Or look for other micro-cars. An Isetta, Gogomobile, Honda
>AN-600, or Crosley (a Hotshot perhaps)?
>
>> I finished putting in all the fusible links between the
>> batteries... I noticed that the wire lengths have to be
>> "tuned" to the same length between the buddy pairs...
>
>Makes sense.
>
>--
>Lee A. Hart | Ring the bells that still can ring
>814 8th Ave N | Forget the perfect offering
>Sartell MN 56377 | There is a crack in everything
>leeahart earthlink.net | That's how the light gets in --
>Leonard Cohen
>
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Discussion Starter #11
Hi folks,

> On 19 Oct 2010 at 8:44, Mark Hanson wrote:
>
>> I figure at 330whr per mile (measured on the AC side) on my 2800lb
>> Porsche 914 should be 1900/2800 x 330 = 224 whr per mile in a lighter
>> Ghia-etc.
>
> I don't think energy usage scales this way with weight. True, you're
> accelerating less mass, but acceleration is only part of what drains the
> battery. And while weight affects rolling resistance, there are other
> components of rolling resistance that I don't think it does (I could be
> wrong). Weight has no effect at all on aero drag, AFAIK.
>
> So while a lighter vehicle will certainly use less energy, I don't think the
> improvement will be as dramatic as you hope.

It will be interesting to see how the Edison2 Very Light Car electric version will do. Oliver Kuttner has mentioned he hopes it to weight 1,300 pounds (or less) and have a 12-16kWh lithium pack. If any car can get >100Wh/mile, the VLCe will. (I'm hoping my CarBEN EV will, too!)

Having said that, I think that aerodynamics are more important than weight. Weight = momentum, so you get better coasting and better regenerative braking with more weight, so being overweight is not good, but saving every last ounce is not as critical as getting the drag as low as possible.

Also, drivetrain efficiency (which EV's have in abundance), is the most important of all, I think.

Sincerely, Neil
http://neilblanchard.blogspot.com/


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Discussion Starter #12
Aerodynamic drag is a subset of overall drag. I meant that tire drag = rolling
resistance. Rolling resistance is a form of drag (as would be brake drag from
dragging brakes).


Side note, even though I wasn't talking about it before, tires do also exhibit
aerodynamic drag. I met a guy on the Salt Flats that could go 130 mph with
aerodynamic skinnies. He switched back to his twice as wide autocross tires and
went 120 mph, 10 mph slower. Tire aerodynamic drag is a big effect at those
speeds, but not much of an effect at typical commute speeds. Tire drag due to
rolling resistance, however, is a big effect and directly proportional to
weight.



________________________________
From: Cor van de Water <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Tue, October 19, 2010 12:40:14 PM
Subject: Re: [EVDL] Lightweight Most Efficient Conversion

Eh, not entirely.

The *tire* drag may be somewhat related to weight
but (especially at higher speeds) the aero drag
is completely unrelated except where weight
translates into a bigger car (more frontal area)
or worse Cd or the ride height changes and this
affects aero drag, but other than those secondary
effect, higher weight will have only two immediate effects:
- increase tire rolling resistance (larger deflection)
- increase kinetic energy (more mass to accelerate)
so acceleration will be slower and/or consume more
energy to achieve the same speed.
With regen braking you can roughly re-capture half
the kinetic energy back into the battery pack, to
be re-used for your next acceleration....
In case no re-gen is present, all kinetic energy will
be lost at your next stop, so this also turns a higher
weight into higher losses.

Hope this clarifies,

Cor van de Water
Director HW & Systems Architecture Group
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [email protected]
Tel: +1 408 383 7626 VoIP: +31 20 3987567 FWD# 25925
Tel: +91 (040)23117400 x203 XoIP: +31877841130

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of David Dymaxion
Sent: Tuesday, October 19, 2010 11:26 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Lightweight Most Efficient Conversion

Rolling resistance is directly proportional to weight -- double the
weight double the drag. The nonlinear terms are very small and safely
neglected. This translates directly for low speeds, so for a city speeds
a lighter car is definitely better, and the Whr/mi will directly scale.
At highway speeds about
1/2 your drag is air resistance, in that case weight is less of an
effect.


For Mark at low speeds it will drop from 330 whr / mi to 224 whr / mi,
but at highway speeds the drop might be just something like 330 to 280
Whr/mi (or better or worse depending on speed). Of course this assume
tires with the same rolling resistance, equally well aligned
suspensions, etc.



________________________________
From: EVDL Administrator <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Tue, October 19, 2010 11:12:54 AM
Subject: Re: [EVDL] Lightweight Most Efficient Conversion

On 19 Oct 2010 at 8:44, Mark Hanson wrote:

> I figure at 330whr per mile (measured on the AC side) on my 2800lb
> Porsche 914 should be 1900/2800 x 330 = 224 whr per mile in a lighter
> Ghia-etc.

I don't think energy usage scales this way with weight. True, you're
accelerating less mass, but acceleration is only part of what drains the
battery. And while weight affects rolling resistance, there are other
components of rolling resistance that I don't think it does (I could be
wrong). Weight has no effect at all on aero drag, AFAIK.

So while a lighter vehicle will certainly use less energy, I don't think
the improvement will be as dramatic as you hope.

That said, Ghias have a rep for being real WH sippers in the EV world.
(But then so do Porsche 914s.)

It seems to me that you've been looking for the "holy grail" in
economical, efficient EV commuting for many years. You might want to
take a look at some old Solectria Forces for ideas. James Worden was
just about fanatical about minimizing energy usage. He used a low
friction, lightweight aluminum transaxle and a high efficiency AC
induction drive with lots of regen, and kept the converted weight in the
early cars to 2100lb (later cars were closer to 2500lbs, IIRC). Forces
would use ~150-160 Wh/mi (at the battery) at a steady 45mph.

David Roden - Akron, Ohio, USA
EVDL Administrator

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL
Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = =
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Note: mail sent to "evpost" and "etpost" addresses will not reach me.
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webpage http://www.evdl.org/help/ .
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Discussion Starter #13
Steven Ciciora suggested:
> If you have some pulse train that is proportional to velocity

Ha! finally a good reason to hack into your ABS sensor(s) besides
detecting low tire pressure from difference in circumference, now
you can also use it to measure your drag!

Cor van de Water
Director HW & Systems Architecture Group
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [email protected]
Tel: +1 408 383 7626 VoIP: +31 20 3987567 FWD# 25925
Tel: +91 (040)23117400 x203 XoIP: +31877841130

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Discussion Starter #14
PS

I wrote:

> It will be interesting to see how the Edison2 Very Light Car electric version will do. Oliver Kuttner has mentioned he hopes it to weight 1,300 pounds (or less) and have a 12-16kWh lithium pack. If any car can get >100Wh/mile, the VLCe will. (I'm hoping my CarBEN EV will, too!)
>
> Having said that, I think that aerodynamics are more important than weight. Weight = momentum, so you get better coasting and better regenerative braking with more weight, so being overweight is not good, but saving every last ounce is not as critical as getting the drag as low as possible.
>
> Also, drivetrain efficiency (which EV's have in abundance), is the most important of all, I think.


I meant to add that Dave Cloud's Dolphin seems to be the best indicator that aerodynamic drag trumps weight.

Sincerely, Neil
http://neilblanchard.blogspot.com/


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Discussion Starter #15
Hi Mark,

I actually have a 1993 Honda del Sol that was converted with an ADC 9"
motor, Kelly KDHD controller, 14 KWh of Thundersky cells (45 100Ah cells).
If you want to chat to compare notes, let me know!

The bad news is that the del Sol is quite a bit heavier than you could have
imagined. Most web sources put its stock curb weight around 2300 pounds.
It also isn't very aerodynamic. The blunt back of the cab makes a really
cool convertible with a roll-bar feel, but it also causes quite a bit of
drag. My Mazda 626 has a lower Cd than the del Sol.

However, the good news is that I'm getting around 225-250 Wh/mile from it.
(Mix of driving with 60 mph highway and stop&go city on a 25 mile one-way
commute.) I actually think I should do better because the del Sol isn't
coasting very well right now. I've noticed the wheels are hard to turn by
hand, so I'm going to check the bearings. The del Sol coasts down much
faster than my 626 out of gear. I don't think the aerodynamics account for
all of that.

With some issues in my battery pack with balance, I achieved 50 miles range.
I think 60 miles is the top end of range with my setup. Performance isn't
great, but it's almost impressive. I don't think anybody on the road knows
it's electric from the performance. The controller isn't high performance
(pretty much wimps out after 200A for any period of time, but that's about
all the batteries would like to provide anyway.)

I didn't do the original conversion, but I'm fairly familiar with it and I'm
still in contact with the original owner. The trunk can fit 20 cells and
still have room to mount the removable hard top roof. You still have about
1/2 the trunk space too.

If you want to see pictures, the original converter had a blog page with
good details. It is http://mt-ev.blogspot.com
The car is also in evalbum at: http://www.evalbum.com/2778

Mike

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Mark Hanson
Sent: Tuesday, October 19, 2010 6:45 AM
To: [email protected]
Subject: [EVDL] Lightweight Most Efficient Conversion


Hi Folk's,

I was thinking (it can happen) about taking my 10kwh worth of Thundersky
batts ($5k 32ea 100ah) out of the E-Cat www.evalbum.com/2749 , selling my
E-Porsche www.evalbum.com/1273 ,$7k and putting the 200lb battery pack
LiFePO4 3.3V x 32 = 106V (wire in series instead of buddy pairs) into a 1700
lb Karman Ghia (maybe Honda Del-Sol if same weight), finish weight 1900lb.
I have an E-Tek RT 72V PM motor, curious how that would do in an EV, maybe
to small. But that would be a peppy lightweight conversion. Not sure if
the LiFePO4 batteries will go less than 80% dod and the max current 200A
have to check with Thundersky (or Dave Kois from evcomponents where I bought
but I think they fizzled.) I figure at 330whr per mile (measured on the AC
side) on my 2800lb Porsche 914 should be 1900/2800 x 330 = 224 whr per mile
in a lighter Ghia-etc. So at 80% dod 80ah x 3.3V x 32 = 8448 whr / 224 = 37
miles range, maybe that's wishful thinking on a 200lb lightweight pack, I
dunno but looks g!
ood on paper :)

I finished putting in all the fusible links between the batteries, 4 sizes
smaller (#12) than the main (#8) with hypalon fireproof insulation but
normal copper wire inside (in E-Cat), 150A main breaker. I noticed that the
wire lengths have to be "tuned" to the same length between the buddy pairs,
the previous 60A buddy pair fuses were darkenned (probably getting ready to
pop) on the shorter wires of non tuned buddy pairs. So this time I was
careful to make the buddy pair wires the same length even if one terminal
was closer to the next battery than the other. This current upgrade was for
converting a Johnson 9.9hp 1gph sailmaster to electric with the Etek-RT
motor but now I'm thinking of maybe going over to the "dark side" and just
using it as gas since I'm hitting that little laws of physics thingy: hull
speed mph = 1.5 x sqr-root of hull length (18') or 6.4mph so above 4hp it
ramps up exponentially, need a 25hp to go twice as fast (my kid wants to go
faster, kneeboard/s!
ki). Then I would free up the lithium stuff for a lightweight conversion,
no more overweight lead sleds with 16-20 Trojans for me with poor
braking/handling.

Have a renewable energy day,
mark
www.reevadiy.org community service RE & EV's
The 3 leg stool is solar,wind & EV's
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Discussion Starter #16
Mike,
That sounds like some serious drag, probably by the brakes.
What I am used to is not whether you can turn a wheel by hand
but how many turns will it complete after you stop pushing
the wheel around....
If it stops (almost) instantly no matter how hard you turn it,
then you need to look at brake drag (pry something between the
brake shoes and move them away from the disk, or with drum
brakes, make sure the shoes move freely and do not jam against
the drum for some reason. Indeed the other reason may be the
bearing, but you can have pretty bad bearings and still drive
fine (with only a little extra noise).

The driven wheels can have additional drag from the gearbox
(thick/cold oil) and since an EV barely has time to warm up
the oil in the gearbox, it makes sense to put lighter weight
oil in there to reduce drag.

I presume you do this test when in Neutral, so we do not have
to account for the drivetrain upstream of the gearbox.

In pickup trucks and vans an additional loss source is the
differential in the rear axle - also there it makes sense to
use a lighter oil.

Success,

Cor van de Water
Director HW & Systems Architecture Group
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [email protected]
Tel: +1 408 383 7626 VoIP: +31 20 3987567 FWD# 25925
Tel: +91 (040)23117400 x203 XoIP: +31877841130

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Mike Nickerson
Sent: Wednesday, October 20, 2010 10:40 AM
To: 'Electric Vehicle Discussion List'
Subject: Re: [EVDL] Lightweight Most Efficient Conversion

Hi Mark,

I actually have a 1993 Honda del Sol that was converted with an ADC 9"
motor, Kelly KDHD controller, 14 KWh of Thundersky cells (45 100Ah
cells).
If you want to chat to compare notes, let me know!

The bad news is that the del Sol is quite a bit heavier than you could
have imagined. Most web sources put its stock curb weight around 2300
pounds.
It also isn't very aerodynamic. The blunt back of the cab makes a
really cool convertible with a roll-bar feel, but it also causes quite a
bit of drag. My Mazda 626 has a lower Cd than the del Sol.

However, the good news is that I'm getting around 225-250 Wh/mile from
it.
(Mix of driving with 60 mph highway and stop&go city on a 25 mile
one-way
commute.) I actually think I should do better because the del Sol isn't
coasting very well right now. I've noticed the wheels are hard to turn
by hand, so I'm going to check the bearings. The del Sol coasts down
much faster than my 626 out of gear. I don't think the aerodynamics
account for all of that.

With some issues in my battery pack with balance, I achieved 50 miles
range.
I think 60 miles is the top end of range with my setup. Performance
isn't great, but it's almost impressive. I don't think anybody on the
road knows it's electric from the performance. The controller isn't
high performance (pretty much wimps out after 200A for any period of
time, but that's about all the batteries would like to provide anyway.)

I didn't do the original conversion, but I'm fairly familiar with it and
I'm still in contact with the original owner. The trunk can fit 20
cells and still have room to mount the removable hard top roof. You
still have about
1/2 the trunk space too.

If you want to see pictures, the original converter had a blog page with
good details. It is http://mt-ev.blogspot.com The car is also in
evalbum at: http://www.evalbum.com/2778

Mike

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Mark Hanson
Sent: Tuesday, October 19, 2010 6:45 AM
To: [email protected]
Subject: [EVDL] Lightweight Most Efficient Conversion


Hi Folk's,

I was thinking (it can happen) about taking my 10kwh worth of Thundersky
batts ($5k 32ea 100ah) out of the E-Cat www.evalbum.com/2749 , selling
my E-Porsche www.evalbum.com/1273 ,$7k and putting the 200lb battery
pack
LiFePO4 3.3V x 32 = 106V (wire in series instead of buddy pairs) into a
1700 lb Karman Ghia (maybe Honda Del-Sol if same weight), finish weight
1900lb.
I have an E-Tek RT 72V PM motor, curious how that would do in an EV,
maybe to small. But that would be a peppy lightweight conversion. Not
sure if the LiFePO4 batteries will go less than 80% dod and the max
current 200A have to check with Thundersky (or Dave Kois from
evcomponents where I bought but I think they fizzled.) I figure at
330whr per mile (measured on the AC
side) on my 2800lb Porsche 914 should be 1900/2800 x 330 = 224 whr per
mile in a lighter Ghia-etc. So at 80% dod 80ah x 3.3V x 32 = 8448 whr /
224 = 37 miles range, maybe that's wishful thinking on a 200lb
lightweight pack, I dunno but looks g!
ood on paper :)

I finished putting in all the fusible links between the batteries, 4
sizes smaller (#12) than the main (#8) with hypalon fireproof insulation
but normal copper wire inside (in E-Cat), 150A main breaker. I noticed
that the wire lengths have to be "tuned" to the same length between the
buddy pairs, the previous 60A buddy pair fuses were darkenned (probably
getting ready to
pop) on the shorter wires of non tuned buddy pairs. So this time I was
careful to make the buddy pair wires the same length even if one
terminal was closer to the next battery than the other. This current
upgrade was for converting a Johnson 9.9hp 1gph sailmaster to electric
with the Etek-RT motor but now I'm thinking of maybe going over to the
"dark side" and just using it as gas since I'm hitting that little laws
of physics thingy: hull speed mph = 1.5 x sqr-root of hull length (18')
or 6.4mph so above 4hp it ramps up exponentially, need a 25hp to go
twice as fast (my kid wants to go faster, kneeboard/s!
ki). Then I would free up the lithium stuff for a lightweight
conversion, no more overweight lead sleds with 16-20 Trojans for me with
poor braking/handling.

Have a renewable energy day,
mark
www.reevadiy.org community service RE & EV's
The 3 leg stool is solar,wind & EV's

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Discussion Starter #17
I'm not sure that weight is a secondary factor. Not much driving is done at
constant speed on level ground. Here in Nova Scotia, there is little level
roadway, steady state throttle is nearly impossible. Acceleration takes
place frequently so weight is important.

When I raced stock outboard boats, one of the national champions tested
every variable. He added weight past the minimum just to see. He claimed an
extra 15 lbs. cost an mph. This may be due to constant acceleration from one
corner to the next, but in a limited performance envelope ( 15 cu in, 60mph
) I think a boat peaks part way down the straight and is steady state until
the next turn.

I'm importing a Suzuki Carry ( street legal in Canada) to convert. It has
reasonably low frontal area but I can't find the cx. The thing that
attracted me was the 1500 lb. weight. That means 1200 before adding motor,
controller, wire and batteries. I'm shooting for 1900lb done. You 'need
lots of rpms for the 6:20 diff so I bought an aircraft generator. I plan to
start with a 45 mph local driver at 48 volts and see if I need to go higher.
98 volts ( maybe 2 packs) is optimal to integrate with the battery bank for
my wind turbine. The truck should serve as an extra emergency power source.
120 volts of solar panels going on the roof next spring should give me a
free drive to the beer store once a week.

About the boat. Am I remembering correctly ; a 16x16 prop. This seems pretty
big to me. A smaller prop may produce better performance. An A Stock Hydro
with a 15hp engine, 330lb and 7200 rpm would run 63mph in competition with
good acceleration using a 6X9 prop.

John McManus




Cor van de Water <[email protected]> wrote:

> Mike,
> That sounds like some serious drag, probably by the brakes.
> What I am used to is not whether you can turn a wheel by hand
> but how many turns will it complete after you stop pushing
> the wheel around....
> If it stops (almost) instantly no matter how hard you turn it,
> then you need to look at brake drag (pry something between the
> brake shoes and move them away from the disk, or with drum
> brakes, make sure the shoes move freely and do not jam against
> the drum for some reason. Indeed the other reason may be the
> bearing, but you can have pretty bad bearings and still drive
> fine (with only a little extra noise).
>
> The driven wheels can have additional drag from the gearbox
> (thick/cold oil) and since an EV barely has time to warm up
> the oil in the gearbox, it makes sense to put lighter weight
> oil in there to reduce drag.
>
> I presume you do this test when in Neutral, so we do not have
> to account for the drivetrain upstream of the gearbox.
>
> In pickup trucks and vans an additional loss source is the
> differential in the rear axle - also there it makes sense to
> use a lighter oil.
>
> Success,
>
> Cor van de Water
> Director HW & Systems Architecture Group
> Proxim Wireless Corporation http://www.proxim.com
> Email: [email protected] Private: http://www.cvandewater.com
> Skype: cor_van_de_water IM: [email protected]
> Tel: +1 408 383 7626 VoIP: +31 20 3987567 FWD# 25925
> Tel: +91 (040)23117400 x203 XoIP: +31877841130
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Mike Nickerson
> Sent: Wednesday, October 20, 2010 10:40 AM
> To: 'Electric Vehicle Discussion List'
> Subject: Re: [EVDL] Lightweight Most Efficient Conversion
>
> Hi Mark,
>
> I actually have a 1993 Honda del Sol that was converted with an ADC 9"
> motor, Kelly KDHD controller, 14 KWh of Thundersky cells (45 100Ah
> cells).
> If you want to chat to compare notes, let me know!
>
> The bad news is that the del Sol is quite a bit heavier than you could
> have imagined. Most web sources put its stock curb weight around 2300
> pounds.
> It also isn't very aerodynamic. The blunt back of the cab makes a
> really cool convertible with a roll-bar feel, but it also causes quite a
> bit of drag. My Mazda 626 has a lower Cd than the del Sol.
>
> However, the good news is that I'm getting around 225-250 Wh/mile from
> it.
> (Mix of driving with 60 mph highway and stop&go city on a 25 mile
> one-way
> commute.) I actually think I should do better because the del Sol isn't
> coasting very well right now. I've noticed the wheels are hard to turn
> by hand, so I'm going to check the bearings. The del Sol coasts down
> much faster than my 626 out of gear. I don't think the aerodynamics
> account for all of that.
>
> With some issues in my battery pack with balance, I achieved 50 miles
> range.
> I think 60 miles is the top end of range with my setup. Performance
> isn't great, but it's almost impressive. I don't think anybody on the
> road knows it's electric from the performance. The controller isn't
> high performance (pretty much wimps out after 200A for any period of
> time, but that's about all the batteries would like to provide anyway.)
>
> I didn't do the original conversion, but I'm fairly familiar with it and
> I'm still in contact with the original owner. The trunk can fit 20
> cells and still have room to mount the removable hard top roof. You
> still have about
> 1/2 the trunk space too.
>
> If you want to see pictures, the original converter had a blog page with
> good details. It is http://mt-ev.blogspot.com The car is also in
> evalbum at: http://www.evalbum.com/2778
>
> Mike
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Mark Hanson
> Sent: Tuesday, October 19, 2010 6:45 AM
> To: [email protected]
> Subject: [EVDL] Lightweight Most Efficient Conversion
>
>
> Hi Folk's,
>
> I was thinking (it can happen) about taking my 10kwh worth of Thundersky
> batts ($5k 32ea 100ah) out of the E-Cat www.evalbum.com/2749 , selling
> my E-Porsche www.evalbum.com/1273 ,$7k and putting the 200lb battery
> pack
> LiFePO4 3.3V x 32 = 106V (wire in series instead of buddy pairs) into a
> 1700 lb Karman Ghia (maybe Honda Del-Sol if same weight), finish weight
> 1900lb.
> I have an E-Tek RT 72V PM motor, curious how that would do in an EV,
> maybe to small. But that would be a peppy lightweight conversion. Not
> sure if the LiFePO4 batteries will go less than 80% dod and the max
> current 200A have to check with Thundersky (or Dave Kois from
> evcomponents where I bought but I think they fizzled.) I figure at
> 330whr per mile (measured on the AC
> side) on my 2800lb Porsche 914 should be 1900/2800 x 330 = 224 whr per
> mile in a lighter Ghia-etc. So at 80% dod 80ah x 3.3V x 32 = 8448 whr /
> 224 = 37 miles range, maybe that's wishful thinking on a 200lb
> lightweight pack, I dunno but looks g!
> ood on paper :)
>
> I finished putting in all the fusible links between the batteries, 4
> sizes smaller (#12) than the main (#8) with hypalon fireproof insulation
> but normal copper wire inside (in E-Cat), 150A main breaker. I noticed
> that the wire lengths have to be "tuned" to the same length between the
> buddy pairs, the previous 60A buddy pair fuses were darkenned (probably
> getting ready to
> pop) on the shorter wires of non tuned buddy pairs. So this time I was
> careful to make the buddy pair wires the same length even if one
> terminal was closer to the next battery than the other. This current
> upgrade was for converting a Johnson 9.9hp 1gph sailmaster to electric
> with the Etek-RT motor but now I'm thinking of maybe going over to the
> "dark side" and just using it as gas since I'm hitting that little laws
> of physics thingy: hull speed mph = 1.5 x sqr-root of hull length (18')
> or 6.4mph so above 4hp it ramps up exponentially, need a 25hp to go
> twice as fast (my kid wants to go faster, kneeboard/s!
> ki). Then I would free up the lithium stuff for a lightweight
> conversion, no more overweight lead sleds with 16-20 Trojans for me with
> poor braking/handling.
>
> Have a renewable energy day,
> mark
> www.reevadiy.org community service RE & EV's
> The 3 leg stool is solar,wind & EV's
>
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Discussion Starter #18
You can take the TS cells to more than 80% DoD, but only if you are willing
to significantly reduce their cycle life. Staying above 20% SOC is
recommended, and above 30% gives longer life according to the manufacturer's
spec. I have a Suzuki Swift, curb weight about 1990 lb, finished ev weight
about 2250 lb with 36 180Ah CALB cells. Drag coeff. 0.32, area ~18 square
ft area. HPEVS AC50 motor with regen. I get about 190 to 215 Wh/mile in
mixed highway (60 mph)/secondary road (35-40 mph) driving. At the low end
in summer, high end in winter (with heater). For example, a few days ago I
drove 58 miles, about half on highways at 55 -65 mph, and half at 35 - 45
mph, and used 204.8 Wh/mile from the wall (measured with EKM meter at AC
input to the charger). Assuming around 94% charger efficiency (Manzanita
PFC30), that would be around 193 Wh/mile. I think the Del Sol is heavier
than you think, and it also has a higher drag coeff due to turbulence at
that abrupt rear window. Dave has his own company now, currentev.
--
View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Lightweight-Most-Efficient-Conversion-tp3002052p3003881.html
Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.

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Discussion Starter #19
John McManus wrote:
> I'm not sure that weight is a secondary factor. Not much driving is done at
> constant speed on level ground. Here in Nova Scotia, there is little level
> roadway, steady state throttle is nearly impossible. Acceleration takes
> place frequently so weight is important.

Energy that is put into acceleration and hill climbing is mostly
recoverable if you can avoid squandering it by using friction brakes.

--
Willie, ONWARD! Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime 38 days 7 hours 15 minutes

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Discussion Starter #20
Willie:
I use a lot of throttle ( gas engine) to climb a hill and then , if
coasting with no throttle - sometimes out of gear-) lose speed all the way
down due to aero and mechanical drive. Wouldn't regeneration slow the
vehicle further needing ever more energy to climb the next hill.

Willie McKemie <[email protected]> wrote:

> On Wed, Oct 20, 2010 at 10:42:12AM -0300, John McManus wrote:
> > I'm not sure that weight is a secondary factor. Not much driving is done
> at
> > constant speed on level ground. Here in Nova Scotia, there is little
> level
> > roadway, steady state throttle is nearly impossible. Acceleration takes
> > place frequently so weight is important.
>
> Energy that is put into acceleration and hill climbing is mostly
> recoverable if you can avoid squandering it by using friction brakes.
>
> --
> Willie, ONWARD! Through the fog!
> http://counter.li.org Linux registered user #228836 since 1995
> Debian3.1/GNU/Linux system uptime 38 days 7 hours 15 minutes
>
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