EV Digest 7012
Topics covered in this issue include:
1) hElix EV update
by "Tehben Dean" <[EMAIL PROTECTED]>
2) Battery Boxes and Heating
by "Tehben Dean" <[EMAIL PROTECTED]>
3) RE: Speed Reducers in the Nose
by "Roger Stockton" <[EMAIL PROTECTED]>
4) Re: Battery Boxes and Heating
by "Zeke Yewdall" <[EMAIL PROTECTED]>
5) Catch Phrases
by Larry Licata <[EMAIL PROTECTED]>
6) Re: AGM vs Gel
by "Joseph T. " <[EMAIL PROTECTED]>
7) Re: Ideal EV configuration for my situation?
by "Joseph T. " <[EMAIL PROTECTED]>
8) Re: Catch Phrases
by "Joseph T. " <[EMAIL PROTECTED]>
9) RE: Battery Boxes and Heating
by "Alan Brinkman" <[EMAIL PROTECTED]>
10) Re: Battery Boxes and Heating
by "Tehben Dean" <[EMAIL PROTECTED]>
11) RE: conversion question - rolling resistance
by "Phil Marino" <[EMAIL PROTECTED]>
12) RE: Battery Boxes and Heating
by "Alan Brinkman" <[EMAIL PROTECTED]>
13) RE: Catch phrase for the EVDL
by Jeff Shanab <[EMAIL PROTECTED]>
14) Re: Battery Boxes and Heating
by "Roland Wiench" <[EMAIL PROTECTED]>
15) Re: Battery Boxes and Heating
by "Roland Wiench" <[EMAIL PROTECTED]>
16) Re: Battery Boxes and Heating
by "Tehben Dean" <[EMAIL PROTECTED]>
17) RE: conversion question
by "Tom S." <[EMAIL PROTECTED]>
18) Efficiency of lead acid batteries
by Dan Frederiksen <[EMAIL PROTECTED]>
19) Re: a little thought problem for the list
by "Zeke Yewdall" <[EMAIL PROTECTED]>
20) Re: Efficiency of lead acid batteries
by "Joseph T. " <[EMAIL PROTECTED]>
21) Re: conversion question - rolling resistance
by "Joseph T. " <[EMAIL PROTECTED]>
22) Re: Short Range Battery Pack
by "Ev Performance (Robert Chew)" <[EMAIL PROTECTED]>
23) Re: Ideal EV configuration for my situation?
by "Matthew Chan" <[EMAIL PROTECTED]>
24) RE: conversion question
by [EMAIL PROTECTED]
25) Re: Ideal EV configuration for my situation?
by "Matthew Chan" <[EMAIL PROTECTED]>
26) Re: Battery Boxes and Heating
by Danny Miller <[EMAIL PROTECTED]>
27) Re: conversion question - rolling resistance
by Danny Miller <[EMAIL PROTECTED]>
--- Begin Message ---
Well my Siemens parts arrived last week... very exciting! :)
I have also removed the bed, exhaust and fuel tank from my truck and
am ready to pull the engine. I have everything (almost) unhooked and
am just waiting on a friend and his friends engine hoist ;)
I am still having a dilemma with the adapter. :( The only decision in
that arena is I am going to wait till the engine is out and make sure
that my motor will clear the front T-case, steering arms and
everything 8-\
I have decided (most likely) to use 26 8G31DTM Deka Dominators. They
have 64Ah 1hr rate @ 70lbs each. So that is 1820lb pack and about
10kwh to 50%DOD Sound good?
I think I might build a flatbed because I can't get all those batt's
under my stock one.
I am hoping to have a website up in the next couple of weeks.
Thanks everybody,
--
Tehben
'90 Toyota 4x4 Pickup
'hElix EV'
evalbum: http://www.austinev.org/evalbum/1225
--- End Message ---
--- Begin Message ---
I am thinking about making angle iron (what size of angle iron is
recommended?) trays and then welding up sheet metal battery boxes that
set in them.
Sound like a plan?
What is generally used for insulation?
For battery heating will they stay warm when you charge them and then
when they are being drawn from? or is it recommended to put warmers in
the boxes?
Thanks,
--
Tehben
'90 Toyota 4x4 Pickup
'hElix EV'
evalbum: http://www.austinev.org/evalbum/1225
--- End Message ---
--- Begin Message ---
MIKE WILLMON wrote:
> I wonder if those Rotax 3:1 gear boxes could be adapted to an
> 8"/9" end housing?
Which ones are those? (Got a link?) I think 3:1 is a better ratio than
common overdrive type gearsets, and the Rotax might even be affordable.
Thanks,
Roger.
--- End Message ---
--- Begin Message ---
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* ---REMAINDER OF MESSAGE TRUNCATED--- *
* This post contains a forbidden message format *
* (such as an attached file, a v-card, HTML formatting) *
* Lists at sjsu.edu only accept PLAIN TEXT *
* If your postings display this message your mail program *
* is not set to send PLAIN TEXT ONLY and needs adjusting *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
--- End Message ---
--- Begin Message ---
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* ---REMAINDER OF MESSAGE TRUNCATED--- *
* This post contains a forbidden message format *
* (such as an attached file, a v-card, HTML formatting) *
* Lists at sjsu.edu only accept PLAIN TEXT *
* If your postings display this message your mail program *
* is not set to send PLAIN TEXT ONLY and needs adjusting *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
--- End Message ---
--- Begin Message ---
I don't have any hands on experience with EVs but this is what I here:
AGMs are good for power, not good for deep cycling or range. Going
over 50% DOD shouldn't be done.
Gels are not good for power, they give very few amps. They are better
than AGMs for deep cycling or range. I'm not sure if they are worse
than flooded though when it comes to deep cycling or range. They are
lighter however, and are used for AC systems since AC systems use few
amps, but high voltage.
On 7/10/07, Tehben Dean <[EMAIL PROTECTED]> wrote:
This is from the Deka battery manual:
Typical* VRLA Battery Cycling Ability vs. Depth of Discharge
Typical Life Cycles
Capacity Withdrawn
Gel AGM
100% 450 150
80% 600 200
50% 1000 370
25% 2100 925
10% 5700 3100
So If I ran gels to 100%DOD I would have more life than AGM's at 50%DOD???
On 6/30/07, Mike Willmon <[EMAIL PROTECTED]> wrote:
> Tehben,
> No doubt his supplier is John Gonzolas at Auto Electric & Battery. He has
the Alaska EVA set up with an account and will give you
> the good guy pricing if you mention you're a member of the AlaskaEVA group.
Baically what it comes down to is you'll pay their
> wholesale price plus a very small markup and they pick up the shipping (which
can be $30-$40 a battery) with their normal stock
> orders that come in every couple weeks. If you want I can give you John's
contact info and you can talk to him directly. He can
> either hold them for you if you want to pick them up or help you make
arrangements to truck them down. I'd be hapy to help in
> that regard as well, except my truck would barely make it to Girdwood :-( I
was originally going with the Deka Gels but talked
> myself into the better performance for the first run. I may go back to him
for gells when I'm done with this set of flooded Crown
> batteries.
>
> Mike
>
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> > Behalf Of Tehben Dean
> > Sent: Saturday, June 30, 2007 9:36 AM
> > To: ev@listproc.sjsu.edu
> > Subject: Re: AGM vs Gel
> >
> >
> > I was just in a local alternator and battery shop to see what was
> > available. He does carry Deka's, so if I do go with the gels I can get
> > them from him.
> > anyways he called his supplier in Anchorage to get a price quote on
> > the AGM and Gel Deka's and told the guy what I was going to use them
> > for. His supplier recommended Gel for an EV <shrug> he also gave him
> > the name of a guy I should contact who is an EV specialist in
> > Anchorage, named Mike Willmon :D
> >
> > When buying so many batteries does it make sense to try and get them
> > from the supplier at wholesale cost.. is it even possible?
> >
> > Cheers,
> > --
> > Tehben
> > '90 Toyota 4x4 Pickup
> > 'hElix EV'
> > evalbum: http://www.austinev.org/evalbum/1225
> >
> >
>
>
--
Tehben
'90 Toyota 4x4 Pickup
'hElix EV'
evalbum: http://www.austinev.org/evalbum/1225
--- End Message ---
--- Begin Message ---
I've been wondering about something similar.
In the EV calculators they give you the range for different mph at
steady speeds.
To take in account acceleration and declaration what mph range number
should be used for the "real world" range in city traffic similar to:
http://fueleconomy.gov/feg/fe_test_schedules.shtml
I'm thinking since the average speed is around 35 mph that 50mph range
number should be chosen.
On 7/10/07, Peter VanDerWal <[EMAIL PROTECTED]> wrote:
> Hi guys, just one more question for the moment. I've been using uve's
> calculator today and it says that I can have a 91 mile range at
> 100km/h (60m/h)! How accurate is this calculator? Does it account for
> losses due to acceleration/deceleration, etc? If this is true, I might
> not need to change the donor vehicle after all, assuming that the
> vehicle can hold 1500lbs of batteries.
Accuracy is fair to middlen. Range figures do NOT take acceleration into
account, they are for a steady speed with no stops.
>
> Also, when the range is calculated, does it use 100%DOD, or 80% or
100% DoD and even then are only close to accurate for a new pack.
Also, unless you change the values, this assumes no wind and flat ground.
Change the incline to 4% and see what happens when you hit mild hills.
> Lastly, I seem to be getting the best range at 1st gear for
> everything. The mercedes service rep said that it is possible to
Look at the motor RPMs. The sweet spot (efficiency) on most, EV size,
series wound motors is around 3000-4000.
The calculator uses simple equations to model the motor. These equations
are more accurate at the middle of the curve than they are towards the
edges. I.e. they are more accurate when the motor is near it's sweet
spot.
--
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 ---
Switch to g-mail and select plain formatting so that we can read your
e-mails because some of us can't read them since it's in rich
formatting.
On 7/10/07, Larry Licata <[EMAIL PROTECTED]> wrote:
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* ---REMAINDER OF MESSAGE TRUNCATED--- *
* This post contains a forbidden message format *
* (such as an attached file, a v-card, HTML formatting) *
* Lists at sjsu.edu only accept PLAIN TEXT *
* If your postings display this message your mail program *
* is not set to send PLAIN TEXT ONLY and needs adjusting *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
--- End Message ---
--- Begin Message ---
Tehben,
Allan Poulsen of Ottawa, Ontario Canada, in his EV Album listing:
http://www.austinev.org/evalbum/600.html says he uses: "Winterized
battery box (2" foam insulation on all sides) and 300 Watts of battery
heaters (thermostat controlled) keeps batteries in good temperature
range in winter ( >20C, even when -35C outside!)." I recently read
where someone just used the insulation, no heaters, and relied upon
charging and discharging to supply heat, and got along well. You may be
able to search the E-mail archives or the EV Album and find that
comment.
Alan Brinkman
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Tehben Dean
Sent: Tuesday, July 10, 2007 5:07 PM
To: evlist
Subject: Battery Boxes and Heating
I am thinking about making angle iron (what size of angle iron is
recommended?) trays and then welding up sheet metal battery boxes that
set in them.
Sound like a plan?
What is generally used for insulation?
For battery heating will they stay warm when you charge them and then
when they are being drawn from? or is it recommended to put warmers in
the boxes?
Thanks,
--
Tehben
'90 Toyota 4x4 Pickup
'hElix EV'
evalbum: http://www.austinev.org/evalbum/1225
--- End Message ---
--- Begin Message ---
Has anyone used Prodex Total Insulation? foil-foam-foil 14.5 R Value
http://www.insulation4less.com/prodex_Ffmf.asp
--
Tehben
'90 Toyota 4x4 Pickup
'hElix EV'
evalbum: http://www.austinev.org/evalbum/1225
--- End Message ---
--- Begin Message ---
Tom
Unless a car has dragging brakes or faulty wheel bearings, tire drag
dominates the car's rolling resistance.
That drag depends on the particular tires, and the tire pressure, and the
total vehicle weight. Since tire drag is proportional to the load on each
tire, it doesn't matter how many tires you have, or how the weight is
distributed.
The next obvious question is : what brand, size, and model are your tires (
front and rear) ?
If you don't know, you can easily get this information from the sidewall of
the tires.
Being able to push it with one hand doesn't tell us much. If you couldn't
push it with one hand, it would there was a problem somewhere.
Phil Marino
From: "Tom S." <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: RE: conversion question
Date: Tue, 10 Jul 2007 19:00:41 -0400 (EDT)
Hi Rodger,
I disagree. I can push my car easily with one hand of a level street, I
don`t think you can do that with a standard car. I`ve been testing this
car for years,and could make many claims, however without an official it
wood be meaningless, so i`ll just stick to the facts about the car.OK
Tom Sines
_________________________________________________________________
http://liveearth.msn.com
--- End Message ---
--- Begin Message ---
Tehben,
The R value of 14.5 seems quite high for quarter inch foam. At the
bottom of the web site they mention that the R value depends upon air
space and the heat conductivity of surrounding materials. Polyethylene
foam is about R 3 per inch so 1/4 inch is R 0.75 They are relying upon
air space and surrounding material to get their R value.
Alan Brinkman
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Tehben Dean
Sent: Tuesday, July 10, 2007 6:12 PM
To: ev@listproc.sjsu.edu
Subject: Re: Battery Boxes and Heating
Has anyone used Prodex Total Insulation? foil-foam-foil 14.5 R Value
http://www.insulation4less.com/prodex_Ffmf.asp
--
Tehben
'90 Toyota 4x4 Pickup
'hElix EV'
evalbum: http://www.austinev.org/evalbum/1225
--- End Message ---
--- Begin Message ---
"This car has lots of potential" :-)
--- End Message ---
--- Begin Message ---
Hello Tehben,
I do not use any extra heating for my batteries, except for the heat in the
building that the EV is in. Here in Montana, it is normal to get to 35
below.
I do not use steel, because steel has a R-factor of 0.5 per foot which has
too much conductance. It is like a heat sink for a battery.
I use 1/4 inch thick epoxy coated fiber glass battery boxes, which was
constructed out of 1/4 in. by 4 foot by 8 foot sheets. You can get these
from a custom fiberglass company. You can lay up the outside corners with
layers of cloth with resis. Do not lay up any cloth in the inside. Just
use fiberglass putty in the inside to fill the corners.
I use a 2 x 2 inch fiberglass angle on the top edge for the cover to lay
down on.
I coat the inside of the box with a Sink and TUB epoxy coating kit you can
get from Home Depot.
On the outside of the box, I glue on 2 inch thick Dow Corning blue foam
which has a 10 R-factor rating. I then cover all the foam surfaces with a
marine carport with a foam backing. There is a 4 inch dead air space all
around the sides of the box, except at the bottom, which is also laying on
another layer of 2 inch foam and carpet.
The battery box is slid into a pickup bed, which is also insulated with 2
inch of foam and cover with carpet. The 4 inch air space that is all round
the box also is a wireway for flexible conduits that hold all the power and
control wires.
At the rear of the battery box is a 16 inch wide equipment enclosure that
provides addition insulation.
The top covers are only foam back carpet insulated that has a large custom
made hinge hatch back cover that has a glass in it that acts like a passive
solar panel.
The battery box has a 2 inch PVC filter inlet pipe for air intake and a 2
inch PVC outlet pipe going to a acid proof all plastic exhaust fan that
exist out the bottom of the EV like a exhaust pipe.
The EV is always in a 80 R Factor building with 140 R factor ceilings and 20
R factor garage doors that maintains 70 degrees F. all year round, even its
35 below.
If the EV is only going to be out side for less than 4 hours at 35 below,
then I may raise the garage heat to 80 degrees, which only takes about 15
minutes before I leave. The battery box exhaust fans bring in this heat to
preheat the batteries.
The temperature inside the box will get down to 65 F. at 35 below if its
cloudy for about 4 hours. If its sunny, I will park the EV so the hatch
back panel is facing the sun, the battery box compartment will get to 80
degrees or more all day long.
To see this battery compartment:
http://www.austinev.org/evalbum/470.html
Roland
----- Original Message -----
From: "Tehben Dean" <[EMAIL PROTECTED]>
To: "evlist" <ev@listproc.sjsu.edu>
Sent: Tuesday, July 10, 2007 6:07 PM
Subject: Battery Boxes and Heating
> I am thinking about making angle iron (what size of angle iron is
> recommended?) trays and then welding up sheet metal battery boxes that
> set in them.
> Sound like a plan?
> What is generally used for insulation?
> For battery heating will they stay warm when you charge them and then
> when they are being drawn from? or is it recommended to put warmers in
> the boxes?
>
> Thanks,
> --
> Tehben
> '90 Toyota 4x4 Pickup
> 'hElix EV'
> evalbum: http://www.austinev.org/evalbum/1225
>
>
--- End Message ---
--- Begin Message ---
Do not use this type of insulation on the first layer that is next to the
ambient air. Best to use poly type which will not attain moisture. Roland
----- Original Message -----
From: "Tehben Dean" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, July 10, 2007 7:11 PM
Subject: Re: Battery Boxes and Heating
> Has anyone used Prodex Total Insulation? foil-foam-foil 14.5 R Value
> http://www.insulation4less.com/prodex_Ffmf.asp
>
> --
> Tehben
> '90 Toyota 4x4 Pickup
> 'hElix EV'
> evalbum: http://www.austinev.org/evalbum/1225
>
>
--- End Message ---
--- Begin Message ---
Yep, I was talking to my dad and that is what he said.
After some research is seems that Polyurethane rigid panel has the
highest R-value @ 6-7 per inch.
So Questioning anyone in a cold climate: What are you doing to keep
your batt's warm? What insulation and are you using and any heating
source other than charging and discharging?
Also for cost effectiveness and simplicity I think I will fold up the
sheet metal boxes and use sheet metal screws with some sort of rubbery
glue strips between the joints that my dad was showing me.
On 7/10/07, Alan Brinkman <[EMAIL PROTECTED]> wrote:
Tehben,
The R value of 14.5 seems quite high for quarter inch foam. At the
bottom of the web site they mention that the R value depends upon air
space and the heat conductivity of surrounding materials. Polyethylene
foam is about R 3 per inch so 1/4 inch is R 0.75 They are relying upon
air space and surrounding material to get their R value.
Alan Brinkman
--
Tehben
'90 Toyota 4x4 Pickup
'hElix EV'
evalbum: http://www.austinev.org/evalbum/1225
--- End Message ---
--- Begin Message ---
Hi Rodger,
I`ve worked on about 30 conversions, theres no way you can push a 4 wheel car
as easy as mine, we disagree again.
By the way here some facts about our car
There is no left and right front end suspension, tires, ball joints,tie
rods,steering wheel,steering column,gas engine,no transmission,and no beefed up
frame in the front of the car to hold this stuff.Thats at least a 1000lbs of
crap this car does not have.Now put batteries there instead. Too bad your
conversion has all that crap in it. There is no you can enough batteries in a
conversion.
Tom Sines
-----Original Message-----
>From: Peter VanDerWal <[EMAIL PROTECTED]>
>Sent: Jul 10, 2007 8:48 PM
>To: ev@listproc.sjsu.edu
>Subject: RE: conversion question
>
>Many people on the list can push their car with one hand. I seem to recall
>one (John Wayland?) or two mentioning they could do it with one finger.
>
>So I'd say that evidence is inconclusive.
>
>> Hi Rodger,
>>
>> I disagree. I can push my car easily with one hand of a level street, I
>> don`t think you can do that with a standard car. I`ve been testing this
>> car for years,and could make many claims, however without an official it
>> wood be meaningless, so i`ll just stick to the facts about the car.OK
>>
>> Tom Sines
>>
>> -----Original Message-----
>>>From: Roger Stockton <[EMAIL PROTECTED]>
>>>Sent: Jul 10, 2007 6:28 PM
>>>To: ev@listproc.sjsu.edu
>>>Subject: RE: conversion question
>>>
>>>Tom S. wrote:
>>>
>>>> Because this car is not a 4wheeler, but more like a two
>>>> wheeler I think the rolling resistance is up to 30% less.What
>>>> do you think?
>>>> Many of the parts a gas car we don`t.
>>>
>>>As a two wheeler you will 'save' the losses associated with the wheel
>>>bearing and brake drag on the missing front wheels. You will also save
>>>any rolling losses assoicated with non-ideal front end alignment ;^>
>>>
>>>Actual rolling resistance is going to be at least as great as a 4
>>>wheeler. The tires have some rolling resistance factor, which can be
>>>translated into a drag force as a fraction of the weight they are
>>>supporting. Say the coefficient of rolling resistance is 0.01; this
>>>means there will be 1lb of drag for every 100lbs on the wheel. If your
>>>two wheels have the same coefficient of rolling resistance as those on a
>>>typical 4-wheeled conversion of similar weight, then the drag due to
>>>rolling resistance will be the same. However, the wheels in the
>>>pictures of your vehicle look like they would be significantly greater
>>>rolling resistance than those of the typical conversion.
>>>
>>>I'm not even sure that you would save significantly on the brake drag;
>>>since you have only two wheels to stop a similar weight vehicle, you may
>>>need larger brakes and their drag may be similar to those of all 4
>>>wheels on a convnetional car. Do you use disks or drums? A typical
>>>conversion will have front disks and rear drums; most of the brake drag
>>>(and there may not be very much) will be due to the disks, so if you
>>>have disks your brake drag may be virtually the same as a tyipcal
>>>4-wheeler.
>>>
>>>Cheers,
>>>
>>>Roger.
>>>
>>
>>
>> ________________________________________
>> PeoplePC Online
>> A better way to Internet
>> http://www.peoplepc.com
>>
>>
>
>
>--
>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.
>
________________________________________
PeoplePC Online
A better way to Internet
http://www.peoplepc.com
--- End Message ---
--- Begin Message ---
I seem to recall a spec sheet once saying that at only 100A the lead
acid battery was only 50% efficient. are lead acids really that
inefficient for EV use?
do they really waste that much at only 100A?
and by implication does that mean a much more efficient battery type
like A123 can do just as good with half the capacity
Dan
--- End Message ---
--- Begin Message ---
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* ---REMAINDER OF MESSAGE TRUNCATED--- *
* This post contains a forbidden message format *
* (such as an attached file, a v-card, HTML formatting) *
* Lists at sjsu.edu only accept PLAIN TEXT *
* If your postings display this message your mail program *
* is not set to send PLAIN TEXT ONLY and needs adjusting *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
--- End Message ---
--- Begin Message ---
I've always heard lead-acid battery efficiency to be around 80-85% for
flooded and ~90% on AGMs. I never hear at what current though.....
On 7/10/07, Dan Frederiksen <[EMAIL PROTECTED]> wrote:
I seem to recall a spec sheet once saying that at only 100A the lead
acid battery was only 50% efficient. are lead acids really that
inefficient for EV use?
do they really waste that much at only 100A?
and by implication does that mean a much more efficient battery type
like A123 can do just as good with half the capacity
Dan
--- End Message ---
--- Begin Message ---
Rolling Resistance numbers on tires is tough to find. I've heard that
Consumer Reports rates them, but I'm not sure. I myself did alot of
research on this and found only one article giving some good numbers
on rolling resistance.
http://www.greenseal.org/resources/reports/CGR_tire_rollingresistance.pdf
Someone please tell us of other places where rolling resistance
numbers are published.
My consensus is that if you want to go for the outright lowest rolling
resistance, go for the B381 from Bridgestone. It's got the lowest
resistance score (which is good) These tires used to be used on the
old Honda Civic Hybrid. They're not used anymore, and I've heard that
the grip isn't so good.
The HTR 200 from Sumitomo is supposed to have great grip, while still
keeping a pretty decent rolling resistance number. The MXV4 Plus from
Michelin are also supposed to be pretty good.
There is something I do not understand though. Switching to a lower
rolling resistance tire is supposed to improve mpg by just a few
numbers. So assuming that "few" is three and the original mpg was 25
the improvement is 12%. Which also means a 12% improvement of range.
Well, not according to evconvert.com's calculator. With 0.015 rolling
resistance (a pretty average number) I get 30 miles of range at 40
miles per hour. Now I switch to a tire rolling resistance of 0.010.
Now I get a range of 42 miles at 40 mph. That's a 40% increase!!!
That's completely off!!!
On 7/10/07, Phil Marino <[EMAIL PROTECTED]> wrote:
Tom
Unless a car has dragging brakes or faulty wheel bearings, tire drag
dominates the car's rolling resistance.
That drag depends on the particular tires, and the tire pressure, and the
total vehicle weight. Since tire drag is proportional to the load on each
tire, it doesn't matter how many tires you have, or how the weight is
distributed.
The next obvious question is : what brand, size, and model are your tires (
front and rear) ?
If you don't know, you can easily get this information from the sidewall of
the tires.
Being able to push it with one hand doesn't tell us much. If you couldn't
push it with one hand, it would there was a problem somewhere.
Phil Marino
>From: "Tom S." <[EMAIL PROTECTED]>
>Reply-To: ev@listproc.sjsu.edu
>To: ev@listproc.sjsu.edu
>Subject: RE: conversion question
>Date: Tue, 10 Jul 2007 19:00:41 -0400 (EDT)
>
>Hi Rodger,
>
>I disagree. I can push my car easily with one hand of a level street, I
>don`t think you can do that with a standard car. I`ve been testing this
>car for years,and could make many claims, however without an official it
>wood be meaningless, so i`ll just stick to the facts about the car.OK
>
>Tom Sines
>
_________________________________________________________________
http://liveearth.msn.com
--- End Message ---
--- Begin Message ---
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* ---REMAINDER OF MESSAGE TRUNCATED--- *
* This post contains a forbidden message format *
* (such as an attached file, a v-card, HTML formatting) *
* Lists at sjsu.edu only accept PLAIN TEXT *
* If your postings display this message your mail program *
* is not set to send PLAIN TEXT ONLY and needs adjusting *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
--- End Message ---
--- Begin Message ---
Thanks for the detailed replies guys.
Mark, I was thinking about just changing the gears on the differential
box and keeping the standard transmission stock. It should put me into
that sweet spot for motor RPM. Also, I'm fully allowed to use the
school's facilities, including the CNC machines and the ProE licenses.
The students are also willing to help, and they'll be the ones
physically doing the conversion. I'm just the designer and researcher.
The problem is that I'm quite certain that most people won't have
access to 4 axis CNC milling machines with $20 000 software licenses.
I'm trying to make a project which is simple and reproducible under
normal circumstances but at the same time, still giving acceptable
performance and remaining economically viable. Ideally, this car
should be able to be used anywhere in the city and pay itself off
within 'x' number of years.
Then I'm going to document everything and put it all online for people
to copy/learn from. I've already started a work log.
The reason that I'm trying to avoid the machine shop whenever possible
is because I'm going to consider any machine shop use as "outsourced"
and will add it to the bill of "cost". In reality, this won't cost us
anything except for a few hours by students. However, if someone else
were to reproduce this project, it would, most likely, cost them
money, so for all intents and purposes, it "cost" us money too.
Peter, it's good to hear that the zilla 1k is the ideal controller.
What is the % efficiency on these units anyways?
So other than these things... I think I may be set to determine a
preliminary price, and a preliminary cost/benefit calculation! I'll
get back to you guys with the numbers soon. I can't properly estimate
the cost of the transmission or the shocks yet though.
--- End Message ---
--- Begin Message ---
>> I disagree. I can push my car easily with one hand of a level
>> street, I don`t think you can do that with a standard car.
I just pushed my '81 300SD with one hand earlier today - certainly not a very
*quantitative* measurement of what it takes to move an old luxury diesel. You
probably haven't read the list before or you'd have remembered numerous posts
on this - the most thorough converters minimize rolling resistance to the point
of taking a "lady's gloved finger" to move a lead sled!
--- End Message ---
--- Begin Message ---
I just realized that I completely forgot to sign my last email. Oops.
I've come across a funny occurrence when playing with Uve's
calculator. It seems that I get the best mileage at first gear, 10mph
no matter what I set the gears at! Does this make sense? I know this
is the "lowest torque" situation, but the motor efficiency curves
don't seem to indicate that. When driving, should I just be waiting
till I hit the motor RPM limit before shifting to the next gear? Isn't
there a point when the motor just doesn't get the best mileage at
first gear?
Matt
--- End Message ---
--- Begin Message ---
It's because any tinfoil or mylar-surfaced item forms a "radiant barrier".
Radiant barriers are very effective are reflecting infrared heat,
however this is only one of the 3 methods of heat transfers- IR
radiation, convection, and conduction.
The RB thing works great in attics where radiation is a large factor.
Other scenarios may see less dramatic results however. The industry
accepts these high stated values in their specifications only for a
specific scenario (usually attic).
Danny
Alan Brinkman wrote:
Tehben,
The R value of 14.5 seems quite high for quarter inch foam. At the
bottom of the web site they mention that the R value depends upon air
space and the heat conductivity of surrounding materials. Polyethylene
foam is about R 3 per inch so 1/4 inch is R 0.75 They are relying upon
air space and surrounding material to get their R value.
Alan Brinkman
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Tehben Dean
Sent: Tuesday, July 10, 2007 6:12 PM
To: ev@listproc.sjsu.edu
Subject: Re: Battery Boxes and Heating
Has anyone used Prodex Total Insulation? foil-foam-foil 14.5 R Value
http://www.insulation4less.com/prodex_Ffmf.asp
--- End Message ---
--- Begin Message ---
I keep wondering... since Congress recently finally showed an interest
in increasing mpg standards, and tires do affect mpg, you'd think they'd
at least require that tire mfgs make rolling resistance data available.
That might be a step forward at least. Be nice if the mfgs could get
into a war over who can make the most efficient tire.
I've heard lots of complaints that the tire supply is somewhat volatile
though. I remember years ago where a guy working at a tire place first
looked over his shoulder and mentioned that one of the brands lost
several pounds of weight each even though it was still the same name
brand, model, size, and ratings. Something changed quietly. Just
wondering if RR data from last year's tires might not be the same as RR
from this year's tires even with the same brand, model, size, and rating
and should be identical. Data not specified by the mfg can be changed
at will without violating any official expectations.
Danny
Joseph T. wrote:
Rolling Resistance numbers on tires is tough to find. I've heard that
Consumer Reports rates them, but I'm not sure. I myself did alot of
research on this and found only one article giving some good numbers
on rolling resistance.
http://www.greenseal.org/resources/reports/CGR_tire_rollingresistance.pdf
Someone please tell us of other places where rolling resistance
numbers are published.
My consensus is that if you want to go for the outright lowest rolling
resistance, go for the B381 from Bridgestone. It's got the lowest
resistance score (which is good) These tires used to be used on the
old Honda Civic Hybrid. They're not used anymore, and I've heard that
the grip isn't so good.
The HTR 200 from Sumitomo is supposed to have great grip, while still
keeping a pretty decent rolling resistance number. The MXV4 Plus from
Michelin are also supposed to be pretty good.
There is something I do not understand though. Switching to a lower
rolling resistance tire is supposed to improve mpg by just a few
numbers. So assuming that "few" is three and the original mpg was 25
the improvement is 12%. Which also means a 12% improvement of range.
Well, not according to evconvert.com's calculator. With 0.015 rolling
resistance (a pretty average number) I get 30 miles of range at 40
miles per hour. Now I switch to a tire rolling resistance of 0.010.
Now I get a range of 42 miles at 40 mph. That's a 40% increase!!!
That's completely off!!!
On 7/10/07, Phil Marino <[EMAIL PROTECTED]> wrote:
Tom
Unless a car has dragging brakes or faulty wheel bearings, tire drag
dominates the car's rolling resistance.
That drag depends on the particular tires, and the tire pressure, and
the
total vehicle weight. Since tire drag is proportional to the load on
each
tire, it doesn't matter how many tires you have, or how the weight is
distributed.
The next obvious question is : what brand, size, and model are your
tires (
front and rear) ?
If you don't know, you can easily get this information from the
sidewall of
the tires.
Being able to push it with one hand doesn't tell us much. If you
couldn't
push it with one hand, it would there was a problem somewhere.
Phil Marino
>From: "Tom S." <[EMAIL PROTECTED]>
>Reply-To: ev@listproc.sjsu.edu
>To: ev@listproc.sjsu.edu
>Subject: RE: conversion question
>Date: Tue, 10 Jul 2007 19:00:41 -0400 (EDT)
>
>Hi Rodger,
>
>I disagree. I can push my car easily with one hand of a level street, I
>don`t think you can do that with a standard car. I`ve been testing
this
>car for years,and could make many claims, however without an
official it
>wood be meaningless, so i`ll just stick to the facts about the car.OK
>
>Tom Sines
>
_________________________________________________________________
http://liveearth.msn.com
--- End Message ---
