Electric Vehicle Discussion List
Tue, 10 Jul 2007 22:47:38 -0700
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
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--- 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
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--- 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.
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--- 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] [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
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--- 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.
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--- 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 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
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--- 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] [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
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--- 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
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--- Begin Message ---TomUnless 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 MarinoFrom: "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.OKTom Sines_________________________________________________________________ http://liveearth.msn.com
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--- 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] [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
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--- Begin Message ---"This car has lots of potential" :-)
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--- 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 > >
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--- 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 > >
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--- 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
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--- 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
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--- 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 capacityDan
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--- 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
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--- 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
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--- 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.
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--- 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!
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--- 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
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--- 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] [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
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--- 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 eachtire, 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 ofthe tires.Being able to push it with one hand doesn't tell us much. If you couldn'tpush 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
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