# Looking For 50 Mile + Success Stories



## paker (Jun 20, 2008)

I can't remember reading anyone in the EV album that drove highway speeds, as in interstate highway, on a regular basis, which is something I would need when I build mine. I have a 36 mile round trip to and from work at an average of 65 mph. Anyone here do that?


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## Rook (Jun 5, 2008)

It doesn't have to be highway speeds. Just fast enough to not be a hazard and not be too late for work.


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## madderscience (Jun 28, 2008)

It is possible. I have a 1985 toyota MR2 EV conversion that has been operational since September 2007. In a recent Seattle Electric Vehicle Association "Range Rally" I did 66 miles on one charge. 56 of those miles were on interstate 5 in washington state, including several moderate hills. The batteries were at the lowest safe discharge level when I was done so I would not normally want to go 66 miles, but 50 might be OK if you kept a close eye on battery balance and condition, etc. I drove at 55mph on the highway. Had I been doing 65, I might have only gotten 40 or 45 miles.

The trick to get that kind of range is pretty simple: Small, light, aerodynamic car and a big battery. The best (common) conversion candidates IMHO are the 1990's geo metro, the 1985-1989 Toyota MR2, and an 89 to 91 honda crx or civic hatchback. As for battery, I have 21 trojan T-105 golf cart batteries, weighing about 1250lbs in my car, which had an original curb weight of about 2300lbs, but as an EV weighs about 3400.

BTW the "winning" car in the range rally was a geo metro with 1700lbs of batteries, which did 101 (yes, 101) miles on a similar route at 55mph. In addition to the larger battery pack than mine, his batteries were heated to 120 degrees which is another trick to increase energy capacity, though heating them on a regular basis to that extreme will shorten their lives, though it is a very good idea to insulate them especially if you live in a cool climate.


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## Rook (Jun 5, 2008)

Congratulations on doing 66 miles in the range rally! I used to live in Seattle many years ago so I will also say congratulations for driving on I-5 at all. 

When I lived there I remember having several manual transmission adventures on Seattle’s hills. I also remember sitting on the bus while stopped on Queen Ann Hill and smiling to myself as I watched old ladies climbing the bus interior to get to the door. It seems that Seattle isn’t the friendliest place for EVs.

Is your MR2 on the EV Album? I’d love to see more details of what you’ve done.

Thanks for the reply


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## madderscience (Jun 28, 2008)

Hi Rook-

This is my car:

http://www.evalbum.com/1244
http://www.amphibike.org/index.cgi?page=pages/3_wheels/mr2

Seattle does have its share of hills, and though my car is torquey enough to handle them (It has an advanced DC 9" motor in a car many converters would have put an 8" into) I try to find flatter routes when possible as that keeps the range higher. 

For what its worth, seattle also has one of the most active EV organizations in the USA outside of southern California. (http://www.seattleeva.org) At a recent local car show, we had 27 EVs in attendance, of which probably 20 were homebuilt conversion and the balance factory built or commercially converted EVs.

-Brian


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## Rook (Jun 5, 2008)

I still love Seattle.

Your MR2 looks great! I am impressed. I’ve been looking around for a Honda Civic and never considered an MR2. And I must say that the MR2 just has more cool about it than the Civic. I took a quick look on Auto Trader the closest 1985 MR2 is 888 miles from my house.

I also learned some from your web site. I didn’t know it was possible to have springs custom made. At least not at any kind of reasonable price. Obviously you can have anything made if you want to pay enough.

I’m still in the planning stage, but when I get a little farther along it is suspension that I will need the most help with. I know my electrical circuit and most of the other mechanical parts are fairly straightforward. But suspension and especially custom suspension is something I will have to learn.


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## madderscience (Jun 28, 2008)

Thanks for the compliment.

For something like an older toyota MR2, your best bet in finding one is probably craigslist or local newspaper classifieds. For a decent body but non-runner, you should be under $1000. For a runner with a decent body, maybe $1500 to $3000 for a really nice one. At least, that is what the going prices are around seattle. Mine was a non runner, and the body was a bit banged up but no rust (a big plus for me) and I paid $400 for it.

Other similar cars are the pontiac fiero, which is a common conversion, but it is both heavier and less aero than the MR2. There is also the fairly rare and considerably older fiat X1/9, but I know very little about them except they are a similar mid engine, rear drive sports car configuration.

As for the springs, that was relatively easy though it took a few weeks. I went to a custom spring shop (any big city should have a couple) with one each front and back original springs, and said "I need two each like this, with 200lbs more capacity per coil" and they made them. The upgraded shock absorbers are just performance strut inserts which can be ordered online, and everything else is stock. 

-Brian


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## JSRacer (Jun 22, 2008)

Soon I will decide on a voltage system and package for my 1993 Eagle Summit. I've gotten some quotes from EV-America and one is with an Advanced 8" motor and the other is with the 9" Advanced motor. There's only $200 difference between the two. Which will give better range, and why?


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## madderscience (Jun 28, 2008)

Hi JsRacer-

Sort of like with gas engines, the bigger motors have higher torque, but lower maximum RPMS. This makes sense when you think about it becuase the magnetic fields have a longer lever arm with which to exert force on the motor shaft in a larger diameter motor, so you get more torque. But also, due to the larger diameter armature and commutator (the spinning parts) the centrifugal forces build faster and thus the maximum RPM is less. This isn't all there is to it by a longshot, but its a good 30-second description.

The upside of a higher torque constant (the amount of torque you get for a certain amount of current (amps) flowing through the motor) is less amps for the same amount of torque. less amps will reduce overall stress on your batteries and motor controller. (The higher voltages needed to spin the 9" motor at the same speed as an 8" are less stressful on the system than high current (amps) is.

As for efficiency Any series wound DC motor should have a curve chart that looks something like this: (pdf) though you might not be able to find published info for every motor out there. 

http://www.evparts.com/img/mt2120torquecurvefancooled.PDF

All else being equal between motors you are considering, look at the efficiency curve. The flatter, and higher the better. In the case of this curve which is for the advanced DC 9", the efficiency peaks at almost 90%. The advanced DC 8" is slightly less efficient than this, and the torque curve drops off slightly more on either end of the curve (high RPM and high torque)

So in my opinion, (at least partly based on facts) between the two motor choices you specified, I'd go with the 9". Of course, physical considerations like clearance for installing the motor may necessitate a smaller motor but probably not in your case. Good Luck.

One more thought: Assuming you are planning a freeway capable vehicle, don't build it with less than a 120v battery.


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## Rook (Jun 5, 2008)

I started this thread talking about range and was thinking about it today and it generated another question. How does an EV range rally work? It seems to me that with a gas-guzzler there is a gas tank and if you have a range rally and make an error someone looks at you as if you’re an idiot and brings you a gallon of gas. But with an EV, if you make a mistake what happens? Does someone bring you an extension cord?


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## madderscience (Jun 28, 2008)

The whole point of a range rally of course is to see how far you can go in your EV on one charge. The nice thing about doing that sort of thing in a rally/competition setting is that if you do run out of charge you have lots of friendly EVers out there to come rescue you with a tow strap, generator, or whatever.

The rules vary, but for the May 2008 SEVA rally there were three classes, one for the farthest distance (at least 80% freeway miles) for a lead-acid powered car, one for farthest distance (at least 80% freeway miles) for any battery chemistry, and one for farthest distance driven by an NEV.

This is the link to the wiki page for the rally I participated in, and also the results.

http://www.seattleeva.org/wiki/EVents_2008_05_10


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## e-porsche (Jun 13, 2008)

madderscience said:


> The batteries were at the lowest safe discharge level when I was done so I would not normally want to go 66 miles, but 50 might be OK if you kept a close eye on battery balance and condition, etc. I drove at 55mph on the highway. Had I been doing 65, I might have only gotten 40 or 45 miles.


madderscience, 

That MR-2 is an excellent choice for battery space. I'm trying to establish a reality based range estimation on my own project and your information has provided an excellent reference point. One further question: in your normal driving, what would be your range at around 50% depth of discharge at 55mph?

Thank you,

Steve


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## 92 Escort EV (Jul 3, 2008)

Rook,

I converted a 1992 Ford Escort wagon, and have been driving 47.7 miles each day for about two weeks now. The Curtis State of Charge meter has not gone to the last "amber" indicator, except two times. These times were either due to my driving being too agressive, or the fact that I let the car sit unused all weekend. On that monday I felt that I took the batteries lower than I would like on a regular basis, but did make it home just fine at 30 MPH, with the SOC going to the last red indicator the final few yards home. 

See my car at:
http://www.evalbum.com/1818


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## madderscience (Jun 28, 2008)

Hi E-Porsche-

In my car a 50% DOD is around 30 miles for my usual driving habits which is not very aggressive, but often including some hills. If it were a constant 55mph, level, no wind, etc. It would probably go about 40 miles to 50% DOD. I got to 66 miles at 80% DOD (by specific gravity measurement on my known weakest cell) in the range rally by not starting and stopping nearly so much as usual. (I stopped twice to check specific gravity, otherwise it was all continuous driving except the last 10 miles on surface streets)

The MR2 can hold a lot of batteries, but I did have to do quite a bit of sheet metal mods to do it and preserve some trunk space. Lotsa details on my website (url earlier in this thread). However others have put 15-18 of the same form factor of batteries as mine (Trojan T-105s) in an MR2 without such mods by taking the entire trunk for batteries.

Hi Brian (92 Escort EV)-

Pump those tires up to 50!. If you are mostly driving at lower speeds there should be very little risk in overinflating by 20%. I am running 55psi in my 44psi-rated bridgestone B381's, but I live in a considerably cooler climate area than you do. Also, you might consider getting an alignment job now that the car is weighted down. Also make sure the cars brakes don't drag, even slightly. Doing all that might buy you a few percent better efficiency and keep those battery cycles a bit shallower.


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## Rook (Jun 5, 2008)

92 Escort EV,

Thank for showing your EV. I wouldn’t have thought a 92 escort would get that type or range, but you did it. I like your rear battery box. It looks, well, like a car.

I started this thread because, like you, I have a 24 mile drive to work and no ability to charge while I’m there. In studying EV conversion I was starting to think that the technology or at least affordable technology hasn’t progressed far enough for my commute. I’m sitting here right now listening to a commercial on the radio for the Chevy Volt, and how the best minds are working on batteries to allow it to go 40 miles on a charge. Come on GM, you can do better. 

Do you expect a shorter battery life if you bring your batteries to 70% DoD every day? I’d also be curious what you did to beef up the suspension on the Escort.

Thank,
Larry


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## 92 Escort EV (Jul 3, 2008)

I checked my specific gravity after driving to and from work, (about 48 miles, see posts above), and found that I am at about 55% DOD based on my lowest cell. Hopefully this won't shorten the life of the battery pack too much. My biggest problem is the few months that are 100-110+ degrees here in the Phoenix AZ area.

The suspension was already upgraded by the engineering students at the University of California, Irvine (UCI) for the 1995 Hybrid challenge. See how it looked when I got it here http://www.evalbum.com/678 . It was not working when I got it, but had many usefull parts, and also upgraded 4 wheel disk brakes. Basically they added gas struts (shocks) and beefy springs. The springs have a larger diameter cross section and MANY more coils. I did find this site for springs - http://www.coilsprings.com/index.html

I agree with you that the GM-Volt should be able to do better than 40 miles, but it is still moving the weight of the "engine" it has to charge the batteries. If you look up the old Toyota Rav-4's that were EV's direct from Toyota, you will see that many are still on the road with original batteries going 100+ miles per charge. Some have well over 100K miles on them.


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## madderscience (Jun 28, 2008)

55% DOD after 48 miles is darn good, actually. The high temperatures are helping this. In the range rally I participated in the winner heated his batteries to 120 degrees farenheit. Mine were at ambient temperature plus whatever heat gain from the operation of the car. but exceeding 120 degrees is risking battery damage from plate warping and also high heat will accelerate chemical deterioration of the plates so for an arizona car perhaps keeping the batteries cool is a bigger issue than keeping them warm, which is the problem I worry about more up here in seattle.

A lot of EVers with lead acid try to keep their discharges at 50% or less though the manufacturers say you can go to 80% so you probably aren't in bad shape.


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## Rook (Jun 5, 2008)

92 Escort EV,

Thanks for the web site on coil springs. Living in Florida within searching distance of Altamonte Spring, Tarpon Springs, Bonita Springs, Silver Springs, etc. It’s hard to do an Internet search for a company that builds coil springs.


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## Rook (Jun 5, 2008)

This thread has lead me to the conclusion that a range of 50 miles is at the upper end of what Lead Acid Technology is going to give us. There are a few genius people that are able under the right conditions to go farther, but for the daily commute or the carefree drive 50 is at the right end of the bell curve. For me with the 60 miles I have to drive many days it means that it wouldn’t be cost effective to build a lead based EV. I couldn’t use if for the drives that cost the most money. Unfortunately other technologies are prohibitively expensive. 

But that doesn’t lessen my desire. It means that I have to slow down, plan carefully and watch to see if I can find a design that will work in my situation. Actually that’s a good thing. I’m about to start a remodeling project where half my house will be demolished. My wife has been living in fear that I’ll have two large projects going and either won’t finish either or worse (for her) will only finish the car. While I’m working on the house I’ll be learning more about EVs and watching battery technology. Hopefully during that time the cost of Lion batteries will fall as they are put in more and more hybrids and hopefully pretty soon plug in hybrids.


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## JSRacer (Jun 22, 2008)

What do you guys think we'll see in 2 or 3 years in battery tech? Think our current set-ups will achieve 100 miles range or better just with better batteries?


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## ga2500ev (Apr 20, 2008)

Rook,

What you've stated is probably true of your standard lightweight sedan that's filled with lead acid up to its GVWR. But I don't think that it's in fact the top end of the technology. The Red Beastie is a clear counterexample:

http://www.evalbum.com/037

They simply designed for long range travel. But it's 2.5 tons, of which most is batteries. Let's estimate the Wh/mile rating of RB. I'm a bit concerned about the numbers I'm getting. Generally with Lead Acid the usable power out of the pack, accounting for 80% DOD and Peukert is 44% of the pack total. The RB used 40 T-105 which has 1350 Wh of energy each giving a total of 54 kWh for the pack. 44% of that is 23960 Wh.

Now with 120 mile range it shows a Wh/mile of 198. That just seems real low for a heavily loaded pickup truck, even if you do the aerodynamic and other efficiency work.

It just seems to me though that a midsized pickup with 36 or so lead acid batteries should be able to pretty comfortably get in the range near 100 miles per charge. Also the Peukerts go down as the volts go up.

So let's try a thought experiment and use 350 Wh/mile as a reasonable number. Say you get your hands on a Warp-9 and throw it in a midsized pickup. The power it with a 168V string of 12V batteries (say 125 Ah each). Because of the higher voltage the amp draw will be down and therefore peukert will not have as much of an effect. So say that we can draw 55% of the total pack energy instead of 44%.

Now 12V*125Ah = 1500 Wh * 14 batteries = 21 kWh.

Now that won't get you there. At 350 Wh/mile and taking 55% of the pack energy.

21000 Wh * .55 = 11550 Wh
11550 Wh/350 Wh/mile = 33 miles.

So now double up the string and carry 28 batteries. We're now talking 66 miles of range. And it only weighs 1600 lbs, which a pickup would have no problem with.

Finally if you really needed to extend the range, I'm still curious about the utility of a battery trailer. You'd only need to carry 14 batteries and it would weigh a bit more than 800 lbs along with the weight of the trailer. But adding another 30+ miles of range would get you near 100 total miles for the slight inconvenience of hooking up a trailer. And you'd only need to do it every once in a while.

Just a thought.

ga2500ev


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## Rook (Jun 5, 2008)

I’ve been studying EV conversion for about six months. My studies have swung me between hope and despair numerous times. The Red Beastie was a moment of hope. That was until I took a closer look. Then I realize that the Beastie was carrying 2,480 pounds of batteries. It’s payload capacity was only 1580 lbs so the truck was carrying half a ton more than its design weight and that seemed scary. Like you pointed out the numbers didn’t seem to add up for range. That plus the fact that neither the truck nor its builder are around anymore made me wonder it the Red Beastie is legendary or legend? I’ve seen numerous posting pointing to the Red Beastie as the icon of range and power, but I wonder if it worked so well why it hasn’t been copied? By now there should be a Green Beastie, a Blue Beasie, a Chartreuse Beastie…

I’ve wondered about the trailer idea too. You’d still be carrying as much weight and it would still drag you down, but at least you wouldn’t worry about breaking the frame in half the first time you hit a bump.


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## Rook (Jun 5, 2008)

JSRacer,
There is no question that the current setup of DC motor and controller will support a 100 mile range vehicle. The sad part is that the technology already exists. Lithium Ion batteries would do it today. Further I believe that there is magic number at that 100 mile range number. I think that an EV that can travel 100 miles on a charge would be widely accepted. A vehicle with less than 50 miles of range will take too much trip planning for the average driver. We need 100 mile vehicles in order for the revolution to happen.

At the same time I don’t see the cost of Lion batteries falling any time soon. It’s simple supply and demand. There is a huge demand right now. Lion batteries are in every cell phone, every iPod, every laptop, and many cordless tools. I read recently that the limiting factor in hybrid production is the number of batteries they can make. I think that for the EV community it gets worse because I think, although I don’t have any data, that the profit margin on small batteries is higher than the large capacity units. I’m guessing that there isn’t an incentive to make marine or golf cart size Lion batteries. There might be for wheel chairs, but that’s medical and who can afford it? I really hope I’m wrong, but its not looking good so far.


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## avn-tech (Jun 16, 2008)

ga2500ev,

I like your idea of a trailer. With a trailer you could add additional braking (saftety factor), and help take load off the prime mover frame.

I have been thinking of using a small generator to extend my range. I have a 65 mi (downhill) commute to work. I can then recharge at work, but have a 65 mi uphill commute home. 

I think I can build a truck to go 65 mi to work. But going home, uphill the car will think it is going 100 mi. If the generator can give me the extra 10-20% necessary to get home, I can use it for my commute. If that does not work, I will use the truck around town and still save on fuel cost.

As an alternate I also considered a trailer.


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## Bowser330 (Jun 15, 2008)

I have seen an owner EV-album that has a small generator that gives the oner 80mile per charge. I think normally he gets the standard 40 mile range (without gen).

There is a miata on Evalbum that isnt finished yet, but with 15K$ worth of lithium iron phosphate cells is proposed to get 90-100 mile per charge...

He also has a Warp-11 motor which will really fast in the lightweight setup...


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## Telco (Jun 28, 2008)

I don't think you guys are giving the generator enough thought. With a charge controller, when the average person stops to go into a store, the generator can be running max out to recharge the batteries. Range would be unlimited for the average person doing daily chores. Out on the open highway is where you'd start running into problems, unless the genset were large enough to recharge the batteries while running the vehicle. Proper control electronics is what is needed to control the generator when needed. Even long distance doesn't have to be a problem, so long as the driver understands that he needs to stop every so often to eat or take a break from driving while the generator puts the charge back on.


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