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Electric Vehicle Pros & Cons

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  • rorrrorr Member Posts: 3,630
    "Why would a buyer narrowly define his "needs" when there are existing choices that will surpass those requirements at lower cost?"

    He won't. Which is one reason I stated a long ways back (although not lately I admit) that EV's won't gain wide acceptance unless the cost of gas is too high.
  • daysailerdaysailer Member Posts: 720
    differences in conversion efficiency are, at best, on the order of 3/1 while energy densities are orders of magnitude different - it is not misleading. You can't get there from here! That 36kwh as gasoline weighs but 6-7 lb!
  • midnightcowboymidnightcowboy Member Posts: 1,978
    LOL, I remember the day in Kindergarten, when my nap partner tried to describe to me Albert Einstein's Theory of Relativity. While he attempted to make sense, he just didn't have the experience and knowlege in science and engineering to understand waht he was saying, so he ad libbed. Even at that young age he was not plausible.

    There is so much involved in EV technoplogy and so much we still need to learn and research. Think of EV as being at the vacuum tube stage of computer development. Some of the explanation and knowledge is not known yet and will be invented by our children and their children. So trying to explain the unknown is sometimes not credible.

    To the future of EV,

    MidCow
  • daysailerdaysailer Member Posts: 720
    What wonders may be discovered in the future are not the subject - those are unknown and, as you say, do not make for credible discussion.

    But the limiting factors of present technology ARE known and it is pointless to posit an EV that is beyond those limits. THAT is not a credible discussion.
  • snakeweaselsnakeweasel Member Posts: 19,592
    But the limiting factors of present technology ARE known and it is pointless to posit an EV that is beyond those limits. THAT is not a credible discussion.

    I would say that as long as whats posted is within feesability it is credible to discuss whats beyond current limits. Face it, technology increases and extends the current limits of just about everything.

    2011 Hyundai Sonata, 2014 BMW 428i convertible, 2015 Honda CTX700D

  • tpetpe Member Posts: 2,342
    differences in conversion efficiency are, at best, on the order of 3/1 while energy densities are orders of magnitude different - it is not misleading. You can't get there from here! That 36kwh as gasoline weighs but 6-7 lb!

    I agree with part of that. The best batteries weigh about 100x more than gasoline per kWh stored energy. However, even though I cited this figure I think the 3/1 conversion efficiency is being a little generous towards the ICE. The RAV4 EV had a 27 kWh battery pack, the energy equivalent of 3/4 a gallon of gas. The RAV4 EV weighed about 500 lbs more than its ICE counterpart yet had almost identical performance. Now lets do a test. See how far the RAV4 EV can go on a full charge compared to how far the ICE version can go on 3/4 a gallon of gas. My guess is that the difference in distance will be more than 3 to 1. Now is the RAV4 EV driver going to be all that upset that his energy weighed 100x more?
  • daysailerdaysailer Member Posts: 720
    Taking your figures at face value, you are ignoring the additional 500lb and its effect on handling as well as how much less range the EV version has IN SPITE OF its 500 additional lbm.

    But to my original point, the EV version does not come close to parity with the ICE in spite of its high price. How much would the EV weigh if it provided the range of the ICE?
  • tpetpe Member Posts: 2,342
    First off, since when do SUV buyers care all that much about extra weight and the handling consequences? If anything one of the reasons SUV buyers purchase these vehicles is for the extra weight. The RAV4 EV spread its battery pack below the cabin creating a lower center of gravity. My understanding is that it slightly improved handling. The RAV4 EV also had NiMH batteries. The increased energy density of Li-ion batteries would have made it about 300 lbs lighter or only 200 lbs heavier than its ICE counterpart. If the EV had a range comparable to the ICE it would weigh a lot more, maybe 1500 lbs. If it had a range of around 80 miles it would actually weigh less. While the batteries do weigh more than gasoline the electric motors weigh less and there are several other rather heavy components that you can dispense with on an EV.

    When you say that an EV doesn't come close to parity with an ICE you need to be more specific. Parity in what regard? Range? No. Performance? Yes. Pollution? No. Efficiency? No. Initial cost? No. Routine maintenance? No.

    You are really comparing apples to oranges. And to a previous point you made regarding people being unwilling to purchase a vehicle if there is another that meets the same needs at a lower cost. That statement is only true if the decision as to what vehicle to purchase was based solely on rational and practical considerations. That is just not the case. Take a look at the cars you see on the road and ask yourself, could that driver have achieved the same or greater utility at a lower cost? In a good percentage of the cases the answer would be yes. There are definitely personal and emotional factors at work in the car buying process.
  • apeweekapeweek Member Posts: 133
    The little ZAPs, TWIKEs, ZENNs, and other NEVs have never appealed to me much. Until a serious EV at an affordable price comes along (I'm hopeful for this Chinese import: http://www.milesautomotive.com/products_xs200.html ), The EVs I prefer to drive are conversions. Some examples here:

    http://grassrootsev.com/convert.htm

    The downside is driving around an old car body, and putting up with old lead-acid battery technology. But the price is at least affordable, I get all the economic advantages of EVs (low fuel and maintenance costs) along with decent performance (acceptable acceleration and handling, and freeway speed capability.)

    The short range is not really a hindrance for commuting, since I can charge at work.
  • tpetpe Member Posts: 2,342
    A question. These EV conversions like yours and others I've heard about. Do they typically take advantage of regenerative braking?

    I think that there is a very good chance that EVs will be the way that the Chinese break into the auto market. With their ability to manufacture at low prices we may see some very attractive offerings.
  • gagricegagrice Member Posts: 31,450
    It was not doomed because of the charging stations. That was just a miscalculation by a lot of folks thinking that CA would stick by their mandate. I am only familiar with the ones at Costco. They cost them a lot of money that did not get reimbursed. I think it was mostly a way to get in on the Clinton alternate fuel money handout. GM got the money and the technology. We did get NiMH battery technology from the fiasco. We paid for it though.
  • gagricegagrice Member Posts: 31,450
    I agree with your assessment of that Zap EV's appearance. It perpetuates a negative stereotype.

    No uglier than a Prius, xB or Element and they have plenty of folks interested.
  • tpetpe Member Posts: 2,342
    I agree that those vehicles are also ugly but they don't have the glorified golf cart stigma to overcome. Actually I wonder if the Prius was intentionally made ugly to keep its popularity in check. I think the designers were the same people that got fired by Pontiac for designing the Aztec.
  • gagricegagrice Member Posts: 31,450
    After reading more on the Xebra it is not being imported as a car. It is an enclosed 3 wheel motorcycle. I think that gets them around a lot of safety issues. Personally I would like the PU model as it would just be for the wife and I to go shopping. I am seriously considering a dealership for San Diego, if someone else does not beat me to it. I wonder if the Chinese will keep up with demand. That price is less than many golf carts being sold that cannot be licensed.

    And yes it is kinda ugly but so are most of the new cars out there today. I think ugly is in right now.
  • apeweekapeweek Member Posts: 133
    ...Do they typically take advantage of regenerative braking?

    You're less apt to find regen braking in a conversion. It's difficult to implement.
  • gagricegagrice Member Posts: 31,450
    From what I can read between the lines, regen braking is more of a selling point than a real gain in mileage. From my experience with both the GMC Hybrid and several non hybrid GM PU trucks the gain with auto stop and regen braking is nearly worthless from a gas mileage standpoint. It would be interesting to see how much actual power you get back from regen braking in normal level deceleration. Going down hill I imagine would give you a bit of a boost. Just something more to go bad and cost an arm and a leg to fix after the warranty is up. Is regen braking covered in the hybrid warranty?
  • terry92270terry92270 Member Posts: 1,247
    It does quite a bit more than whatever source you are using said.

    And yes, I beleive the regen system, not the pads, are covered under the longer warranty.....
  • tpetpe Member Posts: 2,342
    Regenerative braking is the primary method that hybrids use to achieve greater mileage, especially in the city where there is a lot of stop and go. It really doesn't add much to the complexity of an EV because an electric motor is already basically a generator. In fact this is also why you rarely need to replace your brakes in a car with this regenerative capability. It is one of the few areas where a significant benefit can be achieve without adding a lot of complexity or additional devices.
  • midnightcowboymidnightcowboy Member Posts: 1,978
    Where does the additional 500 lbs come from? You have to take the net weight. No gas -1oolbs, no transmission -200lbs, No ICE -200lbs, + elctric motor 50 lbs + batteries +500 lbs, net maybe 50lbs extra.

    It is like saying that gas has 3 times the power of batteries dooesn't make sense. People are making speciualtions about items that don't directly compare. If you have a 20 gallon gas tank and you have a range of 400 miles . How does that compare to a 500 lb battery and electric motor that has a 200 mile range ? It doesn't

    ROTFLMAO,

    Thanks for the humor.

    MidCow
  • daysailerdaysailer Member Posts: 720
    The 500lb comes from figures in an earlier post to which I responded.

    But EV's have all carried an onerous weight penalty whether an amateur conversion or a ground-up Ev design. Differences in drivetrain mass for a given power/mass are small as compared to the difference in mass between a gasoline fuel system vs batteries of (yes, even after adjusting for differences in drive efficiency).

    The fact that there has not been an EV produced that is comparable to ICE vehicles IS the point!! And there will not be until a magical battery technology is invented.
  • tpetpe Member Posts: 2,342
    The 500 lbs was simply a statement of fact based on published specs for the RAV4 EV and the traditional ICE version of the RAV4. I also posted that this vehicle used a 900 lb NiMH battery pack. Using Li-ion chemistry this same amount of energy could have been stored in closer to a 500 lb battery pack.

    But EV's have all carried an onerous weight penalty whether an amateur conversion or a ground-up Ev design


    ICEs have always carried an onerous weight penalty compared to electric motors. ICEs have always carried an onerous torque penalty compared to electric motors. ICEs have always carried an onerous required maintenance penalty when compared to electric motors. Etc., etc., etc.. I'm not sure why you are so fixated on battery weight. Obviously extra weight is a negative factor when it comes to handling, performance and fuel efficiency but if the other characteristics of an EV can more than offset this who cares? The Tesla Roadster weighs 600 lbs more than the Lotus Elise that it is based upon. It handily outperforms the Elise and uses a lot less energy in doing so. The problem is not this elusive, magical battery technology it is battery price.
  • daysailerdaysailer Member Posts: 720
    ..."I'm not sure why you are so fixated on battery weight."

    because the inadeqate energy and power density of batteries is THE technical obstacle to a practical EV! Price, as you note, is the economic obstacle.

    Present electric drive technology could produce a wonderful vehicle if it only had a practical power source. It doesn't!!!!!
  • tpetpe Member Posts: 2,342
    Present electric drive technology could produce a wonderful vehicle if it only had a practical power source. It doesn't!!!!!

    Practical for what? Before determining whether or not a vehicle is practical you have to identify how it will be used. A Toyota Corolla is a very practical vehicle but not if you plan on towing a boat. The point that a lot of us are making is that an EV is already practical for our typical use. Certainly not for everyone but for enough of us that a market exists at the right price. For some reason you seem to think that the power density of the fuel source is a major priority for car shoppers. Look around. Does it appear to you that people care all that much about what their vehicle weighs?
  • gagricegagrice Member Posts: 31,450
    you have to identify how it will be used.

    That is exactly right. I admit that it would be nice to have a 400 mile range EV. You still have to find someone that will let you charge it over night. I think the skeptics will start to re-think the EV when we are flooded with the goofy looking Xebra vehicles. If I had a kid in school that I was buying a vehicle for that would be it. Probably get more chicks than the jock in the Mustang or M3.
  • midnightcowboymidnightcowboy Member Posts: 1,978
    gagprice said "From what I can read between the lines, regen braking is more of a selling point than a real gain in mileage. "

    Completely wrong! Regenerative braking is the greatest gain. Think about it, you are recovering potential enegry that in every other car is compeltely lost. You are using the forward intertia of a car (Newton's 2nd law, that which is in motion thends tostay in motion) and using the load of a generator to provide braking. 100 percent gain in mileage. However GM is probably a bad example to use as your standard. Their Hybrid is not the best implementation, small battery, small electric motor , small generator = small gain in mpg.

    Ohter gains:

    (1) engine management at highway speeds: very little horsepower is required to maintain a highway speed

    Techniques:
    (A) Lower CD = less air resistance.
    (B) taller gearing more gears, CVT or wider spaced gears= taller cruising.
    (C) reduce cylinder firing and gas supply 6>3 8>4>2

    (2) lower friction

    Techniques:
    (A) Low rolling resistance tires
    (B) Lighter weight cars, i.e no power sets ,no sunrooof.

    While all help the regenerative braking converts potential energy that would otherwise be wasted to potential energy of a charged battery that can be converted back into car motion through an eletric motor later. Therefore the gain in the regenerative braking is the most important; 100% return on investment!.

    MidCow
  • tpetpe Member Posts: 2,342
    I think that my main problem with the Xebra is its 40 mph limit.
  • gagricegagrice Member Posts: 31,450
    According to the video it actually tops out about 48 MPH. Most business and residential areas are no more than 45 MPH. It is an Urban/Suburban solution for only surface streets. I make at least a dozen trips a week to town. It is 3 miles to Lowes and the library. That is the furthest those trips take us. At less than a penny a mile it is 5% of what it costs to drive my GMC Hybrid PU truck. I can get most of the stuff we buy in either the Xebra or PU model. A much more substantial savings than buying a Prius that costs about 7 times more than the Xebra for fuel. And 3 times as much to buy and insure.

    Supposedly the dealers are sold out on the first shipment of Xebras. We will see how the next batch goes. If it is like biodiesel it will take a while to satisfy the Bay area before it gets to the extreme South here in San Diego. We still do not have a dealer.
  • midnightcowboymidnightcowboy Member Posts: 1,978
    " I can get most of the stuff we buy in either the Xebra or PU model. A much more substantial savings than buying a Prius that costs about 7 times more than the Xebra for fuel. And 3 times as much to buy and insure."

    And about 10 time more likely to cuase death or substantial injury in a wreck!

    In safety size matters. In spite of all the safety features, if you run into an 18 wheeler you are toast.

    Be Safe,

    MidCow
  • snakeweaselsnakeweasel Member Posts: 19,592
    In safety size matters.

    You are making an error when you associate size with safety. A small car can be much safer than a large car.

    In spite of all the safety features, if you run into an 18 wheeler you are toast.

    I hate to tell you this but unless your in another 18 wheeler or a tank you are toast if you run into an 18 wheeler.

    2011 Hyundai Sonata, 2014 BMW 428i convertible, 2015 Honda CTX700D

  • rorrrorr Member Posts: 3,630
    "I hate to tell you this but unless your in another 18 wheeler or a tank you are toast if you run into an 18 wheeler."

    Agreed.

    I saw the results of a Semi-truck vs. Expedition encounter about 6 months ago. The Expedition lost.

    I have no idea why the "if you run into an 18 wheeler..." argument is ever used... :confuse:
  • tpetpe Member Posts: 2,342
    Well if you plan on driving around a vehicle as small as an 18 wheeler you better hope that you never run into a freight train.
  • rorrrorr Member Posts: 3,630
    Very true.

    And if you run a freight train, you need to watch it around drawbridges and container ships.....
  • midnightcowboymidnightcowboy Member Posts: 1,978
    whoosh! -Geeze the 18 wheeler was an obivious example.

    If you don't understand that I am not sure. let's try e;ementary pictures.

    2000 lb EV -> <- 3500 lb sedan

    MidCow
  • terry92270terry92270 Member Posts: 1,247
    Electric carts belong on the sidewalk, in yards or large empty parking lots. Certainly not on streets. :P
  • midnightcowboymidnightcowboy Member Posts: 1,978
    whoosh! -Geeze the 18 wheeler was an obivious example.

    If you don't understand that I am not sure. let's try elementary pictures.

    2000lb EV .......................... 3500 lb sedan
    ..........2000lb EV ......... 3500 lb sedan
    ..............2000lb EV .3500 lb sedan
    ....2000lb EV |3500 lb sedan
    @EV@ ... 3500 lb sedan
    @3500 lb sedan

    MidCow
  • midnightcowboymidnightcowboy Member Posts: 1,978
    Is the Prius an electric cart ? where can TPE drive?
  • terry92270terry92270 Member Posts: 1,247
    The Prius, contrary to the wishes and hopes of some people, is a Hybrid. It was designed and specifically intended to run on both gasoline and batteries. :P
  • gagricegagrice Member Posts: 31,450
    You must be in a very sheltered environment. We have those little 3 wheel electric wheel chairs everywhere around here. I guarantee they do not consider the road off limits. It is a new age and lots more to look out for out there. You would think they were only for those less fortunate than we, until they pull up to a store and jump off and go in. Most stay on the sidewalks. We have narrow streets with no sidewalks and you slow down behind them or end up in an accident. At least a Xebra will keep up with traffic. I say bring em on.
  • snakeweaselsnakeweasel Member Posts: 19,592
    And if you run a freight train, you need to watch it around drawbridges and container ships.....

    True and if you run a container ship you need to watch it around breakwalls.

    2011 Hyundai Sonata, 2014 BMW 428i convertible, 2015 Honda CTX700D

  • tpetpe Member Posts: 2,342
    Well that's a problem for the person driving the 2000 lb EV to worry about. As long as the EV keeps up with traffic by your rational it should actually make the roads safer for the driver of a larger vehicle. I mean if you're the driver of the 3500 lb sedan would you rather run into a 2000 lb vehicle or another 3500 lb vehicle?
  • snakeweaselsnakeweasel Member Posts: 19,592
    Well he is suffering from the fallacy that larger is safer. It is possible to make that 2000 lb EV as safe as that 3500 lb sedan.

    2011 Hyundai Sonata, 2014 BMW 428i convertible, 2015 Honda CTX700D

  • gagricegagrice Member Posts: 31,450
    Or would you like to be hit by a 6000 lb PU, which is more likely in your part of TX.
  • terry92270terry92270 Member Posts: 1,247
    "I'm a little rascal on my little Rascal!"
    --Popular US Television Commercial


    Out West, we ticket them old timers, stuff them into a real car, and take them back to the old folks home. :P

    Seriously, I am in DC several times a month, and have yet to see one of those carts anywhere near the icon buildings, in Pentagon City or Suitland. I guess I really need to get out into the real world of rural and coastal Maryland more, as opposed to rural Northern Nevada..... ;)
  • reddroverrreddroverr Member Posts: 509
    Could be made safer of course, but the price they are listing is not cheap already for a glorified golf cart. Someone posted statistics on one of these boards showing that in the real world cars of today, more weight is safer. Now whether that is significant for a lot of drivers is a different story.

    Looking at that Zebra, I can see the local teenagers engaging in a new sport...car tipping.

    I guess we all have different things we will accept in a car. The Ev Colt sized machine with a range of 90 that can handle freeway speeds is about as bare bones as I could live with..and hopefully I can get more than that in a few years.
  • gagricegagrice Member Posts: 31,450
    Lots of folks like the weather in San Diego. So they come here to retire. Also we have a very large veterans population many of which are disabled. You can drive your electric wheel chair around here 365 days a year. I see them every trip to town along the road. They will go 3 or 4 miles to the grocery store or where ever. Mobility is the name of the game. They have vans that pick them up for longer trips downtown or to the malls. The Trolley has a lift.

    The price of the Xebra is very competitive. I see the golf carts on the street many are close to 20 grand. They are limited as they only go 25 MPH and are technically not allowed on any roads posted 35 MPH or higher. They do block traffic on the section that is 40 MPH speed limit. I like the cost to operate at under a penny a mile. It would be good for Edmund's to do a TCO on the Xebra when it becomes mainstream.
  • gagricegagrice Member Posts: 31,450
    Ev Colt sized machine with a range of 90 that can handle freeway speeds is about as bare bones as I could live with

    I just don't see myself on the freeway with anything smaller than our LS400. I prefer a PU truck or Suburban. That is why the Xebra size does not bother me. I am not going out into the craziness on the freeways with any small car.
  • tpetpe Member Posts: 2,342
    Someone posted statistics on one of these boards showing that in the real world cars of today, more weight is safer.

    Let's say that's true. Just another reason to go EV. At the present time to achieve a range of 200 miles is going to require a 1000 lb battery pack. Don't just think of it as energy storage but think of it as 1000 lbs of safety. And unlike gasoline the weight of this battery pack will always be with you providing the same level of energy efficient safety even as it discharges.
  • reddroverrreddroverr Member Posts: 509
    We are all different. My first car was a Colt so I was aclimated young. Unfortunately, people get T-boned big time on surface streets too. Happened to a friend of mine last year. Just have to do whatever makes one comfortable with the risk and not worry about it after that.
  • reddroverrreddroverr Member Posts: 509
    I tried to resurrect the link, but I couldn't find it. Placement of batteries as opposed to engine in front might skew things. Weight tranlated to size, I would think.

    As I say, we draw all draw the line somewhere. Subcompacts like Fit is about where i draw. I have virtually no interest in a Smart car or Zebra. I would prefer a car up to the size of about a Camry..after that I don't see much additional appeal for me. But others differ of course...but I tend to think that the market for Zebras given all the limitations is truly small. No real facts to back that up.
  • tpetpe Member Posts: 2,342
    I apoligize, my post was somewhat facetious. It was more in response to comments that nobody would want an EV because energy density of batteries is nowhere near gasoline.

    I agree that the market for Xebras will be pretty small. You don't need a big market to make a profit. There's around 10 million vehicles sold each year in the US. 1/10 of a percent would be 10,000 vehicles. I think that Zap would be ecstatic selling half that amount.

    As far as battery placement goes, that's actually another EV advantage. There is a lot more latitude involved here as opposed to distributing the weight in an ICE. The term being used is skateboard design. This allows for considerably more flexibility in the design of the exterior and passenger compartment of the vehicle. It makes sense. It's pretty difficult to distribute the weight of an engine and transmission. Not so difficult to distribute the weight of batteries.
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