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The Future of Hybrid Technology

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  • gagricegagrice San DiegoPosts: 28,850
    Big whoop if an 18 MPG SUV gets bumped up to 22.5 MPG. Who's gonna pay extra to get that tiny bump?

     

    I agree, especially when you can get that kind of mileage with the diesel that is available in the big 3 trucks. Plus the much greater towing capacity. I don't see much advantage to hybrid trucks. I'm not sure of their motivation unless it is to meet the new CAFE truck standards.
  • yerth10yerth10 Posts: 428
    Will it make sense to classify Hybrids as

    H1 - Mild - Stop & Start

         Chevy Silverado, Citroen C3

     

    H2 - Partial - Motor supplementing Engine

         Honda Civic / Accord

     

    H3 - Full - Motor powering vehicle at low speed

         Toyota Prius, Ford Escape

     

    H4 - Plugin - Facility to charge from grid

     

    H5 - Plugin/Bifuel - Facility to have 2 fuels like

         Gasolene / Ethanol

         Diesel / Biodiesel

         Gasolene / LPG

         combined with Plugin facility.

     

    H6 - Plugin/FC - Fuel Cell along with Plugin.
  • gagricegagrice San DiegoPosts: 28,850
    I like H5, more options.....
  • The usual terms are "parallel" (wheels driven by both engine & motor) and "serial" (engine has no connection to the wheels).

     

    All the hybrids made by Ford, Toyota, Honda are parallel.

     

    Some people would rather see a serial hybrid (engine not connected to wheels), because they say it would be more efficient.

     

    troy
  • robertsmxrobertsmx Posts: 5,525
    Some people would rather see a serial hybrid, because they say it would be more efficient.

     

    These people may not understand pros and cons to the extent engineers do. Honda showcased a hybrid scooter prototype last year which has a dual hybrid set up... Series mode in cruising situations, and parallel mode in power demand situations. You can read about it here.

     

    It is always about compromises.
  • I don't know. I think serial hybrid makes sense. You could drive about 100 miles on pure Electric for your daily commute & recharge at night.

     

    Meanwhile the engine just sits there until you take your weekend trip to see grandma/grandpa -or- to visit the beach some ~200 miles a way. Then the engine turns on & charges the battery.

     

    A serial hybrid provides the best of both worlds:

    - clean EV power for daily commutes

    - an engine that can provide unlimited range

     

    .

     

    Like I said, none of the current hybrids are serial (no connection between engine & wheels). They are parallel.

     

    Troy
  • robertsmxrobertsmx Posts: 5,525
    What you’re asking for is Honda EV-Plus with ICE used as on-board (electricity) generator. This will require a very powerful electric motor (Honda’s AC motor tops out at 80 HP) and ultra-capacitor/battery pack to match the power demand against whatever the generator can provide. You’re already up to 3500 lb. vehicle with EV-Plus (even if 500 lb could be shaved off, that would still make up for 37.5 lb for each HP).

     

    At this point, we don’t know what the fuel economy would be like with the generator behind the battery pack.

     

    And yes, I too said there aren't any hybrid cars that are serial (diesel locomotives, and the Honda's Hybrid Scooter prototype are though).
  • Yeah, but a serial hybrid would be designed for only 1/4 or 1/2 the range of the EV-plus, and the battery would also be downsized to 1/4 or 1/2... thereby making the car lighter.

     

    Fuel economy would be irrelevant if you're driving around on pure EV every day.

     

    Troy
  • daysailerdaysailer Posts: 711
    Oh, it may SEEM to make sense to the casual observer - until you consider all those pesky compromises that Robertsmx mentioned.

     

    First, a series hybrid requires that the electric drive provide the FULL power requirement of the vehicle, unlike the parallel hybrid where electric drive bears only part of the burden. This entails increased mass which requires more power which entails more mass .. etc. But, you might say that the ICE (and its requisite generator) can be smaller, and you'd be right. BUT, as the ICE/generator power output decreases, the battery capacity must increase - and batteries are even more massive and require more propulsive power which entails more mass, etc. But, you may say, transient power requirements can be addressed by capacitive storage which offers high power density (although low energy density), and again you'd be right, and this would reduce mass somewhat (but still more than a parallel hybrid), but you mentioned EV operation and utility grid charging. In fact, you suggest 100mile range on battery alone which is tantamount to asking the most abbitiuous EV yet produced to bear the ADDITIONAL burden of an ICE, generator, fuel system and other ancillaries. EV technology has yet to produce a practical vehicle due primarily to the low energy density and high cost of batteries, and you suggest further increases to vehicle mass and cost while increasing power requirements with the addition of the ICE et al!

     

    Compromises abound in any design - there is NO free lunch! Consequently, one must decide what objectives are realistic to pursue. If your objective is to extract the highest efficiency from a petroleum fueled vehicle, the parallel hybrid is the most promising technology to date and may even approach economic justification in the forseeable future. EV technology has yet to approach a practical replacement for the ICE vehicle and cost remains in the twilight zone. To suggest adding more cost, mass, etc by adding series, plug-in hybid technology will not improve the picture. It's no coincidence that Chrysler has chosen their gargantuan Sprinter van as a platform for plug-in hybrid windmill flailing.
  • robertsmxrobertsmx Posts: 5,525
    EV-Plus had an “ideal” driving range of something like 120 miles. ¼ to ½ of that would be just 40-60 miles under ideal conditions, and worse in less than ideal.
  • Daysailor... I disagree.

     

    .

     

    EV Motor = ~100 hp peak/25hp sustained does not weigh that much. Prius carries two of these.

     

    Battery = ~50 miles would be about 200 pounds... probably the heaviest piece in the car...

     

    Engine = ~30 hp... just large enough to charge the battery when empty

     

    troy
  • robertsmxrobertsmx Posts: 5,525
    How have you arrived at these numbers? Battery pack will weigh depending on its size. And more likely than not, the 30 HP motor is going to be one of the heavier pieces in the car (besides the powerful electric motor, as well as the transmission).

     

    PS. NiMH battery pack in Civic Hybrid weighs just 44 lb (20 kg).
  • I conferred with some EV experts (people who build electric cars for their own use!). Here's what they estimate:

     

    "Prius is about 3000lbs. Eliminate the NIMH battery pack and transmission and halve the gasoline engine to save 500lbs."

     

    "Add a 350lb NiMH battery pack for 50 miles of EV-only range and budget 150lbs toward a 100hp electric motor and you're done."

     

    "Weight is the same. And you now have a TRUE hybrid with EV only capability & unlimited range."

     

    troy
  • robertsmxrobertsmx Posts: 5,525
    You cannot cut the gasoline engine in half and trim the weight by 50%. It is not a linear relationship. Most of this discussion is based on assumptions and it won’t help to establish anything concrete. If things were that simple, you would have seen automotive giants step on it. Building anything involves enough compromises. You pick some for others, based on needs.

     

    And there is no “true” or “false” hybrid. Just two ways to go about hybrid design: Serial or Parallel. Or, it can be a combination of both (as in the Honda Hybrid Scooter Prototype).

     

    Take your guess why Honda engineers might have implemented series/parallel to co-exist in the hybrid system? Going with series only shouldn't have made a difference in any other way but improvement, correct?
  • You only need 1/3rd the power of the Prius engine, which should be doable in half the weight.

     

    Another way to show weight isn't a problem is to take an electric car (e.g. Rav4-EV), subtract half the batteries and add the 39hp TDI engine found in the Smart. It weighs 30 pounds and has more than enough power.

     

    Now you have a Rav4 serial hybrid that can do 50 miles pure EV, weighs less, & has no distance limitation.

     

    troy
  • larsblarsb Posts: 8,204
    Troy, are you talking about THIS RAV4:

     

    "Toyota has just introduced the $43,000 RAV4 EV, the first compact sport utility vehicle for the retail market fueled by household current."

     

    That one? That is not a serial hybrid, it's an EV.

     

    Where is info on the "serial hybrid RAV4" that has no distance limitation? I cannot find anything on the web about such a car.
  • robertsmxrobertsmx Posts: 5,525
    In theory, a lot of things are possible. As far as reality is concerned you did not respond to a question from me.

     

    Why do you think Honda engineers incorporated serial AND parallel mode of operation in Hybrid Scooter prototype?
  • gagricegagrice San DiegoPosts: 28,850
    "Toyota has just introduced the $43,000 RAV4 EV, the first compact sport utility vehicle for the retail market fueled by household current."

     

    No wonder they had a hard time selling them. That is pricey for that car. Probably $15K in batteries. I wonder if a guy could find a good buy on a used one.

     

    http://www.toyota.com/html/shop/vehicles/ravev/rav4ev_0_home/
  • Why is it so many times suggested that the hybrid battery in the hybrid cars is going to be soooo expensive at the end of the next 7-8 years. Remembering everything electronic usually drops in cost when marketing in mass numbers follows. Examples....VCR's, DVD's, Cellphones,Digital Cameras, etc. It is said that Big Screen TV's will eventually drop another 40-60% in the next 5 yrs. Why are there so many doubters out there with less than adequate info or is it just that some choose to be negitive?

    Culliganman(give a hybrid a break)

    PS..Car&Driver, MotorTrend, Consumer's Report ETC.. They can't all be wrong!
  • gagricegagrice San DiegoPosts: 28,850
    Why are there so many doubters out there with less than adequate info or is it just that some choose to be negitive?

     

    Can you give me an example of a NiMH pack that has gone down in price? Every time I buy a new laptop battery they are more expensive. I think hybrid batteries will be the same. Someone just posted the price for a Prius battery at more than $5200. Hope you have something saved for a replacement or dump your car before the 100k miles is up.
This discussion has been closed.