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Chevy Bolt Regen vs Tesla

Discussion in 'Model S: Battery & Charging' started by jchag, May 1, 2017.

  1. Boatguy

    Boatguy Member

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    I've had an i3 for almost 3yrs and test drove the Bolt recently. I think the difference in the regen is the motors. The regen in the Bolt and the i3 will bring the car to a complete stop, whereas the Tesla regen fades out at about 2-3mph. My understanding is that the Tesla has inductive motors while the i3 and Bolt have fixed magnets. The fixed magnets are operating at any speed, the inductive motors don't have any resistance at very low speed.

    But more important is the regen from 15mph+ and I believe the Tesla has plenty of regen at those speeds.

    The bottom line is efficiency. My i3 weighs a little more than half (2,600lbs) of the Tesla's 5,000lbs, but uses about 240Wh/mi, while my MS averages about 315Wh/mi in 70% / 30% around town / freeway driving. So the i3 is about 50% of the weight but uses about 77% of the energy. On a Wh / pound, the Tesla is much more efficient. And the Tesla's superior aerodynamics are not an issue when the average speed is 30mph.

    That said, it is a little annoying to have to always use the brake pedal on the MS and I enjoy the ability to be entirely "one pedal" in the i3!
     
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  2. Bangor Bob

    Bangor Bob Member

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    Don't ever ride a single-cylinder motorcycle. Abruptly closing the throttle in a low gear can actually cause the rear tire to pulse between locked and turning (on dirt, anyway).

    Really though, regen on the throttle has a perfect analog in driving a manual ICE - progressively let off the throttle and the car slows more and more rapidly due to the work of pulling a vacuum in the cylinders as the throttle plate closes... Except in an EV you actually get something back.
     
  3. Bangor Bob

    Bangor Bob Member

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    I suspect the Bolt and the i3 are applying a little reverse torque via the drive inverter at low speeds to bring them to a stop. My Volt is permanent magnet, and it seems to keep rolling at 2-3mph forever. But I think it has a "creep mode" permanently turned on.
     
  4. David99

    David99 Active Member

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    Tesla could adjust the regen to be stronger but for some reason they don't want to. After reading here for three years I think the majority wants to have a stronger regen option.
    The motor type is not why Tesla does not come to a full stop with regen. It could be programmed easily with an induction motor. Again, it's Tesla's choice. Most people that have driven the i3 that makes the car come to a full stop super smooth prefer that behavior. I wish Tesla would make it an option. Instead they added 'creep' as an option.
     
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  5. Lon12

    Lon12 Member

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    I totally understand where you are coming from. I drove the Toyota hybrid system for almost 10 years before getting my model S. I had the same thoughts as you for the first few months of driving single pedal. The Toyota system is very smooth but the amount of regen is insignificant compared to what Tesla is recovering.
    Now that I've been driving the model S for almost two years I'm totally over it and LOVE the single pedal driving.
    My 2011 Leaf has regen on the brake pedal and it is hideously bad. The transition from regen to brake application is not smooth.
     
  6. Lon12

    Lon12 Member

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    Ya. I understand. I was just having fun with "alternative facts". :)
    I finally got to sit in a Bolt last month. Looks like a great car for most folks. Unfortunately I will never be able to forgive GM for what they did to the EV1. So I boycott them for that reason alone.
     
  7. Boatguy

    Boatguy Member

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    I also test drove the Bolt and it felt like a Chevy with lots of bad design decisions. The lift over for the trunk was enough to discourage my wife. Read the back stories and learn that GM did not commit engineering resources to the project in any significant manner. It's not the vanguard of a transformation of GM, it's a pure compliance car. GM has admitted they are losing $9K / car which is pretty crazy for a car that costs $40K (the "premium" package of basics adds a lot of cost to the car).

    While we see Toyota, BMW, Mercedes and VW making aggressive announcements about EVs, GM is silent. They announced 10 EVs and hybrids for China by 2020, but I have a hunch those are going to have a lot of Chinese content which may raise the top line, but won't contribute to the profitability. Mary Barra is a GM lifer and just as clueless as her predecessor Rick Wagoner and will drive SUVs and pickup trucks into the sunset. GM is going to die a slow death as a zombie company with lots of volume, no innovation and no profit. Hopefully this time the government won't bail them out. They need to die and make way for innovative companies.
     
  8. Cosmacelf

    Cosmacelf Well-Known Member

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    Anyways, yes, it seems that Tesla has fallen behind the times. All newer EVs have single peddle regen to a stop. It would be nice if they were able to catch up. They've also fallen behind on CarPlay/Android Auto integration.
     
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  9. BrettS

    BrettS Member

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    Pretty sure they were never ahead here. Or even close.
     
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  10. ApauloThirteen

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    #30 ApauloThirteen, May 4, 2017
    Last edited: May 4, 2017
    Hear hear. I'm pissy at GM for their (mis)handling of the ignition fiasco and the fact that for every Bolt they sell, they then can sell a large, lumbering SUV or two (fleet mpg reqs). Whereas for every Tesla it sells it.... provides profit to plow back into selling more powerwalls, solar roofs and other s≡xy Teslas... Hmmmm...... Vote with your euros, dollars, crowns, yen, yuan, pounds, ducats, clams.... :)
     
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  11. TomatoOne

    TomatoOne Member

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    The emergency stopping is easily solved by teaching yourself to left foot brake. This way you can feather the accelerator between go/coast/regen, and the left foot comes in automatically when you need to stop quickly.

    Unlike most ICE cars, Tesla does not allow simultaneous operation of both pedals, so smoothly rolling off the brakes and into the accelerator to balance the car through the corner is not possible, but no one really tracks these cars, so it's less of a concern.
     
  12. Jeff N

    Jeff N Active Member

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    I guess it depends on what you consider "significant".

    LG designed and manufactured a number of key components but many of them would have normally been supplied by some 3rd party auto supplier for a non-EV vehicle design at GM or most other larger automakers. GM and LG did a deal that directed a higher percentage of those parts to LG whereas they would normally have been spread across several different suppliers. We're talking here about display screens, infotainment center, AC compressor and climate controls, AC to DC battery charger, Green PHY communications module, etc. Other suppliers still provide the braking system, wiring harnesses, seats, steering rack, etc.

    A number of the key powertrain components were designed by GM but are being manufactured by LG such as the power inverter and drive unit that contains the motor, gearbox, and differential. That's not unique to the Bolt. GM contracts with Hitachi Automotive to manufacture the power inverter and motors in the Volt PHEV although it made its own parts for the Spark EV. Companies contract out because it's sometimes cheaper while other times it's cheaper to do it in-house.

    GM also designed the car body using a fairly sophisticated multi-material approach to reduce vehicle weight at its Korean small vehicle design center. As part of that they closely collaborated with LG on the structural design and other aspects of the battery pack. GM did a lot of design verification and environmental testing. GM did the full vehicle integration engineering. Final assembly is at a GM factory in Michigan.

    Doing all of that in the span of ~3 years inherently required a great deal of engineering resources most of which is directly applicable to the design of future EVs.

    GM has not "admitted they are losing $9k / car". That number came from an anonymous source quoted in a Bloomberg or Reuters report (can't remember which) and the details and assumptions being that number were never qualified in any useful way.

    Huh? Why would the fact of them being Chinese models built in China not contribute to GM's profitability? Of course they are going to have Chinese content and be built in China just like Toyota and Honda build cars in the US or the North American market. The car designs themselves could easily be manufactured and sold in the US market and some likely will. GM's Chinese cars are mostly the same as models sold in the US with minor cosmetic differences. I was in Shanghai a couple of years ago and the streets were filled with cars that looked pretty much the same as what you would see in a major US city.

    GM is very profitable at the moment with less debt after the bankruptcy and a much stronger line of smaller cars than they had in the past. They finally have competitive hybrid cars (Chevrolet Malibu at 46 mpg EPA) and the Volt (which shares the core transmission design with the Malibu) was the first PHEV and still is one of the best selling plug-in cars. A version of the Volt is now selling in China. GM also just began selling a CT6 PHEV with a RWD hybrid transmission likely to see broader use in SUVs and trucks. With the original Volt and the newer Volt/Malibu and CT6 hybrid transmissions and the Spark and Bolt powertrain designs GM has been doing a lot of engineering innovation in the electrified vehicle space in the last 10 years. They are well-positioned technically for the next decade.

    I agree that GM has only vaguely committed via a brief comment by CEO Mary Barra to multiple new EVs for the US. I agree they need to step up and clarify their North American EV strategy soon.
     
  13. McRat

    McRat Well-Known Member

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    Boat Guy is just chumming the water. Note he did not mention regen at all.

    Nothing in his post is even vaguely related to EV technology.

    Heck, he even thinks Toyota makes a great EV in 2017.

    Sort of like a 5 year old lecturing you on sex.
     
  14. Snerruc

    Snerruc Member

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    Funny, myS comes to a complete stop at stoplights on regen. I usually only hit the pedal to set hold.
     
  15. jchag

    jchag Member

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    I wish mine would
     
  16. EV-lutioin

    EV-lutioin Active Member

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    When I test drove the Bolt the regen very strong, it seemed odd to have to choose it with the gear selector every time you get in the car, I would prefer to just set it and forget it. I would think it would be easy for Tesla to add a full stop regen as well... simple software update??
     
  17. Jeff N

    Jeff N Active Member

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    For context, it takes all of about 1/4 second to put it in high regen mode. You just toggle back an extra time with a flick of your fingers when shifting to drive.
     

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