Delphi 48-Volt (nonsense)

Discussion in 'EV (Electric Vehicle) Discussion' started by bwilson4web, Dec 16, 2015.

  1. bwilson4web

    bwilson4web BMW i3 and Model 3

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    48-Volt Infographic


    Source of source: AD #1765 – Chinese EV Startups Flock to Silicon Valley, Suppliers Bet on 48-Volt Systems, Ford GT to Use Gorilla Glass – Autoline Daily

    So this is what I posted in the comments:

    The 48V ‘mild hybrid’ is a dead end because it continues to run the engine when it should be off. The Prius ‘secret’ is turning off the engine which avoids unnecessary engine overhead.

    Starting motors run just under 5 HP, the mechanical overhead of the engine. Even at idle, the engine has to burn enough fuel to overcome engine mechanical overhead. So a Prius sized car needs 5 HP at 45 mph to maintain speed (see username link.) By running the engine constantly, at 45 mph, 50% of fuel is wasted on engine overhead.

    In contrast, the Prius frequently turns off the engine, saving 5 HP of engine overhead and maintains speed with the stored energy. When the electrical energy runs low, the Prius starts the engine and runs at just over ~15 HP: (1) 5 HP for the engine, (2) 5 HP to keep the car rolling, and (3) ~5 HP banked into the battery. Only 5/15 or 33% of the fuel is wasted on the engine overhead.

    Until the non-Ford engineers in Detroit realize maintaining speed with the engine off is the ‘Prius trick’, stunts like these 48V systems will cost too much for too little.
    . . .

    So now we know where the dumb engineers went, Delphi.

    Bob Wilson
     
  2. Trollbait

    Trollbait It's a D&D thing

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    I disagree that the 48 volt system will kill the higher voltage, full hybrid ones, but it can provide improvements over the straight ICE model.

    Let's look at the Mazda 6. 2016 Mazda 6 Sports Sedan – Specs & Features | Mazda USA
    The Grand Touring trim with technology package has the i-Eloop regenerative braking and active shutters. With these as the only difference between the GT trim and other models with the automatic transmission, the EPA rating increases by 2 mpg for both city and highway, and Mazda has yet to introduce their start/stop system, i-stop, to the US yet. So the gains to the city rating are from shifting some of the electrical load from the ICE to formally wasted brake energy, and the Mazda6 still idles at stops and hasn't gone 100% electric for accessories.

    A 48 volt, mild (could actually be called assist) hybrid should see greater gains than what this Mazda 6 sees. The A/C compressor and other accessories can become fully electric, it will have start/stop, and can use an electric super charger to downsize the ICE; another Prius 'secret'. The start/stop will be more robust than on 'micro-hybrids' that have only a single 12 volt battery, so it will provide better gains in real world stop and go drives. For full disclosure, Mazda's i-stop doesn't use the starter for restarts, but fine control of fuel injectors and ignition. GM's system on the Malibu has a second, deep cycle 12 volt in the trunk.

    It won't achieve full hybrid results, but it doesn't have too. Full hybrids are still thousands more than the ICE model. These 48 volt systems should be much cheaper, and take up less cargo space. The fact that the GT Mazda 6 with i-Eloop costs more than some of its hybrid competitors doesn't bode well for that. However, these systems aren't being developed by car companies, but car company suppliers. The potential of selling the systems to multiple car companies can bring the cost savings of larger scale production into affect sooner. there is more than one company developing such 48 volt systems, so the competition there will help with pricing. Continental is another company. Continental Corporation -Continental Presents New Solutions for Future 48 Volt Hybrid Architectures

    In short, these systems won't make full hybrids obsolete, but could be another option for consumers looking to reduce fuel consumption. It is a question of whether the price can be kept from surpassing the potential benefit.

    PS - Since is likely to come up. The Malibu with start/stop does just as well on the EPA test as the model years with eAssist. However, taking out the eAssist for start/stop wasn't the only change. The eAssist model had an old, port injected engine. when the hybrid system was dropped, the car got a new, direct injected one.
     
  3. bisco

    bisco cookie crumbler

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    the question is usually the problem.
     
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  4. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I had the pleasure of explaining in 2006 to an early adopter of the GM BAS system why it could not achieve Prius MPG. Back then GM called it a 'hybrid.' Still I'm all for improving the efficiency of existing cars.

    It looks like the base, 2015 Buick LaCrosse eAssist at 29 MPG is only $2,500 over the gas-only 21 MPG. Certainly a good deal and much better than the old BAS systems. But I'm under the impression the eAssist uses a higher voltage battery,"115V lithium-ion battery to power a 15-kW electric motor-generator" or ~20 HP. These are serious power levels.

    In contrast, 48 V is not a realistic voltage for serious traction power. The reason is (I**2)*R, the electrical losses increase by the square of the current. Their own charts say it is just for accessories, not primary traction power with the engine off.

    So who do we hate who might be dumb enough to buy this 48 V nonsense . . .

    Bob Wilson
     
  5. bisco

    bisco cookie crumbler

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    erm, a certain western/eastern european auto manufacturer with letters number 22 and 23 in their name?:whistle:
     
  6. Trollbait

    Trollbait It's a D&D thing

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    Thus a mild hybrid.

    The Mazda 6 with active shutters and i-Eloop got a 5% to 7% improvement by recapturing braking energy to power some of the accessories and improving the air flow and warm up time. These 48 volt systems can see further improvement by using an electric A/C compressor, and making use of start/stop.

    If the price is right, they can be an easier sell to the 97% of car buyers that pass over or never consider a full hybrid.

    I think we'll see it on a Chrysler mini-van first.
     
  7. bwilson4web

    bwilson4web BMW i3 and Model 3

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    More of a low-end, blue-motion, hybrid. I've long suspected the a single-motor, hybrid can approach Prius/Ford performance IF they are implemented with attention to the engine-OFF performance. The engine has to go off for a non-trivial period of time while the motor maintains speed.
    We'll have to agree to disagree about 48 V systems. The currents to handle an appreciable amount of energy are too high . . . but put one on each wheel might work.
    Well if it means they don't call it a hybrid but some euphemism that has not been slandered:
    • 'hybrid' - slandered by a decade of anti-Prius propaganda (aka., GM, VW)
    • 'clean' - VW and others killed that one
    • 'unleaded' - we may have a winner
      • more power
      • less weight
      • no toxic lead
    • 'iCar, iGo, iMotion' - second runner ups, iMay iHave iTrademark iIssue
    iBob iWilson
     
  8. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

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    48v systems are coming to cars doesn't matter if they're mild hybrids or not.
     
  9. GasperG

    GasperG Senior Member

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    Nice infographic, but I do wonder of the actual price premium over normal ICE, it says that the cost is just 30% of full hybrid, how did they evaluate full hybrid premium?

    I will try to evaluate those prices based on European Auris, that comes as:
    - 1.33 NA: 15,800 €
    - 1.2t: 16,800 €
    - hybrid: 19,700 €
    - 1.6 diesel: 18,700 €

    option for 1.2t:
    - Multidrive S: 1,400 €

    Usually price premium is calculated from the cheapest engine option, then we have 3,900 €, 30% of that is 1,170 €. From that infographic 48V system does not include any drivetrain (full hybrid includes at leas transaxle) that would mean that 1.33 NA, MT car would be 16,970 €. Good price but the performance would still be only 100 HP and it would still be a MT, can't really compare to more powerful AT hybrid.

    So we must take 1.2t + Multidrive S + mild hybrid = 19.370 €

    Suddenly full hybrid is only 330 € pricier.
     
  10. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Given how many lights, LEDs, control computers, and entertainment systems are low voltage, I don't see a 12 V power bus going away. In truth, 6 V becomes attractive except for the larger conductors and smaller inventories.

    Rather I see 200-300 V battery systems connected to a 50 kW power motor generator(s) to provide traction and absorbing regeneration power. I also see it fan out as AC voltage because this allows an arc to extinguish saving fuses and circuit breakers and transformers can convert to device voltage levels. This AC power the air conditioner system. It should also include a 12 V buck converter so when the car is turned off, the battery system runs for about a minute before shutting off the the high-loads.

    I also see integral solar cells providing sustaining power for a small, 12 V battery system powering just the keyless entry systems. This system can wake-up the 200-300 V battery system for short periods to identify where the car is parked. But a 48 V system makes no sense.

    A 48 V system has too little power capacity without huge power cables to sustain even modest speeds. Worse, there are few, 48 V accessories so 48 V to 12 V buck converters would still be needed. It is the 'clean diesel' of automotive electronics.

    Bob Wilson
     
  11. Trollbait

    Trollbait It's a D&D thing

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    What the actual price premium is for these 48 volt systems is will be the first factor on whether they are successful.

    Let's use the Sonata; it has a full hybrid that retains the 6 speed step automatic transmission. So drivetrain differences will have less impact on the price difference. The base SE trim of the ICE and hybrid model are really close in terms of standard features.
    The ICE is $21,150
    The hybrid is $26,000

    A hybrid premium of $4850.
    If the 30% holds true, then a 48 volt system would cost $1455. Which, honestly, seems low. The Sonata hybrid already has the HSG(hybrid starter generator) and much of the other hardware that a 48 volt system would have. That HSG is around a $1000 for a replacement. Could the 48 volt battery be under $500 in cost? I'll stick with that $1455 figure for now. Which would mean it is $3395 less than the full hybrid.

    The other factor for the 48 volt's success is whether it delivers the fuel efficiency benefits. The ICE and hybrid are at 29 and 42mpg combined; a 13mpg improvement. The claim for the 48 volt system is 70% of that, or 9.1mpg. A roughly 30% improvement over the ICE's numbers, with hybrid gaining 45%.

    It could be a success, but we really have to wait for an actual car with the system. It looks good using the Sonata, but the Camry hybrid has a price premium of around $3000, and $1500 is likely the lowest for these 48 volt systems.
     
  12. bisco

    bisco cookie crumbler

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    i don't really care, i'm just tired of the 'experts' saying (shilling), 'we don't really need hybrids'.
     
  13. Trollbait

    Trollbait It's a D&D thing

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    But this a hybrid.
    As the CAFE targets get higher, we will see more hybridization, to varying degrees, of cars to the point that the ICE car available at the dealer is a hybrid to some extent.
    The full hybrid isn't going away because of mild hybrid systems. That is just headline clickbait. Toyota has shown that the costs can be reduced for the full systems. But that doesn't mean a mild system with lower MPG improvements, but lower cost won't have a place also. I can see it working at both ends of the size and cost spectrum.

    At the small and low price end, we have the subcompact or B-class. The main draw of these cars is that they are cheap, yet still usable to a degree beyond commuter. Take the Yaris; it is $15k to $17.6k, and should return a little 30mpg for most. Competitors that aren't has stringy on transmission tech will do a little better there. It is small, but can do a road trip in a pinch. The Prius c will return 50mpg, and is a little bigger than the Yaris, but runs $19.5k to $24.5. For that price, or even a little less, the person can get a Corolla with the fuel economy near that of the Yaris, and is a more comfortable car to sit in every day than the c and Yaris.Compare Side-by-Side



    Most people in the above scenario will opt for the Corolla over the Prius c. A lower cost hybrid system, that still has a perceivable benefit, may head off the "I might as well go bigger" thinking, and still get more fuel saved.

    At the other end, there is the full size SUV and American size minivan. Hybrid SUVs of the past have been pricey without the wow factor in the improved MPG figures like their car brethren. So many pass over them. A mild system can succeed here by having numbers on the window sticker that look almost as good as the full hybrid's, and not pushing the price out of potential buyers' range.
     
  14. GasperG

    GasperG Senior Member

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    It could be an option for manufacturers that can't make cheap full hybrid :p

    Sonata SE is $21,750, and hybrid model does have some more features (Hands-free smart trunk, Side mirror-mounted turn-signal indicators, Proximity Key entry with push button start, LED rear and DRL, Dual front automatic temperature control, 4.2-inch color trip computer with Electroluminescent Gauge Cluster).

    We also must consider that market price is not directly related to manufacturing costs. So hybrid price premium may be misleding and not direct indication of actual cost premium.
     
  15. Jeff N

    Jeff N The answer is 0042

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    The 2016 Chevrolet Malibu hybrid LT is $28,645 (including $875 destination fee) and the apparently similarly equipped Malibu 1LT conventional trim with a 1.5L engine with somewhat lower engine power specifications is $25,895 for a hybrid premium of $2,750. The fuel efficiency goes from 27/37 (city/highway) to 48/45.

    I don't think the exact equipment specs are out yet on the Malibu hybrid so there might be some other differences.

    That means driving 100,000 miles would yield a difference of a little more than 900 gallons of gas which would reach a break-even point at about $3 per gallon.
     
  16. bisco

    bisco cookie crumbler

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    that's why we're 3% of the market. we need $5. +
     
  17. FL_Prius_Driver

    FL_Prius_Driver Senior Member

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    48V is an intermediate voltage, not a viable end use voltage. It is not a good voltage for the trillion dollar car components infrastructure since 12V works perfectly for headlight, window motors, and everything else in the cabin. There is no money to be made in making a change of all these components to 48V. At the supply end, 48V is an extremely low voltage for large capacity batteries. (Large as in being bigger than lead acid batteries.) At this low voltage the cells have to be very large and/or put in parallel...a very undesirable thing to do. The original desire was simply to reduce electrical cost with 48V lead acid batteries becoming a widespread future standard. Lead acid batteries are not a future growth business at all and will not even be an end item in future cars at some point. Delphi is just trying to push there obsolete investment in the 48V car component business. (That is what Delphi does.) The lowest cost and highest performance electrical designs will be straight conversions from ideal source voltage to ideal component voltages.
     
  18. Road Fan

    Road Fan Two-Prius 7-bike Family

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    At SAE and from my times with various OEMs and Tier 1s, I see 48 volts as the planned bus voltage for electric and electro-hydraulic steering, better heater fans, electric valves, and most of what was traditionally driven by the serpentine belt or is otherwise a large (50+ amp continuous) electrical load. For example a brake system in an EV needs a vacuum pump. If it has to support a lot of heavy braking like for an automated braking system, the pump motor might benefit from 42 (safer!) or 48 volts rather than 12. In an EV there is a variety of possible architectures; you can build those subsystems to run off the high propulsion voltage, or run a 220v (for example) to 48 subsystem DC/DC converter to drive a set of higher power vehicle subsystems, or keep the current 12 volt high-power subsystems and incorporate a 220 to 12 volt DC/DC converter.

    My experience as a power engineer for aircraft and spacecraft says you can get lower mass with higher voltage, and more effective/lower cost magnetic components with better winding factors using smaller wire. So there are benefits to raising the voltages. Are there costs? Yes, but the air and space industries have been developing systems > 28 volts for over 25 years, and in automotive I've seen 42 volts being explored and developed since the late '90s. There might be a cost advantage in certain applications by now. It's not recently new, though there hasn't been high deployment as far as I know.

    There's no substitute for high voltage if you need an auto propulsion system with the kind of power Prius and Cmax require, and of course bigger systems. They can be done with 48, but it has penalties. I have not done similar trade studies, however, for a number of years.
     
  19. bwilson4web

    bwilson4web BMW i3 and Model 3

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    In principle, I agree with higher voltages but the jump from 12V to 42-48V seems a jump too far. In contrast, heavy trucks and military vehicles have been using 24V systems for years and that makes sense. Replacing the power vampires, power brakes, steering and starters, on ordinary cars makes sense. But we're talking about intermittent, peripheral loads. What bothers me are the inflated economy gains claimed for 42-48V hybrids:
    • 745 W / 48 V ~= 15 A for 1 hp
    • full hybrid ~15 hp -> 225 A
    If they drop the inflated hybrid claims and focus on light-weighting conventional vehicles, I'm with them. But we've already seen a series of 'crash-and-burn' micro-hybrids and they just don't work. I know, GM is trying it again but the physics have not changed. IMHO, accountants are terrible engineers.

    Bob Wilson
     
  20. Sergiospl

    Sergiospl Senior Member

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