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Featured Bosch 48V battery

Discussion in 'Prius, Hybrid, EV and Alt-Fuel News' started by bwilson4web, Oct 15, 2017.

  1. GT4Prius

    GT4Prius Active Member

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    Ok, but I think that was just engine start stop when stationary and idling. Much simpler and easier to achieve than what the Ecomatic Golf could do.

    According to this, Toyota were the first to do that, in 1970s!

    Stopp-Start-System – Wikipedia

    Posted via the PriusChat mobile app.
     
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  2. bwilson4web

    bwilson4web BMW i3 and Model 3

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    There are reports that FCA will have 2018 models with 48V electrical: AD #2259 – GM Pulls the Plug on the Volt, ZF Uses Blockchain For Car Sharing, Can Tesla Hit Its Goals? – Autoline Daily

    Meanwhile, FCA is going almost across the board with 48-volt hybrid technology on most of its light vehicles. It’s a belt-alternator-starter, or B-A-S system with a 48-volt lithium battery and a heavy-duty alternator which does double duty as an electric motor. At least some of these systems will be supplied by Continental. The BAS (bass) provides stop-start capability and provides some torque to the engine in low speed situations. We drove the new Jeep Wrangler with a 3.6-liter V6 without the BAS, and another a 2-liter turbo with it. The 2-liter with the BAS was two seconds faster in 0 to 60 runs and delivered 2 more miles per gallon in our real-world driving.

    I remain skeptical because comparing two different sized engines violates the engineering principle of holding everything constant but one test variable, the 48V BAS. So I started Googling to find more technical details and came across this advocacy piece: https://www.arb.ca.gov/msprog/consumer_info/advanced_clean_cars/potential_efficiency_and_cost_benefits_of_48v_systems_and_synergistic_technologies.pdf
    • P0 front of engine - least capable but cheapest manufacturing cost.
    • P1 like the old Honda IMA - more expensive but just P0 moved to the other side
    • P2 IMA with engine side clutch - even more expensive but finally avoids engine drag
    • P3 to the transmission - starting to look like a true hybrid
    • P4 to the wheels - now we're starting to look like a serious hybrid, go-cart sized
    The rest of the paper inadvertently states my problem with 48V systems that don't have the energy to significantly improve mileage performance. Rather like the old Honda IMA, it tweaks edge cases of the engine to make it less bad. For example, the paper shows the compression ratio increased from 10 to 12. The longer power stroke alone improves Otto engine efficiency.

    I did find one credible comparison: Compare Side-by-Side
    • no 2.0 liter turbo listed
    • a 2 MPG difference between the "new" and original
    Just we need to understand what the difference is between the "new" and regular Wangler.

    According to this report from the LA Autoshow: All-new 2018 Jeep Wrangler specs released at LA Auto Show

    Jeep promises that a 3.0-liter diesel and a hybrid-electric option are also coming, but has not yet released specifications for those. Most assume that the hybrid won't be around until 2019 while the diesel will be introduced sometime mid-year in 2018, having only recently received US government approval.

    Bob Wilson
     
    #22 bwilson4web, Dec 27, 2017
    Last edited: Dec 27, 2017
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  3. TMR-JWAP

    TMR-JWAP Senior Member

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    As a side note to the 48v systems, I seem to remember reading that higher voltage systems (like 48v) were needed in order to optimize variable position solenoids for intake/exhaust valve positioning. This was a possible replacement for camshafts to allow infinite tuning of an engine for maximum efficiency at all rpms. Kind of like coil-on-plugs, but coil on valve stem. Anyone else remember that subject from a few years ago?
     
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  4. austingreen

    austingreen Senior Member

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    Mazda and fiat seem to have the least expensive but highly functional variable lift electronically controlled systems. These both use 12V and alternator systems. The big efficiency savings are on the beefed up starter or mg, along with electronically boosted power steering and electronics for heated seats, radar cruise control, etc.

    IMHO the first thing to look at is could one of these 48V systems run something like the prius hybrid system? The 2018 camry hybrid le uses a 70 cell in series 259 V @ 4ah (1 kwh) providing and additional 24 kw (assuming at the motor shaft) to system power. That means its pumping about 120 amps max to the inverter. Put some pretty simple circuitry in there like tesla uses in its packs and make a 48 V battery out of 13 series groups of 6 cells in parallel (78 cells). Now you have a 48.1V @ 24ah - 1.15 kwh battery that could easily power the same things pumping about 665 amps max (assuming 3% less efficient at max power), which is pretty common for 12 v systems now. 48 V system would be fine for the prius, prius c, or camry hybrid system, but a little less efficient.

    Which asks what do you get by going 48 instead of 144V (prius c) - 259 V (2018 camry lithium). The answer is if you get volume, then lower prices.

    Start stop systems are going to sell well in China and Europe, which will drive down prices. AGM lead acid batteries which are currently used may well be more expensive than a dual voltage system (48&12) with a dc converter in between. The question is really cost of the lithium 48v + converter versus a larger 12v agm battery and probable replacement as the lithium should last longer. As lithium battery and dc to dc converter prices fall, that dual voltage will become less expensive. JCI already has such a battery with lithium 48v + dc coverter + lead acid 12 v in a single battery package for new designs, and they sold 8 million agm batteries in new start stop cars last year. 48V is probably the right voltage for electric assisted steering and brakes, heated seats, electric super chargers, etc. 48 v doesn't have the safety regulations and additional requirements of voltages over 60 VDC. My guess is around 2020 there will be standardized 48V components that are less expensive than the ones in current higher voltage hybrids and plug-ins.

    Now once you have that system, a little more juice and a BAS system is not much more expensive than a start stop system. I would expect motors replacing flywheels on manual transmission start stop engines. I would also expect more pancake motors in full hybrid configuration with a dry clutch between a motor and auto transmission as hyundai, vw, bmw, and mercedes do today. For the US and Japanese markets I don't expect bas will ever sell, it doesn't get you points on the epa test like it does on the european one, and japan seems to regulate towards full hybrids. The chinese and european markets may make things in expensive enough to see more 48V full non-plug in hybrids in the US. Samsung and Toyota are both working on SiC converters which would reduce losses in inverters about 10%, which makes the lower voltage not as lossy ;-) For plug-ins, they may use 48V components, but will use higher voltages. 100 KW is over 2 KA, which makes cables more expensive.
     
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  5. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I've just downloaded a copy of a Wards summary report on 48V systems:
    The Electrification Suite: four reports detailing new tech in automotive

    This summary includes power requirements tables not found in less technical reports. However it also contains the 48V mantra, "do not need additional safety precautions." A mantra is a mythical set of words that substitute for an engineering analysis. Another example, fuel cell advocates have "water from the exhaust."

    I've got to run some errands but my initial scan is consistent that the 48V systems are a diesel advocacy approach. Everything points to fixing the diesel problems. However, it turns out it is the world-wide imposition of stringent emissions levels that drives this late approach and their desire to preserve existing, engine powered vehicles. Their design engineers have been asleep for 20 years:

    Toyota introduced the Prius, the world’s first gas-electric hybrid in 1997. Thirteen years later, in 2010, Nissan launched the Leaf electric car employing a lithium-ion battery.

    In between, automakers tinkered with various combinations of partially electric-powered cars including plug-in hybrids. The Chevrolet Volt went on sale in December 2010, the same month as Nissan’s all- electric Leaf.

    Yet, as the industry strives to meet more stringent fuel-economy and emissions targets, hybrids and fully electric vehicles have struggled to gain a foothold in the market, while the cost of building those vehicles has remains high. OEMs are looking for other, less expensive and less disruptive ways to hit fuel economy and emissions targets.

    . . .
    Hybrids (both full and plug-in) and EVs require new vehicle platforms and substantial investment in new powertrain component production including batteries and motors, making them a higher- risk proposition for relatively small-volume sales.

    Apparently the Japanese have already solved the emissions problem:

    Japanese automakers met the nation’s 2020 emission targets for passenger vehicles seven years ahead of schedule in 2013. According to a report by the Japan Automobile Manufacturers’ Association, the nation’s automakers achieved 21.3 kpl (60 mpg) levels, 1.0 kpl (6.8 mpg) above the government mandated target of 20.3 kpl (57.3 mpg).

    Here are the cost estimates:

    Current estimates put the cost of 48V systems at between $1,000 and $1,200, specifically for a battery, 48V belt-starter generator, power control unit, and DC-DC converter.

    This compares to $2,000-$3,500 for a full hybrid (Toyota’s power- split system is believed to cost between $2,000 and $2,500 including the nickel-metal-hydride battery), $5,000-$6,000 for a plug-in hybrid, and $5,000-$8,000 for an EV powertrain. At the low end: $250 for a 12V electrical system for advanced stop-start systems.

    Matti Vint, Valeo’s North American engineering R&D director for powertrains, reports that the payback for an EV at current gas prices is seven years. For a plug-in hybrid: 10 years.

    He estimates that half of mild-hybrid system cost is for the battery. “That is obviously the weak link in the cost-benefit ratio,” he says. “How to get the battery cost down is key.”

    The utility of this report are the insights to how the traditional manufacturers see the problem. They want to preserve their gas and diesel investments at all cost yet face a world wide insistence on breathable air. They can't do it with ordinary ICE vehicles and hope to do it 'on the cheap.' So in this report, they report these costs:
    • $250 - 12V START/STOP
    • $1,000-$1,200 - 48V systems
    • $2,000-$3,500 - a full hybrid
    • $5,000-$6,000 - a plug-in hybrid
    • $5,000-$8,000 - EV powertrain
    Because of Toyota's hybrid baseline, their plug-in hybrids have an exceptional price-performance advantage. Ford did well too. The Pacifica is a nice package too.

    Bob Wilson
     
    #25 bwilson4web, Jun 5, 2018
    Last edited: Jun 6, 2018
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