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600kw 15 second charge? Yes please.

Discussion in 'Model S: Battery & Charging' started by ebyard, Aug 10, 2016.

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  1. ebyard

    ebyard Member

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  2. lklundin

    lklundin Member

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    Yes, there is a lot of research in battery and charging technology, which is all beneficial to BEV adoption.

    The above example is for the very short and frequent stops that buses do. It charges at about 4 times the power of the newest superchargers, but only for 15 seconds, i.e. 2.5 kWh which in a Model S would translate to maybe 15 km. While a higher charging power is useful, I would not say that a small burst-charge is essential for BEV-adoption.

    But still great news. Buses are a major source of noise and emission pollution in cities, and going electric can reduce both.
     
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  3. TexasEV

    TexasEV Active Member

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    Stopping every kilometer to charge for 15 seconds and then for 5 minutes at the end of a 13km route is ideal for busses, but not really relevant for cars.
     
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  4. scottm

    scottm Active Member

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    Now, if busses ran on electrified rails and charged continuously they'd never need to stop to get a charge.

    Hey wait! They wouldn't need batteries either!!

    Hasn't this been done before?

    Our city got rid of the last trolley bus in 2009 and decommissioned 127 km of lines.

    Now considering putting in BEV buses like those running in a neighboring city that go 100km on $12 of e-juice as opposed to $60 diesel. Those buses recharge en-route in 20min for full charge.

    I definitely remember the torque of the trolley buses. We have steep hills and they climbed the hills like they were flat roads. The diesel buses wheeze and gasp and roar to get to the top.. especially when they're full. You think they're going to blow a gasket every time..

    versus ...whoosh! You're up the hill. Mind you, the street lamps for a block around dimmed when that happened, but so what!?
     
  5. HillCountryFun

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    To the OP, very interesting, thanks for posting!!

    So, I'm not sure how much of my inferring is accurate given the limited data in the article, but if 5 minutes is a full charge and assuming that 600KW is also used during that 5 minute recharge then the Bus Pack is about 50KWh.

    Also, using 600KW on a 50KWh pack would be 600/50 = 12C in terms of charging rate. That is absolutely amazing!

    My suspicion is that 600KW is not used during the 5 minute recharge just based on how we see Tesla tapering their charging rate. IF it runs at half that power level then you end up with a 25KWh pack. Using that pack size, now your talking almost 25C charging rate, which is almost crazy!

    However, it is only for 15 seconds. Which makes me wonder if Tesla could use a high power pulse like this in conjunction with it's standard tapering. Maybe watching the temperature of the pack closely, periodically pulse the pack with very high power for 15 to 30 seconds. Such an approach might help reduce SuperCharging time closer to an ICE refill.

    Very interesting tech indeed!
     
  6. scottm

    scottm Active Member

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    This sounds more capacitor-like kind of charging than chemical battery storage... man, it would be so cool to see these worlds combine.

    Can you imagine having a "capacitor cache" front ending a battery? That's so Silicon Valley. Ordering a bigger capacitor cache would be an available option, and like adding a turbo charger to an ICE. You could say, "my EV has a turbo charger".. and it would make sense!

    Tech: Rapid-charge batteries could last 20 years
     
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  7. cpa

    cpa Member

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    Slightly off topic, but since the door was opened to coulombs. . .

    I understand that a coulomb has to do with amps per second or some such. If I understand correctly, it is a measurement of the quantity of electrons (a la Avogadro's number for molecules in a mole.)

    So, recently my son had to undergo I-131 therapy. The information that was presented to me mentioned millicuries and coulombs. The decay is beta.

    So, how does the coulomb that all you EEs describe about charging and discharging relate to the coulomb with radioactive decay?

    Thank you, inquiring minds want to know!
     
  8. lklundin

    lklundin Member

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    #8 lklundin, Aug 10, 2016
    Last edited: Aug 10, 2016
    The bus would need about 170 kg of very good supercapacitors (that's an actual word) taking up about 0.3 m^3 of space to store the mentioned 2.5 kWh. Feasible for a bus, I guess.

    Yes, I think it could make sense - for regenerative braking.

    With a bank of supercapacitors, the vehicle would be able to momentarily absorb as much power as the motor(s) can deliver while braking, without charging the battery, and then afterwards delivery it back, also at the same maximum power, again without involving the battery.

    That would be very handy on the Autobahn, when one has to first brake hard because some inattentive driver pulls out in front of you, and then accelerate again, when that driver pulls into a slower lane again.

    For example: The total change in kinetic energy when slowing a 2 ton car from 200 km/h to 100 km/h is about 0.6 kWh, which is what 80 liters of supercapacitors (40 kg) can store.

    With regenerative braking like that some other changes may be necessary, like maybe activating the brake lights...
     
  9. Electric700

    Electric700 Member

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    I support faster charging and wouldn't be surprised if we see 1 MW (1000 KW) Superchargers at some point in the future. I know, 1 MW presents technical challenges, but wouldn't it be great to get a 0 -> 90%+ charge in just a few minutes?
     
  10. lklundin

    lklundin Member

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    "Listen up, BEV fans:

    All those who do _not_ support faster charging, please raise your hands!"

    Anyone?"

    Since a 1 MW supercharger does not currently exist one can assume it is hard to make one. One can also observe that Tesla has managed to increment SC charging power over the years.

    Is there something more specific behind the above 1 MW SC expectation?
     
  11. ebyard

    ebyard Member

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    All employees of ExxonMobil, BP, Shell etc just raised their hands....

    Seriously though; battery tech is important but equally so is recharge speed. I hope people are tipping money into research for this, as only when you get a car that can recharge quicker than it takes to fill a tank with fuel, will we see proper widespread adoption of EVs.

    In the meantime, it's up to us EV owners to just keep spreading the word, offering a ride in the car, and people will see the benefits.

    Then its up to power grids to scale in order to meet the demand. Your baseload generation requirements just went north.......! Though I guess if oil refineries reduce, that should help considerably.
     
  12. aesculus

    aesculus Still Trying to Figure this All Out

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    And SF bought all the ancient ones around the country and uses them daily. They are always packed.

    Oddly back in the 1970's SF was thinking of pulling these and the cable cars. The world went nuts when they announced the plans to pull the cable cars since they were so iconic to SF. So SF did the opposite and embraced the electric and cable old tech. Too bad they are not doing more of it. The recent mini dig to get Muni into Chinatown is an example of the wrong way to do it IMHO.
     
  13. gavine

    gavine Petrol Head turned EV Enthusiast

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    Disney needs to upgrade their parking lot people transporters (trams) to electric. Those diesels are loud and extremely smelly for the passengers. They only drive around the parking lot so a perfect fit for battery-electric. It takes 5 minutes for all of the people to embark so they can charge at each stop.
     
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  14. deonb

    deonb Active Member

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    The 5 minute recharge runs at 200 kW, not 600 kW:
    Flash charging | ABB

    But even with that, it's still 12C to charge it in 5 minutes, but 200kW @ 5 minutes implies a 16kWh battery. So either:

    a) ABB knows something about Lithium battery chemistry that neither Panasonic nor Tesla knows.
    b) ABB abuses the batteries and won't mind if they die in a year.
    c) The batteries are not all that small, and 5 minutes is not really a full recharge. I suspect it's this. Let's say it's a 60 kWh battery that they keep between 25% and 50% levels. So then a 200 kW will charge it at 3C between 25% and 50%. And then if you do 600 kW to it for 15 seconds, it's 10C.

    Which is still fast (and MUCH faster than Tesla will allow even at regen), but it's not quite as ludicrous.

    It will leave half the pack always unused, but a 60 kWh pack in the context of the price of a bus is nothing.
     
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  15. Electric700

    Electric700 Member

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    According to my rough calculations, 1 MW should allow charging to complete in approximately 5 minutes for the Model S 85. 2 MW would allow the charge to complete in about 2 minutes, which is of course better, but you have double the power requirement.

    Some technical challenges are cooling, energy storage at the Supercharger (perhaps with supercapacitor assistance), ensuring battery health is maintained, and designing with the right wire size.
     
  16. WannabeOwner

    WannabeOwner Member

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    Or half the number of stalls perhaps?
     
  17. Tucker48

    Tucker48 Member

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    UM YES. I am a huge fan and I'm actually not sure why they haven't considered this (if they haven't). Hoping the futurism didn't die with Walt, and a Tesla partnership would be exactly in line with their past operations (partnering with innovating companies). It would also be a really cool promotional opportunity for Tesla who does not advertise for not only a worldwide audience but an intangible vote of confidence for all those who think it's too scary. If DISNEY believes in it... :)
     
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  18. ItsNotAboutTheMoney

    ItsNotAboutTheMoney Active Member

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    A coulomb (named after Mr Coulomb) (C) is a unit of electric charge. It's the amount of charge transported by 1 ampere in 1 second. So, 1A = 1C/s. (I = Q/t)

    Beta particle - Wikipedia, the free encyclopedia

    Beta radiation is high-energy electron or positron, so the coulombs represent the total charge from those particles*.

    * Or waves. Depending on your view.
     
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  19. cpa

    cpa Member

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    And, I thank you, Money. So, the sum total of all the electrons vacating the nucleus (as 131-I-53 decays into 131-Xe-54) can be quantified in coulombs.
     
  20. deonb

    deonb Active Member

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    FTFY

    Lithium batteries that want to live long take 20 minutes to charge to 50%, 40 minutes to 80% and 80 minutes to 100%. Doesn't matter how big or small the battery is - that's how long the individual cells take.

    The size of the Supercharger is not the constraint here. You either take that long, or you damage the battery.

    The typical Supercharger location already has 500+ KW available that they split into 4 or more ways. If there was any way Tesla could have just hooked that up to one car and charged the battery to full in 10 minutes they would have - game over ICE. Even if the cost was another $10k per car in bigger cables, connectors etc.

    But that's not where the constraint lies - it's with the lowly individual lithium cell.
     
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