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About the HPWC and dual on board chargers?

Discussion in 'Charging Standards and Infrastructure' started by sp4rk, Nov 29, 2012.

  1. sp4rk

    sp4rk Banned

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    I am a bit confused about these charging options. And when I talked to Tesla this morning to finalize my order, they seemed as confused.

    I told her I wanted to INCLUDE the twin chargers in my S.

    So she went to tack on the HPWC.

    My plan is to sell my current house soon. Not make electrical changes now. Currently it has a wall charger for my Leaf (to be "traded in") on a 220v 1773 plug.

    I understand you can charge the S using J1772 albeit a lot a slower using Tesla's adapter.

    Even though it has the twin chargers, it will still charge, correct?

    Then, later, I can add a HPWC to my new house

    Maybe more expensive then ... but ...
     
  2. JakeP

    JakeP S P4996 / X P6028

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    Yes, there is no harm having the second charger, even if it goes unused. Though you might benefit from buying the HPWC now...who knows what price it will have if sold separately.
     
  3. ibcs

    ibcs Member

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    Leaf charger will give you 10-12 miles per hour of charge.
     
  4. brianman

    brianman Burrito Founder

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    The twin chargers also help if you're using a Tesla Roadster HPC like, say, at a Tesla store near you. ;)
     
  5. Al Sherman

    Al Sherman It's about THIS car.

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    It's a little off topic but: for me it seems like a no brainer to get the twin chargers and the HPWC if the money thing isn't an issue. Everyone I speak with tells me I don't need it. When I tell them I drive like an old man, and I can't remember the last time I drove my Prius (have had it 5 years) more than 200 miles they all say; you don't need it. But I WANT it. So I'm getting it. My only question may be very stupid but hey it is what it is. My guess is the HPWC is not any less efficient? Kwh are Kwh's right? Other than the upfront cost being much higher it'll use the same amount of Kw's even though I'll rarely have to charge the Model S from close to zero. Correct?
     
  6. TEG

    TEG TMC Moderator

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    At some point, charging too fast can be hard on the battery. But that would be up in the "Supercharger" and beyond sort of charge rates.
    Also, at some point, very slow charging (e.g., off of [email protected]) can be inefficient because it is still supporting some "charging overhead base load" (like running cooling pumps, and charging computers.) so less % of the input energy actually makes it into the battery.

    IMHO, 240V charging at 24-70amps is all "in the sweet spot" in terms of good efficiency and not particularly harmful to the battery.
    So, assuming the cost didn't bother you, no, I don't think there is a reason to shy away from the twin chargers. It could come in handy on a road trip if you couldn't find a supercharger but found a 70amp J1772, Roadster HPC, or friend with a HPWC.

    With that said, the 2nd charger probably does add a small amount of weight to the vehicle and could therefore affect performance ever so slightly...
     
  7. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    The difference is that a higher rate of charge heats the battery more and requires the cooling system be run to keep the battery cool so there is some energy used for that rather than stored. In too low a charge rate there are more transmission losses. The reasons for getting twin chargers are:

    1. You have an HPWC.

    2. There are or will be ESVEs greater than 50 amps installed and there is no close by Supercharger.

    3. Cars with twin chargers will perhaps bring a higher price because they have more flexible charging options.

    The reasons to get an HPWC are:

    1. You frequently use a fair percentage of your range on most days and you need to charge up quickly for that unexpected evening trip.

    2. You want to be able to charge other folk's Model S as a courtesy until there is a convenient Supercharger.

    3. You need the extra cable length 25' vs. 18' for the UMC.

    4. You want one because it looks cool or has a convenient place to hang the cord.
     
  8. wstuff

    wstuff Junior Member

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    I am currently having the electric done in my garage in anticipation , i have opted for twin chargers. i also don't think I will need the HPWC, but 62 miles per hr of charge is intriguing. Except for my bus I will be off fossil fuels and as the S will be my only transportation I think taking advantage of the 100 amp line is a no brainer, should I return from a trip and find I have a low SOC I will feel very confident that within a few hrs I will be good to go anywhere. I also think that with the possibility of the superchargers upgrading to 120 amps in the future twin chargers will be a real asset and i believe a better resale than a performance model. I am opting for the non performance model ( I wish i could think of another explanation) THERE IS NOTHING NON PERFORMANCE ABOUT IT. On my test drive in Menlo Park, I punched the AMP pedal half way and that was plenty for me. I don't know what I would do with a performance model. All in to suit my needs I will be 85kw, blue, tan, pano, tech and sound, air, twin chargers and HPWC, and I think i will opt for aftermarket turbine 19 inch wheel b?c I do like the look of them, maybe I can sell my new 19 inch wheels to someone to mount snow tires as I don't anticipate ever needing them.

    - - - Updated - - -

    I also meant to mention that I understand TEGS point, but after the inovation I have seen in TESLA, I have complete confidence that with the battery gaurantee and the controls i will feel very safe in charging with 100 amps and the HWPC.
     
  9. TXjak

    TXjak Owner/Investor/Advocate

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    You are confusing two different modes of charging. The Superchargers use Direct Current (DC) and the twin chargers use Alternating Current (AC). So there is no connection between supercharging and the twin chargers. The twin chargers will give you up to 62 mph with a 100 amp 240v AC circuit to your HPWC. The Supercharger will give you 300 mph at the present time.
     
  10. wstuff

    wstuff Junior Member

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    hank you, I stand informed
     

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