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Do I have to reset the charging amps every time I connect to a new power source?

Discussion in 'Model S: Battery & Charging' started by Msolomi, Jul 11, 2013.

  1. Msolomi

    Msolomi Member

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    May 25, 2013
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    Location:
    Atlanta
    In other words, if at home I'm charging with a HPWC at 60 amp and then I go to a hotel that has a 240v/40 am outlet, do I need to reset my charging rate in the car before moving from 60amp to 40 amps or will the car detect it automatically? Thanks for your responses.
     
  2. mitch672

    mitch672 Active Member

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    Location:
    Stoughton, MA
    Each location you charge at is remembered by its GPS coordinates, so it will remember the last charging power level you used at each location.
     
  3. Msolomi

    Msolomi Member

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    So for each NEW location all I do is plugged in without changing the amps in the car?
     
  4. TurboFroggy

    TurboFroggy Member

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    Everett, WA
    Yes. The charging station your plugged into reports the available amps to the car and that is how the amps are negotiated. It is all part of the SAE J1772 Spec: http://en.wikipedia.org/wiki/SAE_J1772
    For example, public charging stations for the most part 30 amps, your car will try to draw 30 amps automatically and no more.
    Your UMC reports 40 amps available, HPWC reports 80. However due to the issue with the fuses in the HPWC the software will prompt you if you try to charge more than 60 amps.
     
  5. stopcrazypp

    stopcrazypp Well-Known Member

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    If I understood correctly, you are talking about two different situations. One is HPWC at home (no UMC involved), the other is using the UMC. When using the HPWC or any public J1772 charging station (EVSE), the EVSE will report the available power and the car will limit current automatically.

    When using the UMC, the UMC will report lower available power based on the adapter you connect. The only time you have to dial down current manually is when you know the circuit can't handle the full continuous power of the adapter on the UMC. For example some people choose to use the 14-50 adapter on a 14-30 socket (by removing the neutral pin on the 14-50 adapter) and you would have to dial down the current manually in that case to 24 amps.
     
  6. Msolomi

    Msolomi Member

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    Ok. Thanks for all your responses. If we could now find out from tesla if the HPWC can handle 80 amps as I got an 100 amp installed at home.
     

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