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Stuck at 47A

Discussion in 'Model X: Battery & Charging' started by dailo, Sep 16, 2017.

  1. dailo

    dailo Member

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    Recently when charging at home I see that it only goes up to 47A. Not a huge deal, but curious why this recently changed. If I stop charging I can set the max to 48A but once charging starts it stops at 47A. Always show 47/48A in the app, but used to get 48/48 before. Has anyone else seen this?
     
  2. brkaus

    brkaus Active Member

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    What is the voltage showing?
     
  3. dailo

    dailo Member

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    Varies from 240 to 244. I have my HPWC set to 48 since the car can't charge any higher.
     
  4. brkaus

    brkaus Active Member

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    This is just a guess, but I think I recall reading the charger is limited in Watts and in amps. So when the voltage is on the high side, the current drops.

    240v @ 48a is the same power as 244v @ 47.2a

    But - simply a guess.

    Might try a ChargePoint that has lower voltage (many are 208) and see how many amps it will pull.
     
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  5. Rocky_H

    Rocky_H Active Member

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    People have seen similar 79 out of 80 on a wall connector for that same reason--voltage being a little high.
     
  6. AB4EJ

    AB4EJ Member

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    Sure would be nice to have more visibility into what our cars are doing when charging; or maybe some explanation about the algorithm being used by the system. I went to St. Louis this last weekend, and on a couple of the charging stops (at superchargers), charging rate would not exceed 57 kw (when I was the only person there); at others, it cranked up to 105 kw. (temperature related??) Could temperature also be a factor in the amount of power vehicles can take at home chargers? (seems far-fetched, but you never know)...
     
  7. Rocky_H

    Rocky_H Active Member

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    No, probably not. They are all very low as far as the battery is concerned. The connectors and cables, maybe... 40A and 80A are the maximum rating for the mobile connector and wall connector, so they can get pretty hot at those levels. However, I haven't heard of them throttling down the speed. They just...fail if they are too hot for too long and build up some kind of heat damage.
     
  8. Cowbell

    Cowbell Member

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    I see the 47A max rate at my location. The voltage does run a bit high here ~245 to 247. In the heat of the day with all the residential HVAC the voltage drops to the low 240's and I can get 48 A.
     
    • Informative x 2
  9. gavine

    gavine Petrol Head turned EV Enthusiast

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    Same here.
     
  10. ElectricHoo

    ElectricHoo Member

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    I have the same issue with my new wall charger--only pulls 47A, but voltage at 244-245V. Thanks for the useful and highly logical insight!
     
  11. gavine

    gavine Petrol Head turned EV Enthusiast

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    My charge today was at 250V briefly and the amps went down to 46.
     

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