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BMW ActiveE with severe RAMP (Range Anxiety ... )

Discussion in 'Electric Vehicles' started by sublimaze1, Oct 5, 2012.

  1. TEG

    TEG TMC Moderator

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    #2 TEG, Oct 5, 2012
    Last edited: Oct 5, 2012
    Some good info there, but I think he was off a bit with this statement:
    I think the terminology is a bit off there.

    For starters, I think when he says "Tesla charger" he means the Tesla HPC (EVSE) that he finds at "work" (I assume he works for Tesla), and in that case, the EVSE would be sending the ampacity signal towards the car, not the other way around.
    I think what he is really saying is "The Tesla HPC is able to provide up to 70A but my BMW is only charging using 30A."
    It looks like Phil at EVSEupgrade made him a custom box that goes from Roadster socket to J1772 plug.
    (Hey Bonnie, we have a picture of that 'unicorn' in the wild!):
    tbox.jpg
    I don't know what exactly is in that little gray box, I would guess it just passes through the ampacity signal straight from the Roadster socket side to the J1772 plug. So, it may actually be telling the BMW that 70A are available, but the BMW doesn't have a charger onboard that can charge at that rate, so it proceeds to just draw ~32A even though the signal says that more is available.

    (Further clarification - in the photo above he was charging from UMC, not HPC, and using the NEMA14-50 cable on the UMC, so the UMC was probably generating a 40A signal towards the J1772 adapter. In which case the BMW would be drawing ~32A when up to 40A was available...)
     

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