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Pilot Current / charging error

Discussion in 'Model S: Battery & Charging' started by scaesare, May 3, 2014.

  1. scaesare

    scaesare Active Member

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    I noticed (via Visible Tesla) my car was only reporting a pilot current of 30A this morning... my HPWC is set for 40A. When I went out to the garage and looked, the dash said there was a "charging error" and the charge ring was blue. The car was charging, albeit at a reduced rate.

    I reseated the HPWC and all returned to normal

    It also so happens my car did a couple of extra charge port lock/unlock cycles when I plugged in my HPWC the other day.

    Coincidence and/or bad contact?

    What seems weird is the pilot current error. That's something driven by the duty cycle of the pilot signal, and wouldn't be subject to "reduced contact surface area" I'd imagine. I also have gotten a yellow ring if I had a bad cable insertion.

    If the car doesn't get pilot signal at all, does it assume 30A for a 240V input?
     
  2. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    It assumes 16A @ 240V from my experience and ring is generally yellow. Blue usually happens when the car isn't ready to charge but voltage is present -- while upgrading or on scheduled-charging hold.

    Could be bad contacts, I suppose. On my car, bad contacts generated a red-ring before it recovered and went green.

    Tesla can probably pull logs to figure out what went wrong.
     
  3. scaesare

    scaesare Active Member

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    Thanks FlasherZ... other folks who have also had the Charge Port Lock Behavior that I did also have seen current reduction... so it may be something that's a common failure mode...
     
  4. scaesare

    scaesare Active Member

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    Well, this is interesting... after having experienced the "30A drop" in charging current pretty consistently for a number months, I seem to have charged at 40A without issue for the week since I got 6.0...
     
  5. scaesare

    scaesare Active Member

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    And a week later, it's been at 40A consistently every night for my scheduled charge.

    However, the one time I opted to charge manually one morning, it again dropped to 30A. This despite Visible Tesla reporting that the pilot current from the HPWC was indeed still 40A

    This makes me wonder if the voltage fluctuation monitoring introduced on the 5.x+ firmware is kicking in? I generally don't have much more than about a 5% drop in line voltage when the car ramps up to 40A during the day (from ~242 to ~231). I don't know what that's like at night...

    Does anybody know what the voltage fluctaion threshold for reducing the charge current is?

    Is there any message when this happens? I twice got a "charging problem" message early on when the reduction happened, but never since.
     

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