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Warning "Battery level exceeds charge limit"

Discussion in 'Model S: Battery & Charging' started by Patrick W, Oct 28, 2015.

  1. Patrick W

    Patrick W Member

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    I returned to the supercharger shortly after the car had finished charging last evening and saw a message on the display reading "Battery level exceeds charge limit".

    The limit is set to 90% and as far as I could tell that was the level it was charged to (I get around 238 or 239 on a typical 90% charge and the car was showing 239).

    I've only had the car a few months and this is the first time I've seen that warning.

    The warning does not appear to be in the owner's manual.

    Has anyone here seen that warning and/or know what it means?
     
  2. scaesare

    scaesare Active Member

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    Battery state of charge (SoC), is a somewhat of a moving target in terms of being able to accuarately measure at any one point in time. It roughly correlates with voltage at a given temperature, etc...

    So. it's possible that the car can measure the voltage at one point, and correlate it to a 90% SoC. Some time later the voltage could drift upward slightly as a result of temp change or other factors, and the SoC could appear at 91%. This is the same reason occasionally your home charging will stop at a given rated mileage and a bit later it can actually be reported as greater range by a mile or two.

    The warning should be nothing to worry about.
     
  3. ecarfan

    ecarfan Well-Known Member

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    But why would Tesla provide a user warning like that? It's confusing, and likely unnecessarily alarming.
     
  4. scaesare

    scaesare Active Member

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    Yeah, not sure what we are supposed to really do with that info. I got it once charging at home.

    I kind of suspect that it may be there to inform you why the car won't start charging if you manually try to initiate such, and didn't realize your charge slider was below your current SoC, or some such. Basically a polite "Here's why the car won't do that" kind of message.

    It may be triggering in this case somewhat as a byproduct of the existing logic... but that's just a guess.
     
  5. mknox

    mknox Well-Known Member

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    No kidding! It makes it sound like the battery is dangerously overcharged!

    Maybe, but I've plugged my car in lots of times with the slider below my current SOC (going away on vacation, for example) and never seen anything like that. The charge port just lights up steady green to indicate the battery is at or above the setpoint and that's all.
     
  6. scaesare

    scaesare Active Member

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    It's definitely a SWAG on my part.... did you try to initiate charging, or just plug it in? (Or will it even let you try... I don't remember.. I should test that I guess...)
     
  7. SW2Fiddler

    SW2Fiddler Bannd Member

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    #7 SW2Fiddler, Oct 28, 2015
    Last edited: Oct 28, 2015

    OP said it was a "message on the display" -- [of course I can't tell for sure but I think] the word WARNING was added by the OP, in the thread title. And used as a description later in the post, not quoting their car.

    Central display status messages have to be short and concise.
    There's not enough room to put something like, "Hey, um, nothing to worry about but I've recalculated and your battery actually has more charge than you asked for. Just wanted you to know..."
     
  8. mknox

    mknox Well-Known Member

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    I don't think I've actually tried to initiate charging, but I don't think the OP did either (just returned to the car and saw the message). Often, if I'm going to be away for a period of time, I'll drop the slider down to (usually) 60%, plug in and leave. The car may currently be at 70 or 80%. Depending how long I'm away, the car may eventually drift down to some value below the setpoint and a charge cycle will initiate.
     
  9. scaesare

    scaesare Active Member

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    I don't think the OP did either. As I said in my earlier post, I think that may be why Tesla included the message in the car's logic, but:

     
  10. Patrick W

    Patrick W Member

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    Thanks for all the replies. Looks like I've nothing to worry about.

    FWIW I don't think the word "Warning" was in my original post. But for sure it was not on the text on the display. Rather the display showed one of those yellow triangles with an exclamation mark in it followed by text reading "Battery level exceeds charge limit".
     
  11. Todd Burch

    Todd Burch Electron Pilot

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    Because if you didn't notice it, you might leave the car sitting there, plugged into a Supercharger and doing nothing, which might mean someone else might not be able to charge. It's worthy of a message on the display IMHO, although it could be worded a little more clearly, something like:

    "Battery level already above your charge limit. No charging will occur."
     
  12. mknox

    mknox Well-Known Member

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    Ummm... isn't the yellow triangle with the exclamation point the symbol for "Warning"?

    From Google:

    10-29-2015 10-25-25 AM.jpg
     
  13. Gwgan

    Gwgan Almost a wagon

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    Bump. I saw this today. Upped the charge limit a tiny bit, charging started, and the error went away. I also wonder why bother with such a message unless there is danger?
    1.jpg
    btw, the yellow triangle was throbbing.
     

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