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Miles went from 15 to 0 in less than hour, while parked!

Discussion in 'Model X' started by tslaEbay, Nov 28, 2019.

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  1. tslaEbay

    tslaEbay Member

    Joined:
    Jan 29, 2017
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    48
    Location:
    san ramon, ca
    Hi,

    Did anybody experience this?
    Recently..I reached home after a long commute at around 8 PM with only 15 miles left.
    I plugged the charging cable but it is scheduled to charge only at 11 PM as the low electric rates only kick in at that time.
    When I checked my app around at 9 PM..I see the miles 0!!
    Does this mean..I really did not have 15 miles left or BMS drained those 15 miles in an hour?
    It was a cold/rainy night in Bay area.

    Thanks in advance
     
  2. LukasSwan

    LukasSwan Member

    Joined:
    Nov 18, 2016
    Messages:
    139
    Location:
    Halifax
    I saw some very weird stuff in last week too.
    Parked in evening with 29%. Came back to 18% in morning.

    Next day. Charges to 85%. Drove 5 km and parked at 83%. Went in store. Came out 1 hour later. Dash said 88%.

    Must be latest software.
     
  3. Yoitskenn

    Yoitskenn Member

    Joined:
    Mar 24, 2019
    Messages:
    379
    Location:
    Vallejo, California
    I had a similar weird occurrence. Supercharged to 90% at 208. Drove Home and parked at 205. Got back in the car an hour later and it was reading 212.
     
  4. gangzoom

    gangzoom Active Member

    Joined:
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    Messages:
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    Location:
    Uk
    The BMS is simply 'guessing' the ture SOC all the time, and with cold weather it gets it wrong sometimes.

    Looking at our car, the car actually shows TWO DIFFERENT SOC 'guesses'. With nearly a 4% difference between the two values which would account for easily 10miles+ changes in reported range.

    The only way the BMS really knows which SOC is correct would be to drive the car to empty till it stops.

    [​IMG]
     
  5. tslaEbay

    tslaEbay Member

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    Location:
    san ramon, ca
    Thanks @gangzoom....what tool gives all these details?
    It is good to know that there is some energy buffer.
    So..in conclusion...when the car says 15 miles to go...we can't really trust it.
    What does "SOC UI" mean?
     
  6. Pilot7478

    Pilot7478 Member

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    Location:
    Toronto, ON Canada
    Since I got v10 I've noticed when I come home with 15% or less the car will loose exactly 8% during next hour or so just sitting in the garage even if the temperature is 10-15 C (not very cold). After that, I would charge to 80 at night and next day it will slowly get back the lost percentages (like I would park somewhere at 75 and come back to 77). Today I've charged to 70, the app reported "stopped charging at 70" and a few hours later I've found it reporting 74% (the was sitting in the garage). Glad it's not something wrong with my battery as people reporting a similar problem in this thread...
     
  7. tslaEbay

    tslaEbay Member

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    Jan 29, 2017
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    Location:
    san ramon, ca
    @Pilot7478...yes. same thing happened to me. That night I charged to 121 miles and next day I drove for 11 miles (at EPA rate) but it still showed around 117 miles. Something wrong with the latest SW, I guess.
     
  8. Pilot7478

    Pilot7478 Member

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    Location:
    Toronto, ON Canada
    This story continues today (next day). After getting 74% yesterday (see my post above) I've found it at 79% today with the car still sitting in the garage! Temperature in the garage is 11 C. S
    To sum up: set it to charge to 70% on Friday night, at night got app notification "charging complete at 70%", on Saturday found the car reporting 74%, on Sunday car reporting 79%. No charging.
    2019.36.2.2
     
  9. gangzoom

    gangzoom Active Member

    Joined:
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    Uk
    I think its more the BMS sometimes genuinely doesnt know what the SOC is.

    This is our car today, same software as last weekend, yet reporting over 1 kWh less usable energy, and the difference between SOC UI and SOC MIN is also different. Clearly working out true SOC is black magic!!

    [​IMG]
     

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