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12v battery

Discussion in 'Model S: Battery & Charging' started by P85DBeast, Apr 1, 2015.

  1. P85DBeast

    P85DBeast 3 Model S!! 85D,P85D,P100D

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    as anybody's 12v batter pack failed yet becuase mines hasn't I just want to know the symptoms before it happens becuase I drive a lot and don't want to be parked somewhere waiting for tesla service tow truck to arrive just asking I really want to know!!!!
     
  2. spaceballs

    spaceballs Member

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    if your that worried, just buy an small battery jump starer and keep in in the frunk.
     
  3. FatSal

    FatSal Member

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    Dec 28, 2012
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    Cleveland, OH
    Tesla actually called me and said they had been monitoring my car and noticed signs that the battery would need to be replaced soon. They said to schedule an appointment and I could continue driving the car. About 1 week later I received a notification in the car to replace the battery soon. I replaced the battery about 3 days later. Never had any other issues.
     
  4. AmpedRealtor

    AmpedRealtor Active Member

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    The car is supposed to give you an alert if the battery is close to needing replacement.

    Prior to receiving the alert, I noticed the car didn't sleep much. It seemed to be awake more than it was asleep. The car wakes itself up to top off the 12v battery. If the 12v is not holding charge well, the car will be waking up more often to charge it. That is your first indication that something may be afoot.
     
  5. dirkhh

    dirkhh Middle-aged Member

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    Tesla changed the way the car monitors the health of the 12V battery about a year ago. The car now shows a warning as soon as there is concern about the health of your 12V battery.
     
  6. jepicken

    jepicken VIN: 80322

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    Pardon the dumb question, but how can you tell how much the car is sleeping?
     
  7. SabrToothSqrl

    SabrToothSqrl Active Member

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    I hate it when my car can't sleep. ;) It's up all night pacing the garage.
     
  8. apacheguy

    apacheguy Sig 255, VIN 320

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    Everyone has their favorite method. I use my own code to monitor range and SOC in 30 min increments:

    Web Based Model S Interface
     
  9. brianman

    brianman Burrito Founder

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    Yah, the tire wear is killer.
     
  10. woof

    woof Model S #P683 Blue 85 kWh

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    Mine snores.
     
  11. sorka

    sorka Active Member

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    Everyone is going to need to replace their battery frequently. If you leave the car in always connected mode, the battery will be half way drained 6 times a day and recharged six times a day by the inverter when it's just sitting there whether it's plugged into shore power or not.

    Lead acid batteries due to not tolerate constantly being discharged.
     
  12. dirkhh

    dirkhh Middle-aged Member

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    I'm curious about "6 times a day". It appears that the 12V battery is a meager 35Ah unit, so 420Wh capacity, trying to keep it healthy by only half-cycling it would give us 210Wh usable. Your assumption of 6 cycles a day means you assume the car is consuming about 1.2kWh a day for the connected mode or 50W. Given that a typical phone can stay connected on less than 2W (and usually on even less than that) I'm not quite sure why you assume a 50W load.
    I'm not saying you are wrong, I'm just curious how you got there.
     
  13. mibaro2

    mibaro2 Member

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    And it is strange that Tesla encourages you to have "always stay connected" checked, and energy savings off. Whenever I take my car to the SC, they switch it to be like that. I use to switch it back, but now appreciate the car waking more quickly.

    But back to the 12v getting drained more often with always connected checked...why would Tesla encourage this if it will cause the 12v battery to die more frequently?
    I also wonder how the cold affects the 12v battery...maybe I should get mine replaced after the winter we had ( or are still having..it is snowing right now !). It was a bitterly cold winter.
     
  14. AmpedRealtor

    AmpedRealtor Active Member

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    When I launch VisibleTesla, it tells me if the car is sleeping and requires a confirmation to wake it up. Prior to replacing the 12v, more times than not, when I checked on the car using VisibleTesla the car was not asleep and the application logged-in immediately. After replacing the 12v, checking on the car regularly using VisibleTesla results in the "car is asleep" message 90% of the time.
     
  15. Steve Watkins

    Steve Watkins Member

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    failed without warning day before yesterday; usually will either get warning or call from Tesla that it is about to go out; last time went out while using "loaner" pack while my battery pack being "reconditioned" Jan. 24, 2015; 68,900 miles (approx.) currently; no explanation so far; WARNING: if using loaner pack, rated range is not accurate until pack has been cycled through a few times (I was told) but I have not tested it out since car dying with 11 miles rated range 3.5 hours from home
     

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