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How long will the battery last if cabin light is left on?

Discussion in 'Off Topic' started by Kitt, May 19, 2014.

  1. Kitt

    Kitt Member

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    You see ICE cars often cant start because you have left cabin light on all the night.
    Now i have wondered how long a Model S can provide energy to it
    If the cabin light is a 3W LED then boy...... you can do the calculation yourself.
    Self discharging probably will be faster. haha
     
  2. NEWDL

    NEWDL R#350 R#1323 Sig23 8136

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    It wouldn't use the TESLA pack for the light... It would draw off the 12v. It would still take a very long time, but not as long as the big pack...
     
  3. Vger

    Vger Active Member

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    Actually, the big pack will charge the 12V battery as needed, so it would take weeks, if not months for a few LEDs to drain the car!
     
  4. Kitt

    Kitt Member

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    excuse me, which 12 V battery pack?
     
  5. Chipper

    Chipper Active Member

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    Just like an ICE the Tesla has a 12 volt battery under the hood in the back of the frunk under the plastic panel. Just like ICE's this battery is subject to discharge when a door is left open or a light is left turned on.

    @VGER--Do we know for a fact that the main pack will recharge the 12 volt??? If so, why were there so many problems with the 12 volt batteries in the earlier models?
     
  6. stevezzzz

    stevezzzz R;SigS;P85D;SigX

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    There's small 12V battery forward of the passenger footwell that's used to power computers and accessories. It's recharged as needed from the main traction pack, so no need to worry about leaving the interior lights on: back of the envelope, 85kWh divided by, say, 8.5W gives you 85,000 hours to remember to turn off the lights... :biggrin:

    In reality the car draws significantly more than that even when it's sleeping so, really, the dome lights are the least of your concerns if you have to leave the car unplugged for a period longer than a few weeks.
     
  7. FlasherZ

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

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    There were several issues that needed to be rectified.

    First, Tesla ended up with a batch of batteries that didn't last all that long for the purposes they served. Replacement fixed that.

    Second, Tesla found that the DC-DC converter's firmware was refusing to charge the 12V battery in certain cases (I believe high-temperature outdoor locations). Service centers flashed new firmware as part of a TSB.

    I think there was something else having to do with charging thresholds as well that was rectified through software.

    I haven't seen a 12V complaint in a long time.
     
  8. Doug_G

    Doug_G Lead Moderator

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    It would last months.

    Kitt, what is your purpose here? You seem to be always trying to find fault with the car, but in bizarre ways.
     
  9. pgiralt

    pgiralt Active Member

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    I don't think you can leave the light on anyway. Pretty sure the car turns off the light automatically even if its been manually turned on.
     
  10. Kitt

    Kitt Member

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    No, i was just amazed by this thought. No intend to make Tesla bad or so. OMG, no.
    I mean you are now carrying basically a super awesome MEga battery with you. Now you can cook coffee or what else......anything.
    What a pity that the Model S doesnt have a 230V outlet. LOL
    ALso i like the fact that BEVs are super awesome party cars. Crank up the volume and make a party in the park.
     
  11. Alfred

    Alfred Member

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    For safety reasons the high voltage pack (375V or so) is automatically cut off under some circumstances, similar to the interruptors on petrol lines in conventional cars. The 12V battery serves then to secure continued support of essential systems, such as emergency lights. It was certainly also cost efficient to have a 12V system to allow the use of common car parts (lights, wipers, sound etc.).
     
  12. NigelM

    NigelM Recovering Member

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    The Model S is smart; once you exit the car and lock the doors (or they are on auto-lock) the lights fade to off, even if you you set them to permanently on.

    BTW, the light in the refrigerator also goes off when you close the door.
     
  13. dsm363

    dsm363 Roadster + Sig Model S

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    How do you know this?:)


    Why exactly are we worried about leaving a light on in the Model S?
     
  14. Btrflyl8e

    Btrflyl8e Active Member

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    Relax, Kitt was just musing about how crazy long it would take in a Model S, vs overnight in an ICE, most likely.
     
  15. NigelM

    NigelM Recovering Member

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    Exactly. It's digital vs analogue and analogue cars suck.
     
  16. Btrflyl8e

    Btrflyl8e Active Member

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  17. Kitt

    Kitt Member

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    This thread wasnt about making people worried.
    Just a fun assumption. GLorifying the great holy battery BEVs carry on bord. :)
    By the way the Model S 'could' carry around a big refrigerator.
    Here in Europe an refrigerator energy efficiency class A+++(now we have laws for that :) ) with 100 l volume uses around 70kwh/year.
    All it needs is a good insulation.
     
  18. Kerbs

    Kerbs Member

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    hehehe love it....
     
  19. AC1K

    AC1K Member

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    #19 AC1K, May 20, 2014
    Last edited: May 20, 2014
    if you want to do a gross exaggeration its

    85kWh = 85,000 Wh (gotta make the units the same)

    85,000Wh ÷ 3W = 28,333 h ( the unit W cancels out leaving you with hours)

    this equates to 1180 days or several years.

    EDIT: oops copied the wrong number, i was calculating something regarding torque in another thread.
     
  20. Kitt

    Kitt Member

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    a year has 8760 hrs.
     

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