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Charging with the car 'on'?

Discussion in 'Model S: Battery & Charging' started by elecblue, Aug 19, 2012.

  1. elecblue

    elecblue Member

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    Does anyone know if you can charge the Model S while it is on? Let's say you're on a road trip and need to plug into a 50-amp service outlet at an RV park, and would like to take a nap in the car while it's charging. But, it's a little chilly outside so you want to run the cabin heater. Can this be done while charging the car?
     
  2. Doug_G

    Doug_G Lead Moderator

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    You should ask Tesla. The Roadster has to be "off" while charging, but the Model S is supposed to be able to maintain cabin temperature when it's parked.
     
  3. SCW-Greg

    SCW-Greg Active Member

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    Great question for the FAQ.
     
  4. Norbert

    Norbert TSLA will win

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    Hopefully includes ventilation. And maybe music. Maybe even a wake-up-(music-)alarm when a) charging has finished, or b) for a certain time.
     
  5. NigelM

    NigelM Recovering Member

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    The Roadster has a single A/C and can't handle maintaining temperatures in two places at once, so it has to switch between power train and cabin. Model S has twin compressors so in theory it should be able to handle both.

    Operating any Model S features while charging will be drawing from the battery you're charging, so however small the draw you will also be extending your charge time.
     
  6. doug

    doug Administrator / Head Moderator

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    Hopefully it would be drawing from the grid and skipping a detour to the battery.
     
  7. W.Petefish

    W.Petefish Active Member

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    From what I understand, it can be done. BUT as suggested it draws from the battery pack, thusly extending your charge time.
     
  8. widodh

    widodh Model S R231 EU

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    How would you do that?

    The charger is delivering X amps which goes into the battery. But if you dray Y amps for running the car you're charge will be: X - Y = charge
     
  9. markwj

    markwj Moderator, Asia Pacific

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    In the roadster, charging and driving is from the same PEM, right? Charging, the PEM runs AC -> DC. Driving, the PEM runs DC -> AC. But, only one way at one time. Hence those discussions about towing a generator to charge while you drive won't work, and the roadster won't turn on while the charge port is open.

    Now, again in the roadster, 12V accessory power comes from a 12V converter in the ESS, and that is live while charging (otherwise VMS wold have issues). HVAC operates from the 400V output of the ESS, and is converted (to what?) by the orange box in the front trunk. The roadster can run the HVAC during charging, but can't direct the cool to the cabin, but I suspect only because the A/C can't be turned on without the car on. No electrical reason why not (unlike driving and charging).

    So, what's the arrangement with the Model S? Sounds like the PEM and charger are two separate devices.
     
  10. NigelM

    NigelM Recovering Member

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    The Roadster actually diverts the HVAC output according to thermal control limits; that's why stopping at long traffic lights is such a PITA in the Florida summer. Model S has two compressors, one for the cabin and one for the powertrain so it's not diverting HVAC output back and forth.

    OT, the Roadster HVAC could never manage cabin and powertrain temperatures simultaneously; in theory Model S HVAC(s) could.
     
  11. mnx

    mnx 2013 P85

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    OT: "We just completed our hot weather endurance testing, we had the Model S out in Death Valley. [During] the hottest portion of the day, we wanted to see if the Model S could maintain cabin temperature while going at 70 mph up an incline in Death Valley. Yes it can. I'll tell you what couldn't: the tow truck that we brought.

    Read more: http://www.automobilemag.com/features/news/1208_q_and_a_elon_musk_ceo_tesla/viewall.html#ixzz246GUm6OA"
     
  12. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Of course, the real question is: How much longer will it take to charge? 5 minutes? 15 minutes? 30 minutes? If you're on a trip and charging at an RV park for 8 hours (240 miles worth of charging) that's not going to impact your arrival time significantly.
     
  13. doug

    doug Administrator / Head Moderator

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    That's fine. What I meant is skipping charge/discharge in the battery.
     
  14. markwj

    markwj Moderator, Asia Pacific

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    HVAC in the roadster is somewhere around 1 to 2 kW (educated guess). Heater probably less,

    So, it depends what voltage and current you are charging at. 240V 32A is 7.68kW, so expect perhaps 13% to 26% for cooling. Estimates include conversion losses. At 220V/13A it is brutal, and unworkable at 110V/10A.

    You might be more comfortable, but will end up staying longer.
     
  15. 4sevens.com

    4sevens.com Member

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    I'm curious about the answer to this question for another reason - said there is a need to make a 1000+ mile road trip. What the possibility of putting a generator in the frunk just for the road trip - so the generator is running all the time supplying power to the car... charging or supply power to the powertrain....
     
  16. TEG

    TEG TMC Moderator

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    FWIW, I can turn the Nissan LEAF "on" (but it stays locked in park) while charging.
    I have sat in the car using the A/C & radio while quick charging.
     
  17. Robert.Boston

    Robert.Boston Model S VIN P01536

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    My lightly informed guess is that there's a difference between drawing current for auxiliary loads like HVAC vs driving the car. Putting a generator in the frunk generally seems like a seriously bad idea, considering the intake and exhaust issues. See "Fisker Fires".
     
  18. chmod a+wrx

    chmod a+wrx Member

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    Nice article.


    Thanks for posting!
     
  19. 4sevens.com

    4sevens.com Member

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    I'm just thinking about long distance enduro situations... maybe not the frunk... maybe the generator towed behind the car...
     
  20. elecblue

    elecblue Member

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    Good thoughts everyone - so how would I post the Q on the FAQ blog?

    Thanks!
     

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