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Powerwall as Range Extender?

Discussion in 'Tesla Energy' started by Saghost, Jun 2, 2015.

  1. Saghost

    Saghost Active Member

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    One of the posters in the 70D-105D thread threw this idea out in passing, and I thought it might be worth more serious consideration.

    Generally when people talk about adding batteries to a modern EV, it just isn't practical - you have to match the ~400V output, and somehow deal with safely connecting it and with managing the power flow and heating/cooling.

    However, the Powerwall is different. It's already in the same voltage range, and packaged with a DC-DC converter and cooling system. The DC-DC converter is potentially an answer to both the safety and the power flow aspects - by subtle adjustments of the output voltage you can manage the energy flow from the Powerwall whatever the car is doing.

    I could easily see Tesla hooking a Powerwall adapter in the Frunk into the CANBus and to the battery through the Supercharger wiring/contactors (or a new group of contactors,) thereby allowing you to hook one or more of the modular boxes in when you need it but not have carry it all the time. The firmware could be set to slow discharge/slow charge the Powerwalls, hopefully minimizing the need for heating/cooling.

    If they ever get around to offering the notional aluminum-air packs we were talking about patents for a couple years ago, those could use the same interface and methodology.

    Thoughts?
    Walter
     
  2. Owner

    Owner Active Member

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    your carrying around 200 pounds for 10kW or 7kW...
     
  3. brianman

    brianman Burrito Founder

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    Assuming you mean 10kWh or 7kWh ;) ...
    That's far more useful than a passenger.
     
  4. Andrew Wolfe

    Andrew Wolfe Roadster 472 - S 440

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    I think that the mounting considerations for a small 200lb object with respect to safety would be a big problem. It also is not designed to be used in an enclosed space without full ventilation. I suspect that the Frunk is not intended to carry 200 pounds either without an impact on handling and/or safety.
     
  5. rolosrevenge

    rolosrevenge Dr. EVS

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    Not if you want to go faster...

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    I've never had any problems with a couple of bodies in the frunk...:rolleyes:
     
  6. brianman

    brianman Burrito Founder

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    Elaborate?
     
  7. Chris TX

    Chris TX Active Member

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    I wonder what this would look like on a roof rack ;)
     
  8. deonb

    deonb Active Member

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    He meant 10kW makes you go faster. 10kWh makes you go further.
     
  9. rolosrevenge

    rolosrevenge Dr. EVS

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    kW is power, more power makes you go faster. kWh is energy, energy makes you go further.

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    You got what I was saying. I figured a hoon like Brianman would get it immediately as well.
     
  10. brianman

    brianman Burrito Founder

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    I suspect that's what you meant but it's incorrect isn't it? More energy means more instantaneous power available, C factor and such.

    Isn't that the primary reason why the S85 is quicker than S60?


    Also, even if what you said is true -- that more energy available doesn't make you go faster, why does an additional 100 lb. passenger make you go faster (or farther) than a 100 lb. powerwall? /confused
     
  11. rolosrevenge

    rolosrevenge Dr. EVS

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    Ah, now you're getting into more specifics as to how the pack is stacked and how the extra energy is added. I was just making the surface observation about more power more speed. You can't over or under think what I was going for. :tongue:
     
  12. wk057

    wk057 Senior Tinkerer

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    I bet it could be done with software from a technical perspective... but no one is going to do it.
     
  13. Owner

    Owner Active Member

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    I did...just was sloppy... sorry
     

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