TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC

How soon before SPWC for home use?

Discussion in 'Model S: Battery & Charging' started by pilotSteve, May 11, 2015.

  1. pilotSteve

    pilotSteve Active Member

    Joined:
    Jul 14, 2012
    Messages:
    1,102
    Location:
    Vancouver WA
    Thinking that with PowerWall in your garage you could have access to ~400VDC from the PowerWall. Wouldn't it be cool if Tesla offered a "super" power wall charger (hence SPWC) fed from the PowerWall and your solar panels.

    Sure you can use DC->AC->DC with HPWC but it should be 10-15% more efficient as pure DC-DC and quite possibly offer faster charging.

    Home Supercharger anyone?
     
  2. TexasEV

    TexasEV Well-Known Member

    Joined:
    Jun 5, 2013
    Messages:
    6,728
    Location:
    Austin, TX
    How often would anyone need to charge their car that quickly at home? Most people don't come come with a nearly depleted battery and leave for a 200 mile trip an hour later.
     
  3. kuttakamina

    kuttakamina Member

    Joined:
    Aug 23, 2014
    Messages:
    712
    Location:
    DC
    No, but you could come back from a long trip, and may have to make a quick trip to run errands immediately after. I love the idea of a SPWC, throwing in another idea - let us use our Teslas as batteries for our homes.
     
  4. NEWDL

    NEWDL R#350 R#1323 Sig23 8136

    Joined:
    Jan 5, 2009
    Messages:
    475
    Location:
    NE OHIO
    ok, in that same realm of thought, why can't we "jump" each other and transfer X miles of range from one Model S to another?

    DC to DC?
     
  5. stevezzzz

    stevezzzz R;SigS;P85D;SigX;S90D;XP100D;3LR

    Joined:
    Nov 13, 2009
    Messages:
    6,098
    Location:
    Colorado
    The PowerWall is spec'd for a max output current of 2kW continuous, not even close to a 'fast DC charge. Don't know why, but there it is. :frown:
     
    • Informative x 1
  6. Fiver

    Fiver Active Member

    Joined:
    Apr 10, 2015
    Messages:
    1,368
    Location:
    Utah
    #6 Fiver, May 11, 2015
    Last edited: May 11, 2015
    I think this is actually more interesting. While most everyone has no need for "supercharging" speed at home, would a slower straight DC charge connection be more efficient off of Tesla DC home batteries tied to DC solar?
     
  7. Stoneymonster

    Stoneymonster Active Member

    Joined:
    Jan 8, 2013
    Messages:
    1,804
    Location:
    Aptos, Ca
    That's likely the ceiling on the inverter. DC-DC would bypass this. Still, you'd have to have a pretty big stack of these for anything more than a fractional charge.
     
  8. glhs272

    glhs272 Unnamed plug faced villian

    Joined:
    Aug 21, 2013
    Messages:
    850
    Location:
    Burlington, WI
    For this we would basically have to start out with the 100kwh Powerpack, not the power wall. But at $25,000 it's not all that bad, considering what most DC chargers like Chademo go for. That price just gets you the pack, but a big chunk non the less. When you consider what a supercharger site install goes for, perhaps an integrated DC only supercharger/Powerpack on a pallet system might be a good deal for low utilization superchargers. The possibilities are mouth watering.. These in the wild superchargers could be temporary, or only connected with a small standard 100amp to 200amp grid connection, like a typical house.
     
  9. Rockster

    Rockster Active Member

    Joined:
    Oct 22, 2013
    Messages:
    1,854
    Location:
    McKinney, TX
    I've thought about that. It seems technically quite feasible. I wonder, however, if Tesla believes that the mainstream media would spin the announcement of a Tesla-to-Tesla charge cable as an indicator that we need to frequently rescue one another, thus amplifying the uninformed publics' unfounded range anxiety.
     
  10. chriSharek

    chriSharek Member

    Joined:
    Feb 19, 2015
    Messages:
    877
    Location:
    Sarasota, FL
    These are all great ideas. Love the SPWC idea but using the car as a house backup for the Florida Hurricanes would be amazing! :)
     
    • Like x 1
  11. Dbitter1

    Dbitter1 Journeyman Member

    Joined:
    Dec 12, 2014
    Messages:
    201
    Location:
    Chicago, IL
    Uhm.... we are Tesla owners here (or enthusiasts, I suppose). Please don't apply the logic of the common masses; otherwise, we'd all be driving ICEs.

    "The reasonable man adapts himself to the world: the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man." - George Bernard Shaw
     
    • Funny x 1
  12. N4HHE

    N4HHE Member

    Joined:
    Oct 15, 2013
    Messages:
    680
    Location:
    Madison, AL
    What would be the point of "super" charging only 7-10 kWh, even if we could?
     
  13. redi

    redi 2013 P85+

    Joined:
    Aug 31, 2013
    Messages:
    589
    Location:
    DFW, TX
    I'd rather have an option to plug my Tesla in (where my gas generator attaches) so I could power my house during short power outages from my 85kwh "rolling Powerwall" I already have in the garage.
     
  14. NickFie

    NickFie Member

    Joined:
    Sep 28, 2017
    Messages:
    217
    Location:
    Near Philadelphia, PA
    You could have the EV version of a “gas can” with one or two PowerWalls installed in a truck, DC-to-DC connected to a charge cable. That should be able to quickly add some range to a flat-battery EV.

    Tesla Rangers could be promoted to Power-Rangers!

    EV could then be driven to a charge point or power outlet. Less expensive, lower risk than flat-bed transport.

    Mobile PowerWall could be recharged at home base or via generator.
     
    • Funny x 1
  15. Tozz

    Tozz Active Member

    Joined:
    Jan 10, 2018
    Messages:
    1,132
    Location:
    Tynaarlo
    Wouldn't a regular AC charge suffice? I'm not sure about US-spec cars, but EU-cars can charge at 17 kW AC max. Half an hour on 17 kW is 8,5 kW. Enough to drive ~35km or ~22 miles.

    Connecting anything to your car using DC is tricky, as all the safety systems you have with AC charging do not apply to DC chargers. Especially with any "mobile DC charger" this would be a risk.
     
  16. NickFie

    NickFie Member

    Joined:
    Sep 28, 2017
    Messages:
    217
    Location:
    Near Philadelphia, PA
    #16 NickFie, Jul 16, 2018
    Last edited: Jul 16, 2018
    You may have been picturing "jumper cables" used with 12 Volt battery. Would not want to be exposed to 100s of Volts of high-Amperage DC current.

    Fortunately, nearly all EVs are equipped to accept DC charging. I was thinking about a SuperCharger or J1722 type connection. They've provided safe and reliable charging in diverse and challenging conditions around the world.

    Additional DC connection benefits:
    • Faster charge rate than using the car's on-board converters. Both the customer and service provider would likely prefer faster solution.
    • Higher efficiency.
    • Could support vehicles without on-board charger.
    An aside - too close to a half-century ago I worked with a mobile recording outfit. We frequently recorded performances in Greenwich Village nightclubs. When we arrived with our truck, we would run a heavy power cable to the venue's power source to feed our mobile studio. Utility-grade 60 Hz current minimized flutter in our master tapes compared to our relatively noisy onboard generator.

    That area was Edison's original DC power market, and some old buildings still used electric utility DC for systems that had never/not yet been converted to Tesla/Westinghouse AC. We were very careful to identify and verify the AC panel. We knew the risks of raw high-voltage DC to both ourselves and our equipment.

    Still regret joining the mobile recording group after they had recorded for Joe Cocker's Mad Dogs & Englishmen tour, also missed Doors' live album. Though my friends shared a few interesting stories.
     
  17. NickFie

    NickFie Member

    Joined:
    Sep 28, 2017
    Messages:
    217
    Location:
    Near Philadelphia, PA
  18. tnt1971

    tnt1971 Member

    Joined:
    Feb 5, 2016
    Messages:
    202
    Location:
    United States
    Forgetting the speed, the big issue is the inverter loss. Solar produced DC power, and there is an inverter to convert it to AC power. When you charge your car using the standard wall plug or a 14-50, it takes the AC power and converts it back to DC. In each conversion, there is about a 10% loss. The real benefit would be to remove the double 10% loss.
     
  19. .jg.

    .jg. Member

    Joined:
    Feb 27, 2018
    Messages:
    242
    Location:
    Weston Super Mare, England
    Somewhere, a lawyer stirs from their slumber, awoken by that comment :)
     
    • Informative x 1
    • Funny x 1

Share This Page

  • About Us

    Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.
  • Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


    SUPPORT TMC