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Powering home from Tesla

Discussion in 'Model S: Battery & Charging' started by Mike Tuccelli, Dec 24, 2015.

  1. Mike Tuccelli

    Mike Tuccelli Member

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    Would it be possible for a software change to use Tesla battery to feed power into the NEMA plug during a power outage? With 90 KW available, it would be super to be able to run the refrigerator and lights during an extended power outage.
    In 2004 when we had four hurricanes in Florida I was able to plug in a male plug from my generator into a wall receptacle (after turning off circuit breakers) and run the refrigerator and everything on that one circuit.
    Some folks use an inverter to use golf cart batteries for power in similar situations.
     
  2. islandbayy

    islandbayy Active Member

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    No, that is a hardware issue.

    Some companies are making a CHAdeMO To Home connection (Most notably Nissan). And since we have a CHAdeMO adapter available now, it should be "Possible" though that adapter, as it would backfeed the packs DC through the adapter into the Home connection inverter. I don't think any of these systems are in "Production" yet, still beta and testing.
    Might I note though, Tesla SPECIFICALLY states doing this would VOID the warranty. Which is why Tesla is Building the Power Wall.
     
  3. HankLloydRight

    HankLloydRight Fluxing

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    Tesla also doesn't want people to go charge up at a supercharger for free and drive home to power their house, so this kind of reverse power feature likely would never happen.

    What would be nice is a dedicated Model S<-->Model S cable to give another car a "jump" of power if someone is stranded.
     
  4. andrewket

    andrewket 2014 S P85DL, 2016 X P90DL (soon 100)

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    I'd be shocked if the chademo adapter allowed current to flow out. Or perhaps I wouldn't be shocked?
     
  5. Screwbal

    Screwbal Member

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    Just need a 12v to 110 converter, a computer UPS and an extension cord. Really though the UPS will draw more than a 12v to 110 Can put out on the built in cigarette lighter plug but it would almost work :)
     
  6. Ingineer

    Ingineer Electrical Engineer

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    I've got an Inverter in development that can perform this function. The prototype can put out up to 3kW peak and around half that continuously. It provides a pure sine wave, and runs directly of the high-voltage battery. It also has greater than 95% conversion efficiency and is very small.

    If there is enough interest, I will do a production run. It's very useful for powering in-car devices on trips, such as laptops, and could be used in an emergency for running critical appliances. I would think if you only used it in emergency, Tesla wouldn't care. (IANAL!) They probably have language in the warranty to prevent people from deep cycling the pack in a non-car application and claiming warranty when it dies young. Since it's obvious when it's used extensively (makes the watt-hour per mile figure go up), it would be easy for them to tell what abuse is. After all, Nissan even sells a LEAF to Home kit in Japan that does the same. Also, it's essentially no different than sitting in the car and running the HVAC without driving. (In fact, the car really can't tell the difference)

    Running a 12v to 120v inverter is very inefficient, as there would be double conversion (triple, actually), and 12V inverters are not very efficient to begin with. Plus, you can only pull a limited amount of current from the 12v system without overloading it, whereas pulling a few kW from the high-voltage system is nothing.
     
  7. HankLloydRight

    HankLloydRight Fluxing

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    How much power could you get with a big generator on the wheels jacked up like on a dyno? Use two generators for D models.

    (Half joking, half serious)
     
  8. cinergi

    cinergi Active Member

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  9. tom66

    tom66 Member

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    The hardware is there. The car can discharge via the charge connector easily enough, in the same way as it supercharges. And if Tesla wanted to avoid people stealing supercharger energy, they could use an internal counter for kWh which only counts up on AC charging, and you would only be able to discharge that many kWh.
     
  10. andrewket

    andrewket 2014 S P85DL, 2016 X P90DL (soon 100)

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    Until someone charges at a chademo, which also uses DC charging.
     
  11. islandbayy

    islandbayy Active Member

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    Given the fuse to the 12v terminals, and also the charge speed of the 12v battery, 600watt is available. sustained it would keep up with 500 watt charging the 12v from the HV pack. You could use a larger inverter, however, it would be burst use only, a few minutes at a time etc.. (Think coffee maker or toaster).
     
  12. Quantum`

    Quantum` Member

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    Can't do this with the onboard chargers. The IGBTs are one-way only. Two-way chargers are far more expensive.
     
  13. PaulusdB

    PaulusdB Mayor Gnomus Vintage Limb

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    I already support this concept for a while now, calling it 'Buddy Loading'. (Cf. Buddy breathing scuba divers.) I would look silly if a stranded Tesla Motors vehicle can be revived by a mobile charger in the form of a BYD e6 EV.
     
  14. DFibRL8R

    DFibRL8R Member

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    The ability to provide emergency backup power for home from the car is a feature I would really like to see and I believe a major missed peace-of-mind marketing opportunity for Tesla with Model S and X.
    It seems crazy to me to have all that energy locked away in the car's battery while my ice cream melts or my basement floods after a snow storm. It seems equally crazy to spend thousands of dollars on a gas/propane/gasoline powered generator for the rare occasions I loose power. Tesla, of course, will sell me another battery in the form of a 7kWh Powerwall but why buy more battery capacity when I already have enough in the car? I thought Tesla was supply constrained when it comes to battery production. Why force customers to buy more lithium ion batteries to do what could be done with the car? I would much rather pay Tesla for the appropriate hardware/inverter to use the car's stored energy. Better yet, allow it to charge the Model S directly from my solar system too!
    I don't see Model S/X owners mooching electricity from Superchargers to run their homes (seriously there are better ways to save/earn money folks). I also don't see the occasional use for a power outage being enough to damage the battery and void the warranty. I would say the bigger concern is TOU customers routinely selling back the electricity to the grid during peak times but ultimately, if that's how a Tesla customer wants to use their car why not?
     
  15. hiroshiy

    hiroshiy Active Member

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    I'm interested! How do you plan to connect to high voltage battery?
     
  16. HankLloydRight

    HankLloydRight Fluxing

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    You must live in a perfectly honest and greed-free world than the rest of us. Tesla already was a problem with owners using superchargers for all of their local car charging... Given the opportunity to now power their home for "free" is now an even bigger incentive to abuse the system. And you can't define "emergency basis" either ... If this were allowed people would take full advantage of Tesla for their own selfish needs.
     
  17. DFibRL8R

    DFibRL8R Member

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    It has nothing to do with honesty or greed and everything to do with most of us being too busy to bother with such shennanigans. Sure, a few people will always try to game the system to get a "free" lunch (after they pay 100k for a car mind you), and they already do with the local supercharger abuse issue. Even today they could do this with your Tesla-powered-dyno-generator idea (drive to supercharger, charge up, drive home, back-feed the grid with Tesla Dyno-gerator at peak TOU, repeat). But in all seriousness, for the 99%+ of Tesla owners whose hobbies/professions would rule this type of behavior out, emergency power backup from the car would be a nice feature. No need to define emergency either. If the system is grid-tied it can be set up to "know" when the grid has suffered an outage. Regular use for other purposes can be easily identified by Tesla and void the warranty. If someone also wants to save money on peak electricty charges then they can buy a powerwall for this.
     
  18. AntronX

    AntronX Member

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    With 95% eff. seems you are using transformer flyback topology. Is it split phase 120/240V output? Can you post pictures of your prototype?
     
  19. Ingineer

    Ingineer Electrical Engineer

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    It's already connected and my prototype works well. There is still design refinement to be done, as well as optimizing it for cost and manufactureability. Until the design is closer to production, I'm hesitant to release too many details other than to gauge interest. One design target is that it be easy to install and remove, so the connection to the car is done by connectors in a safe and easy manner, and only takes a few minutes to have it operational.

    I'm not worried about Tesla voiding my warranty, because I only tend to use it occasionally. It will have no noticeable impact on battery life, as most of my use scenarios will be very low average power. (Such as powering a laptop while driving, maybe running a portable vacuum to clean the interior once in a while, etc.) IANAL, But under the Magnuson-Moss Act, Tesla must prove that my aftermarket equipment caused the need for repairs before it can deny warranty coverage. So for example, if my Drive unit fails (my biggest concern), they would definitely not be able to say me drawing some power from the HV system caused it. Tesla builds a great car, and the battery packs seem to be very reliable and long-lasting. A few hundred watts of transient additional load is no different than say, running the heater or the A/C. (and in fact, will have way less impact!)

    - - - Updated - - -

    I'm not going to talk about the internal design yet, but right now it's single-phase output only, but it can be easily set for 120v 60hz or 230v 50hz. In theory, 2 could be stacked for split-phase output, but I do not intend on targeting this use scenario. Right now my targets are: high-reliability, low cost, compact, and easy/safe to connect. Because of it's small size, it will not be able to sustain high output for long periods (thermal limit), but it will be able to say run a full-size fridge/freezer and a few other appliances in an emergency. I've successfully used it on a long road trip to heat up meals in a microwave oven which was fun and convenient. I've also ran a bright DLP projector for a Tesla "drive-in" movie. =)

    The new documentary "Racing Extinction" features a Model S equipped with a commercial Christie 4K Digital Cinema projector which I set up to run from the HV system:
    Check Out This Modded Tesla Model S (images + video)
     
  20. hiroshiy

    hiroshiy Active Member

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    Great, if I can install by myself with a bit of electronics skills, I'd like to purchase one of allowed. I will be using that for laptops and BBQs.
     

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