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Charging two Teslas: thoughts on current and future plans

Discussion in 'Model X: Battery & Charging' started by hollyatl, Sep 6, 2016.

  1. hollyatl

    hollyatl Member

    Joined:
    Jan 19, 2016
    Messages:
    51
    Location:
    Atlanta, GA
    We have a detached two car garage/carriage house with 100 amp service. I had an electrician out 2.5 years ago to get a quote for a Nema 14-50 before my husband took delivery of his S only to learn that we don't have enough available amps out there. Options were to either run a new circuit to the carriage house to update the service from 100 to 150 amps or disconnect the existing 60 amp furnace circuit, run a gas line to the carriage house, and replace the existing electric furnace with a gas furnace, thus freeing up the 50 amps needed. Both options were $$$$ so we elected to do neither, and my husband has been charging his S by plugging it into an existing dryer outlet in the garage and using an EV charger in his parking garage at work once a week. He is a very low mileage driver (1 mile commute!) so this has worked well for him.

    I am taking delivery of my X hopefully by the end of the month. We are in the planning stages for a garage/carriage house renovation to begin this winter after our carriage house tenant moves out. Right now our 2 car garage is really only a usable one car garage because the existing furnace and hot water heater on the left side of the garage don't allow an S or an X to pull all the way in. In the short term I plan to park my new X where I always park, which is in the parking pad in front of our home (uncovered, no charger). When hubby is at work and I am home during the day, I can pull into the right side of the garage and charge. He can park and charge there at night, as he currently does. In a pinch (don't tell Elon), I can run over to the supercharger that is about 1.5 miles from my home.

    What should we plan to do once we renovate the garage/carriage house? We will definitely be relocating the furnace and hot water heater up to the carriage house floor so we can park in both sides of the garage. Should we upgrade the electrical service and add a 14-50? Or a HPWC? (The other slightly cheaper option is to run gas service out there, thus freeing up the extra amps needed for a 14-50.). We have looked into solar panels but were told there is too much tree cover. We have a solar panel company coming out next week to confirm. What if one of our kids gets a Model 3 down the road? Any thoughts on long-term charging plans with multiple Teslas? All of this is slightly comical if you could see the very rough alleyway that we drive on to access the carriage house and the many stairs between the carriage house and our main home. Picture main house right at the street and carriage house at bottom of gully way below. I will continue to park in the parking pad unless I need to charge!

    Thanks in advance.
     
  2. ecarfan

    ecarfan Well-Known Member

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    10,366
    Location:
    San Mateo, CA
    That's what I would do: run a new 150A circuit to your garage building and install an HPWC on an 80A circuit (if you have the 72A onboard charger option) and also install a 40A 14-50 plug on a 50A circuit.

    As for one of your kids getting a Model 3 in the future...let them figure it out. ;-). Would they still be living at your house once they have a car like that?

    And by the way, if your husband is only commuting a mile a day he can plug into a 110V/15A volt outlet overnight and he'll get plenty of range for his needs.
     
    • Like x 2
  3. callmesam

    callmesam Member

    Joined:
    Jan 22, 2013
    Messages:
    855
    Location:
    Santa Monica
    Get two HPWCs

    Tesla — Wall Connector with 8.5' Cable
    • Customizable power levels, allowing installations with almost any electrical system
    • Power sharing: Install up to four (4) Wall Connectors on a single circuit breaker
    • Designed for indoor or outdoor installation
    • The 8.5’ length Wall Connector is recommended for easy cable management when installed directly adjacent to a parking spot
    And you don't have to have the maximum amps to each wall connector. And if one is full, the other will get full power. I've yet to see a real life example where a two car family needed to drive 300 miles each/day where you'd need a 4 hour max fill time.

    YMMV
     
    • Like x 3
  4. hollyatl

    hollyatl Member

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    Jan 19, 2016
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    Location:
    Atlanta, GA
    Thanks to both of you! I ended up speaking with my delivery specialist today, and he also recommended two wall connectors (that is what he called them, and he said they would be $500 each for an 8.5 foot cable). I think we will run the extra electricity to our garage and do that, when we get to the renovation stage.

    My son is 14, and I have no idea what he will end up driving down the road, but it will be hard to buy him an ICE when we are driving Teslas and the 3 is available! Right now he wants a "Jurassic Park Jeep." My 12 year old daughter says she is holding off for a self-driving car, preferably a very large one that will fit all her friends...
     
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  5. davewill

    davewill Member

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    437
    Location:
    San Diego, CA, US
    Remember that the new HPWCs can share capacity, so that both wall connectors can have the maximum capacity available when used alone. Just need thicker wire runs inside the garage.
     
  6. nuevodesi

    nuevodesi Member

    Joined:
    Jul 31, 2016
    Messages:
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    Location:
    Dallas-Fort Worth, Texas
    Right ...

    @hollyatl - During the remodel, I suggest you run the appropriate sized power cable [#4/3 for 72amps w/a 90-amp Circuit breaker] along with the communication cable [#18 twisted pair] to both sides of the garage. Having both the cables inside the walls, as opposed to external metal pipes/conduits makes it look much sleeker.

    Also, I recommend getting one of the wall connector with a 8.5' cable while the other with a 24' cable. The longer one would serve two purposes:

    1. Assuming you pull your cars in head first, Install the longer cord Wall connector on the right side of the garage, that way there is enough cable to reach the opposite side of the MS/MX's charging port.
    2. Whenever your son want to plug in the M3, they could use the longer cable as well.
    Good luck.
     
  7. CaliX

    CaliX Member

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    Location:
    Los Angeles
    I also have a detached two car garage/carriage house and two Teslas. I am installing two 100amp chargers to future proof us.
     
  8. GSP

    GSP Member

    Joined:
    Dec 28, 2007
    Messages:
    1,997
    Hollyatl,

    In addition to the good suggestions above for your garage, you may also want to consider adding charging to your parking pad next to the house. Having a 14-50 outlet or an HPWC there would be very helpful until your garage renovation is done. Afterward, it may still come in handy from time to time.

    If your home's electrical panel cannot handle adding a 50 Amp circuit for a 14-50 or HPWC, you can still put in a less powerful outlet, whatever your home panel can handle without upgrading it. The HPWC (High Power Wall Connector) can be configured for any 240 V circuit, from 15 A to 80 A. Even the lower amperage 240 V circuits should still be very useful.

    Good luck with your remodel and new Teslas.

    GSP
     
  9. H: I think you have the solution: you have one car that needs minimal charge, and the other presumably needs significant charge: 110 the former, 240 the latter. Our DS promises our X at the end of the month to join our S, so my plan is usually use a 110 charge for my car (3 mph charge will be 24 miles from midnight to 6) and the 14-50 for Lisa's car which travels lot (40k miles in 24 months). I admit that I have a cringeworthy alternative- 2 14-50s on an antique 100 amp ZInsco panel (before I get flamed, the rails are pristine and the box is clean, clean, clean)...and the cars would have to charge serially. But that will be the rare occasion when we both need a lot of miles...
     
  10. Electric700

    Electric700 Member

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    Location:
    Florida, United States
    Very good advice. I also recommend that if possible, size the wire/circuits to allow two additional Wall Connectors (for a total of four). This way it will be easier to add them if the need comes up in the future.
     
    • Like x 1
  11. dkemme

    dkemme Member

    Joined:
    Apr 3, 2016
    Messages:
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    Location:
    Greeley, CO
    We are a two Tesla family as well, sharing one charger.

    The long ranger drives 40-60 mile per day and charges whenever the range is < 100 mi. The short mileage driver, who experiences severe range anxiety, charges much more frequently. The long ranger grabs the charger in the evening when needed. If the short ranger was using the cord, the long ranger returns it to the the anxious driver's Tesla in the morning.
     
    • Informative x 1

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