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100 Amp and 50 Amp Service in my garage. Overkill?

Discussion in 'Model S: Battery & Charging' started by Rod85, Apr 26, 2014.

  1. Rod85

    Rod85 Member

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    I'm expecting delivery of my Model S85 in 3 weeks so I had a 100A and 50A service installed in my garage. I had the HPWC installed to the 100A circuit and I can't wait to try it out. I had a 50A service pulled since my electrician was running the line for the 100A and it didn't take much for him to run the additional service.

    I plan to only drive 60 to 100 miles a day. Do you think the 100A HPWC is overkill and will consume much more electricity?


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  2. dsm363

    dsm363 Roadster + Sig Model S

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    #2 dsm363, Apr 26, 2014
    Last edited: Apr 26, 2014
    Congrats!

    For the amount you drive it could be useful if you needed to turn around quickly and get back out on the road. You've already installed it so it will allow you to keep your UMC charging cable that comes with the car in the trunk.

    That said if you are like most people you won't really need to charge at 80A but it's nice to know you have it if you need it. Charging at 40 A is what a lot of people do even if they have the HPWC. It doesn't consume any more electricity than the UMC when charging at the same rate from what I understand.
     
  3. Cosmacelf

    Cosmacelf Active Member

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    You won't use extra electricity when using the HPWC, it'll just use the same amount of electricity doing a charge, but finish sooner. In general, the HPWC is more reliable and robust charging solution than using a UMC, which has a plug and adapters. Save your UMC for the car trunk to use on the road for overnight charging.
     
  4. NigelM

    NigelM Recovering Member

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    Not overkill. I have a HPWC and two NEMA 14-50s in my garage. Of course I have two cars, one of the consequences of enjoying driving a Tesla was that my wife wanted one also.

    What you do need to watch out for is not to run everything at once, don't overload your main panel.
     
  5. Larry

    Larry Member

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    The hpwc is just way easier to use in my opinion
     
  6. nwdiver

    nwdiver Active Member

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    #6 nwdiver, Apr 26, 2014
    Last edited: Apr 26, 2014
    Is that giant switch to the left of HPWC just for the HPWC?
     
  7. Mayhemm

    Mayhemm Model S P85+ "Lola"

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    Rod, you have the exact setup I wanted for my garage (100A HPWC + 50A plug)!

    Due to the existing load on my service, I could only manage a 70A connection for my HPWC though.

    Do you not have any other draws on your electrical or something?

    According to Tesla's calculator, charging with higher-power options like the HPWC is actually more efficient than using low-power options like a wall outlet. A HPWC running at full power only requires 98.9kWh to fully charge an 85kWh Model S while doing the same using a wall outlet apparently takes about 133kWh.
     
  8. Jaff

    Jaff Active Member

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    Not overkill...I have an HPC & an HWPC in my garage...even though we rarely charge each vehicle over 30 amps (on a typical night), plans can change quickly, and I don't like waiting...it is a nice bit of "peace of mind) to know that you can slam the electrons in at 70 & 80 amps respectively if need be.
     
  9. Rod85

    Rod85 Member

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    I'm afraid of enjoying the Tesla too much ... I'll be sure to tell my wife the car is just ok. She too was a skeptic until she read all the rave reviews and talked to several owners. Now she's interested in the Model X.
     
  10. ecarfan

    ecarfan Well-Known Member

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    Not overkill. I had exactly the same setup installed before I took delivery of my S85 last year.
     
  11. Rod85

    Rod85 Member

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    Mayhemm, Thanks for the post. My house was built with a 400A service so my electrician said no problem to add these ... I guess we'll see how this works when I get the car.

     
  12. Doug_G

    Doug_G Lead Moderator

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    Not overkill - you never know when you might get a second EV.

    I have a NEMA 14-50 for daily charging of my Model S, and a Roadster HPC for the Roadster (of course). I usually charge both cars at 40A, even though the HPC is capable of 70A. (Unlike the Model S, the Roadster is a little more efficient at moderate power levels.)

    However, I converted the HPC to J1772 so if I ever need to charge the Model S more quickly I can use 70A. I have to park it in the driveway for the cord to reach, but no biggie. I think I've done that twice. 99% of the time 40A is plenty.
     
  13. Canuck

    Canuck Active Member

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    So true. I just bought a 2012 Leaf SL for my daughter yesterday. I wish I had installed two just a few months ago -- now I have to get the electrician back.
     
  14. Rockster

    Rockster Active Member

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    I have the same setup. I put in the 14-50 first, then the 100 amp HPWC later. I rarely charge at 80 amps. Only when we need a fast turnaround. It's nice keeping the UMC in the trunk and only charging with the HPWC.
     
  15. Canuck

    Canuck Active Member

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    Why do you charge under the capacity of the HPWC? Are you concerned about battery degradation at higher amps?
     
  16. invisik

    invisik Member

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    (...or if a friend is over with their EV)

    Exactly. I had our service upgraded to 200amp and had the HPWC and a 14-50 installed in the garage at the same time. We're set for whatever happens! :)

    PS: I haven't had a chance to try either of mine yet too

    -m


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  17. David99

    David99 Active Member

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    It does't hurt to have both options. if the HPWC ever has an issue you have the other option as a fallback. the difference in efficiency of charging at 40 vs 80 Amp is insignificant. In general, charging at full 80 Ampere has little advantage. even a completely empty 85 battery is fully charged (range charge) over night using 40 Ampere. That's why I didn't bother getting the dual charger. My home charger will be just a second UMC that stays in the garage plugged into a 15-50, which is half the price of a HPWC.
     
  18. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    I have HPWC + NEMA 14-50 at the moment (and a 6-50 in the welding shop across the concrete). I just had the power company do a calculation on my transformer for a second HPWC (Model X is coming soon!), but that's going to require a new power feeder to the garage.

    Definitely not overkill, as many others have said.
     
  19. techmaven

    techmaven Active Member

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    When I ordered the Schedule EV service from Virginia Dominion Power which provides a separate metered connection for EVSE's, I asked them to increase the standard 100A service to 200A. They did some calculations and was fine with it. So now I have 600A to the house and 200A to the garage. I did this so that I could have 2 x HWPC at full power or downgrade the 2 x HWPC and add a 30A J1772 also for 3 x EVs.
     
  20. Lloyd

    Lloyd Active Member

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    Yes, Hubbell makes one that is a little smaller for someone who is space concerned, but more expensive. The circuit breaker can also serve as a disconnect if it is accessable.

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