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Current Power Draw Questions

Discussion in 'Model S: Battery & Charging' started by FDNYLadder33, Jan 4, 2016.

  1. FDNYLadder33

    FDNYLadder33 Member

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    I know this may have been discussed in the past re: a metering device that could track electrical consumption for charging the vehicle. Kill-A-Watt makes a device for 110 Volt applications but no one I've researched has a heavy duty 40A 220V type meter. So, perhaps coming at this backwards may help. Are there any equivalents people have found? A 220V clothes dryer/ air conditioner or electric baseboard heater that uses same/similar consumption. Or is using a 1,500-1,750 watt heat gun (similar to blowdryer) drawing current similar to Tesla charging? If we can find the equivalent in a high power 110V device, perhaps then using a Kill-A-Watt, we can determine exactly rather than approximately.

    Or have people used a separate utility meter for the 220V car charger? I'm in NY/NJ, so our rates vary around the .14-.16 cent/KwH price range. It would be nice to know truly what I am using. At the same time as car purchase, I've invested in LED lightbulbs in many places in the house so I have the conservation savings on one side and greater Tesla power use on the other.
     
  2. brkaus

    brkaus Member

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    Any of the whole house monitors would work. They have a current transformer that is placed on the wire and it runs a meter.

    Personally, I use a monitor from Energy Monitors | Brultech Research Inc

    Many others have been mentioned here, but I can't seam to find them at the moment.
     
  3. FlasherZ

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

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    There are several threads here that cover various solutions. Some have purchased an inexpensive meter base and old mechanical meter to observe their EV charging (and others are required to for their power company). Others have used TED (The Energy Detective) units, and there are a few other brands.

    Tesla charging is going to be the largest appliance, in terms of kWh consumed, for 95%+ of its customers out there.

    I would recommend looking at TED - it's a fairly well-supported system for monitoring. Unlike the Kill-A-Watt, you don't plug the Tesla through the device; instead, you install what are called "CT loops" (current transformer) that measure the current travelling through a wire, similar to how the clamp-on meters work.

    Let me know if you have more questions.
     
  4. EdisonFire

    EdisonFire Member

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    Thanks All

    Tesla charging is going to be the largest appliance, in terms of kWh consumed, for 95%+ of its customers out there.

    I would recommend looking at TED - it's a fairly well-supported system for monitoring. Unlike the Kill-A-Watt, you don't plug the Tesla through the device; instead, you install what are called "CT loops" (current transformer) that measure the current travelling through a wire, similar to how the clamp-on meters work.

    Thanks for your answers. Short of purchasing this type equipment plus installation for a neophyte, do all Model S draw the same current...plus or minus a small percentage? Meaning if you two have this equipment in place, the information you have generated would it be typical for all owners. Then simply multiply that current draw by local utility costs to come up with a safe dollar figure?
     
  5. FlasherZ

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

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    If you base it on kWh, you can generally draw some conclusions. There are some exceptions -- for example, it's more wasteful to charge on a standard receptacle at 120V because the car's charging systems do draw an overhead current. But for the greater majority of Model S owners who are charging at 40A on a NEMA 14-50 receptacle, if you consider number of kWh reported by these tools, you will be able to determine your cost. If all you're doing is trying to determine your share of the bill, this will be sufficient.

    The challenge will be that most people want to have an idea of what it will cost them per mile, which is dependent upon driving style and typical trip. Some (jerry33) have Wh/mile averages of around 250, which is really really good; some crazy drivers have Wh/mile averages of over 400 Wh/mi - this is going to impact any projections you might try to make.
     
  6. jaguar36

    jaguar36 Member

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    The trip meter (under controls on the 17" screen) will show you total energy used in kWh. If you just take that number and multiply it by a charging loss factor (say 1.15) that will give you approximately how much energy you've used. If you want a more accurate charging efficiency number, it depends on what you're using to charge (14-50 or standard outlet), and there are a few threads on the subject like this one.
     

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