Standard Outlet Extension Cord?

[Soundchasr]

Is there an extension cord for a standard outlet that is recommended? When I go to visit my family I'd like to charge a little overnight (the dryer is in the basement so I think that's out..).

Thanks!

 

[liuping]

Any 12/3 heavy duty 15Amp cord should be fine. My wife used this for charging her Volt at work, before they installed Chragepoint chargers: http://www.amazon.com/Yellow-Jacket...1&redirect=true&ref_=oh_aui_search_detailpage

 

[Soundchasr]

Excellent. Thanks.

 

[mrElbe]

Try to keep any extension as short as possible. Line loss will reduce the Amps you can draw without tripping the breaker.

 

[kort677]

FWIW: I use a 65 ft 12g 15 amp cord that get the job done. you aren't going to be pulling more than 3-4 mile per hour regardless of length, it is wise not to keep the cord coiled when in use

 

[TexasEV]

See FlasherZ's home charging FAQ for the answer to this and other common charging questions:
FAQ: Home Tesla charging infrastructure Q&A

 

[SomeJoe7777]

Try to keep any extension as short as possible. Line loss will reduce the Amps you can draw without tripping the breaker.

No, current in amps is constant throughout the circuit (Kirchoff's current law). Amps at the circuit breaker = amps at the plug = amps at the car no matter how long the extension cord is.

What will happen is that the longer the extension cord is, the more voltage drop it will produce, resulting in lower voltage at the car than at the outlet. This reduces total power available for charging, and therefore reduces the charging rate.

e.g. On a dryer outlet, nominal voltage = 240V, circuit rated current = 30A, maximum continuous draw = 24A. In theoretical ideal conditions, power available at the car for charging = 240 * 24 = 5.76 kW.

With long extension cord, voltage at outlet = 236V (4V drop due to the current draw through the building wiring), voltage at car = 226V (10V drop due to 100 foot extension cord), current = 24A. Power available at the car for charging = 226 * 24 = 5.424 kW.


The reason that it works this way for the car chargers is that the chargers are regulating the current they draw. That is an unusual operating mode when compared to other devices.

For example, an electric motor like a vacuum cleaner would behave differently. The motor is under a constant mechanical load, thus must produce an equal amount of mechanical power. A longer extension cord on the vacuum will cause the same voltage drop at the vacuum cleaner motor, reducing it's power output, which will cause it to slow down, which decreases the back-EMF, which then causes current to increase to bring produced mechanical power back to equilibrium with the shaft load. So yes, in this case, the total current draw with the extension cord will be higher than with a short cord.

 

[Zarwin]

DO NOT go by the amp rating on the cord, some are just flat out nonsense. Example:

NO -> Premium 16/3 Orange 15-Amp Contractor Grade Extension Cord Power, 100-Feet - - Amazon.com

That's a 100' 16 gauge cord which is listed as a 15 AMP ... this would never work.

Go by the gauge of the cord. 12 gauge is the thinnest I'd go. I have a 10 gauge 50' cord I use from time to time. It's a heavy sucker, but worth it...