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Extension cord (gauge) for charging M-Y

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To me, depends on use, quality, and cost. Agree the heavier duty isn’t going to charge faster.

But, heavy duty can have better insulation, better plugs/receptacles, and more strands of copper in case some break while flexing. So, potentially a bit more resilient.

if it was something I wanted for travel to keep in the car all the time, I’d go lighter. If it’s regular use in a fixed location, I’d round up. There is also a law of diminishing returns, so I wouldn’t go heavier (but I do have a 50a 25ft cord I left at relatives house to access a 6-50 at the back of their junk filled garage the 2-3 times a year I visit).

So yes, 12ga is enough. 10ga is a bit heavier but won’t change the charging in a measurable way. Personally I’d get 10ga if it’s out a lot and 12ga if it’s a travel cord.
 
It's easy to figure out what the difference is. At 50 feet, let's calculate the difference between 10 and 12 gauge.

10 AWG is 1 mΩ/ft
12 AWG is 1.5 mΩ/ft

Okay, so 12 gauge has 50% more resistance! Sounds like a lot, doesn't it? (Spoiler: no, it's not)

We've got a 50 foot cord; multiply by two because the current flows in both directions. So, 100 feet of wire added to the circuit. The resistance is thus

10 AWG: 100 mΩ
12 AWG: 150 mΩ

The maximum charge rate you can set is 12 A.

E = I * R, so the voltage drop due to the cable is...

10 AWG: 1.2 V
12 AWG: 1.8 V

So the 10 AWG wire gets you an extra 0.6 V to the car. Or in power, it's 0.6 * 12 = 7.2 W

You're getting ~1400 W in either case, so you just have to ask whether spending 30% more and having a 30% heavier cable to haul around is worth it for that extra 7 watts.

I submit that it's not worth it.
Also the cost is almost double. Now I am thinking of 12/3 since the drive will be very much to get groceries and for pleasure. I ordered a 10/3, will get at 12/3 and test it out to see if there is any noticeable difference. If none, I will keep the 12/3.
 
Sorry to revive this thread.
I have a nema 14 50 outdoor at home and need and extension. What kind of gauge wire should I be looking at? I saw some on Amazon but people are telling me it's not safe to run the extension cords, but my charging unit is outdoor to begin with so is there going to be an issue if it rains or puddles and I walk through the puddle? Also, I heard someone mention heat / fire risk when using an extension.

Thanks in advance!
 
Sorry to revive this thread.
I have a nema 14 50 outdoor at home and need and extension. What kind of gauge wire should I be looking at? I saw some on Amazon but people are telling me it's not safe to run the extension cords, but my charging unit is outdoor to begin with so is there going to be an issue if it rains or puddles and I walk through the puddle? Also, I heard someone mention heat / fire risk when using an extension.

Thanks in advance!
Tesla and other EV manufacturers universally state that extension cords should not be used when charging.

If you use an extension cord it should be considered temporary, not a permanent charging setup.

The extension cord should be high quality, as short as possible.

For a 50A circuit use 6 gauge wire minimum (When charging any EV the 80% rule limits charging on a 50A circuit to 40A. This is further reduced when using the Tesla Gen2 Mobile Connector; the maximum charging amperage supported by the Gen2 Mobile Connector with the NEMA 14-50 or 6-50 plug adapter is 32A.)

Inspect the extension cord regularly for signs of damage and overheating.

Keep the interconnection between the extension cord and the equipment off of the ground, dry.

The latest revision of the National Electrical Code requires any new circuit installed for charging an EV be protected with a GFCI either at the receptacle or the circuit breaker. (If your 14-50 circuit is not protected by a GFCI you should turn off the power to the circuit at the service panel before plugging and unplugging the extension cord from the NEMA 14-50 receptacle.)
 
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Tesla and other EV manufacturers universally state that extension cords should not be used when charging.

If you use an extension cord it should be considered temporary, not a permanent charging setup.

The extension cord should be high quality, as short as possible.

For a 50A circuit use 6 gauge wire minimum (When charging any EV the 80% rule limits charging on a 50A circuit to 40A. This is further reduced when using the Tesla Gen2 Mobile Connector; the maximum charging amperage supported by the Gen2 Mobile Connector with the NEMA 14-50 or 6-50 plug adapter is 32A.)

Inspect the extension cord regularly for signs of damage and overheating.

Keep the interconnection between the extension cord and the equipment off of the ground, dry.

The latest revision of the National Electrical Code requires any new circuit installed for charging an EV be protected with a GFCI either at the receptacle or the circuit breaker. (If your 14-50 circuit is not protected by a GFCI you should turn off the power to the circuit at the service panel before plugging and unplugging the extension cord from the NEMA 14-50 receptacle.)
I got my charging unit nema 14 50 installed recently by a licensed contractor and I am sure he installed correctly as I have used in light rain without any issues.

Does Tesla or anyone else offer the cable longer than 20 ft? I need about 30 to 35 ft.
 
I got my charging unit nema 14 50 installed recently by a licensed contractor and I am sure he installed correctly as I have used in light rain without any issues.

Does Tesla or anyone else offer the cable longer than 20 ft? I need about 30 to 35 ft.
If you are currently able to use the 14-50 receptacle with the Tesla Gen2 Mobile Connector why do you need the longer charging cord or an extension cord? If you back in your Tesla vehicle onto the driveway are you able to charge? This may be your best option.

You can find Electric Vehicle Service Equipment (EVSE) with charging cords up to ~25 feet. You may find some off-shore brand EVSE with up to a 30 ft charging cord.

Your electrician could replace the 14-50 receptacle with the Tesla Gen3 Wall Connector (now comes with a 24 foot charging cord.) The Wall Connector is rated for use outdoors and can be exposed to the rain. You could install the Wall Connector on a post, closer to where you park. Underground conduit, wiring would need to be run from the post to where the existing 14-50 receptacle is located (the 14-50 receptacle box would be changed to a junction box.)

At one time you could purchase a Tesla charging cord extender from EVSE Adapters. On the EVSE Adapters web site this product is not currently available.
 
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Extension cord. I need a 6 gauge copper wire extension 10 to 15 ft.
Any of the ones sold on Amazon are probably made in ... Can't say that is bad but you may want to check on EVSE Adapters. Their stuff may be made in ... too but hopefully vetted for use when charging an EV. (The EVSE Adapters extension cord is specifically designed for use when charging an EV, has no neutral wire connection which is not used when charging an EV. Also available in 10 ft length, other lengths.)

NEMA 14-50 Extension Cord for electric vehicle only, 20 ft. – EVSE Adapters