240V 100FT Extension Cord

240V 100FT Extension Cord


I installed a 240V outlet in the back of my house and want to run a 100FT 240V extension cord to recharge my Model S. Has anyone done this, and if so, what mfg extension cord mfg would you recommend?

Thanks for you help.


DTsea | November 13, 2018

Tesla says, do not do that.

TMS | November 13, 2018

Numerous people charge with extension cords just fine, now whether they are 100 feet and 240V is another matter. You might want to consider dialing it back. I personally feel comfortable with 16-20A being pulled with a 10 guage over that distance for regular duty but this assumes there is no other reasonable option.

barrykmd | November 13, 2018

Using an under-rated (<50A rating) extension cord and dialing the current down is a bad idea, Besides violating code, if someone forgets to dial it back before plugging in - poof/sparks/fire/etc. You don't want the extension cord to be your circuit breaker!

There are some RV extension cords on Amazon, but I didn't see any longer than 50 ft. Could you use 2 of them? Sure, but probably not a great idea. You want 6 ga wire and it's going to be heavy.

tes-s | November 13, 2018

My suggestion is put the outlet in the right place for charging. If you make your own extension cord, make it the right length with 6/3 SOOW cable and 6-50 connectors. 25% less weight than a 14-50 with 4 conductors. Also less cost.

DanFoster1 | November 13, 2018

Curious why you don’t run an appropriate cable from your panel to your parking area? I ran nearly 100 feet of 6 gauge for $317.38 (not including the Tesla Wall Connector I installed which you don’t need.) Two, high-quality 50 foot NEMA 14-50 extension cords would cost at least as much, and add points of failure.

You’d need a couple really heavy cords, my dude. Keep the amperage at 80% of rated capacity or below and it’ll be fine—high tension wires are just very long cords too ;~)

If you’re gonna do this long term, keep a good eye on all the points of connection: be sure the contacts are clean, and making solid connections. If they get crappy they’ll overheat, or perhaps the car will notice the voltage drop and dial the current down—Teslas are super-good about that. But…yeah, keep everything clean and firm.

RandallKeith | November 13, 2018

+1 Dan
100 foot extension cord will cost more then a hardwire.

murphyS90D | November 13, 2018

A 50 amp extension cord would have to be at least #6 wire. At 100 feet it borders on needing to be #4 wire. That is going to be a very heavy cable.

kerryglittle | November 21, 2018

Why would anyone cheap out on a proper charging outlet after spending big bucks on a car? Not to mention burning down their house. :-/

bmiksa | January 11, 2019

Fred is probably considering the 100' extension cord for the same reason I am--- Because of the relative location of my circuit box and garage, electricians want over $2,100 to install the charging outlet in my garage!

barrykmd | January 11, 2019

My run was 300 ft and it cost be about $1300. That was 3 1/2 years ago. has the price of copper gone up?

Bill_75D | January 12, 2019

2 years ago I paid a licensed electrician $750 for a 125' run of #6 copper wire, a 50 amp circuit breaker, conduit, and an industrial grade 14-50 outlet.

deemo | January 12, 2019

I use a 30ft RV extension cord rated at 50 amps to charge a Model S (and 3) at 40amps, no issues. Cost was about $100 on ebay. Allows total reach of a little over 50ft with charger cable length.

p.c.mcavoy | January 13, 2019

Cost of the run is not just about the distance of wire. Mine was about a 75’ fun to put a 100 amp sub panel in my garage as the main panel was on the opposite side of the house. Issue is the panel was in the basement, finished ceiling, plug the floor joints running perpendicular to the direction of the run. Much of my cost was due to the roughly 35 feet of finished ceiling that had to be opened up to allow joists to be drilled to get across the basement.

Point is, without knowing all the details of the installation, comparing installation costs is about as useful as comparing insurance costs with no consideration of location, driving history, age, and the other factors that can impact cost.