Questions about safe length of charge cable and outlet options

Questions about safe length of charge cable and outlet options

I wanted to ask for advice on what length of cable (in terms of extension cords) are safe to go up to. The reason I ask is that I have a 240 Volt Nema 14-50(48 amp) plug at the rear of my house (impractical to drive next to for 'reasons') and there are windows right next to where I park where I'm considering running a line to a nearby 110v plug. I don't have a garage but I'm considering a carport sometime around when my Model 3 is delivered. Anyway after spending so much time researching about electricity and charging options in relation to installing a Tesla Home charger or Nema 14-50 I've come to consider regular 110v since most days I drive about 10-15 miles and on days where I go out a lot I drive probably 40-50 miles so I'm thinking I don't need faster charging options. Maybe I can run a cable through a nearby window every night? It won't be far between the charge port and standard wall outlet, I doubt I'll need an extension other than the included cable and adapter, but I also would like to know if I can run an extension cord from my NEMA 14-50 in the back, I'd say the length I'd need is somewhere around 30-40 feet. Can I get an extension cord that long? Would it be safe to use an extension cord that long?
Thanks for any comments. I'm sorry if this is posted elsewhere as I did not see the topic.

alphacompton | 19 giugno 2017

Thanks ReD. The first link may have exactly the cable I'm looking for and the second is very informative on the practice of EV charging cables. Just what I was looking for.

ReD eXiLe ms us | 19 giugno 2017

Cool. Glad to help! The first link has been recommended by many when the subject came up in the Model S forum several times over the years. The other I found in a quick Google search. ;-)

eeb9 | 19 giugno 2017

Handy info!

I'll be stocking up on adapters, as most of my time will be spent in areas away from Superchargers, and my "home" chargers are a set of Ezv chargers at the complex and a single standard 120/15 socket in the garage

eeb9 | 19 giugno 2017

EV chargers, that is...

jefjes | 19 giugno 2017

If the outlet in the back is no longer needed there, how about replacing it with a junction box and install a conduit run from that box around to where you do need it then install the outlet you already have in the location that works for your car charger? The price of conduit, 6awg wiring, and any needed fittings would be cheaper than a cord that long and more permanent, unless you hire an electrician to do it. If you don't know how, forget it and by a cord.

DTsea | 20 giugno 2017

Tesla says 'no extension cords.' What you do is up to you.

DTsea | 20 giugno 2017

Tesla says 'no extension cords.' What you do is up to you.

Quinten | 20 giugno 2017

Hey on the same topic. I am thinking with going with 3rd party charger like Clipper Creek. Does their charger connector also has the button on it to open the charge port door automatically or do one have to manually open from the LCD display console?

Rocky_H | 20 giugno 2017

@Quinten, Well, they call that kind of question a false dichotomy. It's not only those two options. No, regular charging stations like Clipper Creek don't have a charge port opening button on the, since that's a Tesla-specific signal. But, there are a few other ways to open the charging port than having to use the touch screen. The easiest way is that for the past couple of years or so, all of the Tesla models have a charging port flap that can be triggered to open by pressing on it. Also, if you pull the key fob out of your pocket, hold the rear trunk button for about 3 seconds or so, and it will open the charge port.

jordanrichard | 21 giugno 2017

Quinten, you just need an outlet in your garage. There is no need to buy a third party charger. The charger is built into the car.

MN_EV_Driver | 21 giugno 2017

Assuming the 3 will react the same as my Model S, I can give you some anecdotal advice.
Extension cord will sometimes work with regulard 15 amp outlet. If car doesn't like the voltage, it will stop charging and will notify you on the phone app.

Example 1, my wife up at her parents cabin and brought regular extension cord. Car wouldn't charge from it. Brought car closer to house plugged into outlet without extension cord...charged fine. Father in law turned electric grill on. Car stopped charging. It's sensitive to the changes in the circuit, and it if can't draw enough, it'll let you know.
Example 2. Brought car up to friend's cabin for weekend. brought extension cord (different one) and it charged fine (regular outlet) the entire time no matter what we had going on in the house (electric heater, oven, etc) though we were considerate of which circuit we were tapping into.
Example 3. Brought car up to in laws house way up north. they have a dryer. I made a 50 foot cable for a 30 amp (3 prong) connection from parts at Home Depot. Charged fine there.

Rocky_H | 21 giugno 2017

@MN_EV_Driver, Don't try to use regular extension cords. The wire is 16 gauge, which just isn't enough for the sustained level of 12A on 120V outlets. That's why you have all those problems. You need to find one that's at least 12 gauge wire to not have such bad resistance and voltage drop.

sjl | 21 giugno 2017

One other thing. As others have said, running an extension cable to do this job is not a particularly good idea; the reasons have been well explained. But if you DO decide to get an extension cable that is built with thick enough wires to handle the current, and to use it, please: make sure you get one that's as long as you need, and no longer. If you get one that's longer than you need, do NOT coil up the slack - lay it out in long, snaking loops that don't overlap on each other. This is because if you coil up an AC power cable, you're effectively turning it into an inductor - which will result in needless heat production (= energy loss). How much energy loss depends upon just how much of the cable is coiled up - but it's best to not do it, and avoid the problem in the first place.

High Plains Drifter | 22 giugno 2017

I would recommend rewiring a new 14-50 outlet. The additional cost is minimal and will hold up longer.

Iwantmy3 | 22 giugno 2017

Currently I am looking to route a 6 awg wire from my main panel to the outside of my garage (can't park inside). I was considering buying the Tesla wall connector (24')..

Does anyone have experience with these wall connectors in winter conditions?

MN_EV_Driver | 22 giugno 2017

@Rocky_H, @sjl, good advice, thanks. I'll take that into consideration next time i'm not near supercharger or 14-50/14-30.

Rutrow | 22 giugno 2017

sjl is right. And laying a cable in the sun or on hot asphalt can degrade your voltage.

Rocky_H | 22 giugno 2017

@Iwantmy3, The Tesla wall connectors are what are used at all of the destination charging hotels. They are installed outside and are used year round. They are built for that and are outdoor use certified.

SUN 2 DRV | 22 giugno 2017

"This is because if you coil up an AC power cable, you're effectively turning it into an inductor - which will result in needless heat production (= energy loss)."

All depends on whether you wrap it around a magnetic core and how tightly it's wound. :-) At 60 Hz such inductance would have minuscule impact.

But yes it's bad form to coil an extension cord due to the heat build up from restricting the air flow around the conductors. For the same reason that Rutow gives : "cable in the sun or on hot asphalt can degrade your voltage."

accentcreate | 22 giugno 2017

All good advice, just wonder how that translates to Europe and Australia where we have 220/240 volt power supply. Sturdiness of extension cord seems a given. I plan to have the French M3 parked in an orchard as I can't drive close enough to the house or workshop to plug in directly. May have to build a carport with electric supply. We have three-phase power supply in France, which should give even more kick.

SUN 2 DRV | 22 giugno 2017

Also note that the BIG issue with extension cords is the extra connectors which can become worn and loose, more so than just the extra wire length.

A poor connection will introduce very localized and significant heating, which can result in melted insulation, sparks and even smoke and fire.

So even if you buy a heavy gauge extension cord, the wire size won't degrade over time, but the connectors certainly will. So an extension cord that worked fine initially may become very dangerous over time. Hence Tesla's safe recommendation to not use an extension cord.

So I'd be willing to occasionally use a new and well maintained extension cord if I could actively monitor it. But I'd really hesitate to use an extension cord for unmonitored daily charging unless it was outside and guaranteed not to be near any combustible materials. (Same goes for the UMC in my opinion)

hmgolds | 24 giugno 2017

You also have to consider the length of run and the wire gauge to your existing outlet. The longer the run, the heavier the wire you need to avoid excessive voltage drop. My guess is that the Tesla handles voltage drop pretty well, but still best to avoid.

Haggy | 28 giugno 2017

Tesla says no extension cords because they can't certify that each and every one will meet any given spec or that the total length won't be too long when you factor in how far away your outlet is from the circuit breaker.

That being said, many owners use a and have never had a problem with it.

Badbot | 2 luglio 2017

if you have a 14 50 that is not used recycle it to the parking area and save a few bucks