Every Tesla, like any electric vehicle, needs consistent recharging. There are many reasons why it is more convenient to use an extension cord for your electric car. This means that to use an extension cord safely, you will need to get good cables. This allows you to reliably connect your vehicle to the Tesla charger.

A NEMA 5-15, 14-50 or J1772 extension cord, they can both provide the extra length you need.

BEST CHOICE FOR REGULAR OUTLETS
Coleman 10 AWG • Heavy Duty Extension cord • 25/50/100 ft
Fast and reliable solution for connecting the Mobile Connector or any EV charger through a 5-15 outlet
Safe cable gauge of 10 AWG for a large and stable load. Fits Level-1 charger and reliably handles the load. Certified product.
Read Verified Customer Reviews

The portable charger that comes with your electric car (purchased in North America) has a NEMA 5-15 connector, which is the most common household outlet. This connection is limited to 15 amps, and not a high charging rate, which will add about 3 miles of range to your electric car per hour of charging.

The recommendations of a portable charger, whether the Tesla Mobile Connector Gen 3 or any other, draw the user’s attention to the dangers of using an extension cord. This is absolutely true, as often the cables chosen do not match the power of the charger and its long, uninterrupted runtime.

If you decide to use an extension cord, we strongly recommend that you take no chances and choose a cable with a 10 AWG (gauge) and marked SJTW. This, among others, is the safest cable characteristic that can withstand the loads for a 5-15 socket. These are the models you’ll see in our review.


BEST CHOICE FOR TESLA & NON-TESLA
Camco 30-Foot • NEMA 14-50 • 50 amp cable
Reliable and fast solution for connecting any EV charger
Optimal cable gauge for Tesla Mobile Connector and other EVSE via NEMA. Reliably withstands the load needed to charge an electric car. Does not heat up and has sturdy connections. Certified product. Flexible cable makes it easy to wrap. Comes with a nice carrying strap.
Read Verified Customer Reviews

If you have a NEMA 14-50 outlet (the kind of outlet your dryer plugs into, for example), it can add about 23 miles per hour to your electric car, not 3 miles per hour anymore. A portable charger or Tesla Mobile Connector with a purchased 14-50 adapter can be used for this purpose.


BEST CHOICE FOR NON-TESLA
Lectron 40ft/12m J1772 Extension Cable Compatible with All J1772 EV Chargers
Flexible Charging for Your Electric Vehicle
With a focus on safety, efficiency, and durability, Lectron leads the way among extension cords, which is reliable, easy to use, and compatible with many electric vehicles.
Read Verified Customer Reviews

From our experience, the safest and most moisture-proof extension cable between the charger and the electric car’s inlet is considered the safest. There are no extensions like this with Tesla connectors, unlike the J1772 connector. That said, some Tesla users also use this kind of an extension cord because it is available with adapters of different directions.

Making an extension cable purchase is, for most users, just a functional thing and most don’t want to spend too much time pondering and analyzing this decision. If you are new to electric vehicles, then some terms may be new to you. Just like diesel and gas, electric vehicles have many different methods of getting the same job done.

It has to be the right caliber and length to charge your car without any problems. The Tesla charger extension cord is a 14-gauge wire. It can be used both at home and on the road.

Best 10-gauge extension cords for regular outlets

We have chosen a handful of models from the AWG 10 range of extension cord models. The Coleman extension cord is made from vinyl braid. It is moderately flexible but durable and can be used outdoors. The Coleman 50-foot extension cord is very popular among EV Adept customers. When used with TWC and a 12amp load, the cable did not heat up.

Flexzilla c potentized multilayer braid construction is a great choice for flexible cables. It can hold up to daily use. Our team was quite surprised to see the 100-foot glow-in-the dark cable. The glow-in-the dark feature will make it easier to use and prevent you from stumbling around in the garage at night.

Some other models, such as the Yellow Jacket and Iron Forge, have held up to the competition and can be used for charging an electric car without an outlet. There are several length options available that will allow you to reach up to 200 feet from an outlet.

Charging your Tesla can be a challenge when the outlet is out of reach of the charging adapter.

This can happen when traveling on a less-traveled route away from urban areas where we can use Superchargers, or even at home if the outlet is far from the garage or regular parking spot.

When taking a Tesla to a campsite, you can use many residential RV outlets to charge the car because they provide the amount of power needed. But again, you need to be close enough to it to be able to plug in a mobile charger, and that’s not always possible.

When choosing the best NEMA 14-50 extension cord, what matters to us is

  • Technical specs
  • Length
  • Handle comfort
  • LED power indicator
  • Brand
  • Certification

Charging cable extenders can give you an extended cable length of up to 50 feet, so you can reach outlets up to 70 feet away from your Tesla. The J1772 adapter comes with the Tesla, so you can use this type of extension cord easily.

Common plug types

Plug types

The common term that all of the above connectors fall under is “EVSE”, or electric vehicle supply equipment.

Today we will be focusing on the NEMA 14-50 and J1772 connector types because these are the only plug types that allow using extension cables.

NEMA OR J1772. Which extension cord is the best?

When comparing the two options, keep in mind the following four criteria:

  • Safety – is the product subjected to the elements and used in areas where people are often present?
  • Technical requirements – does it fit your needs or other appliances?
  • Portability – how often do you need to coil and uncoil the cord? How often do you need to store it?
  • Aesthetics – does the design matter? All of the above products vary in color and design
NEMA 14-50 vs. J1772

Comparison of NEMA 14-50 vs J1772 standard

NEMA 14-50 extension cableJ1772 extension cable
ApplicationUniversalSpecifically designed for EV charging
PriceLowerHigher
Max Current for the standard50A80A
Nr. of pins4 (hot, hot, ground, neutral)5 (hot, neutral, ground, proximity sensor and control pilot)
Overheating protectionNoYes
WeightLighterHeavier
NotesShould be preferred for light-duty applications or if charging occurs infrequently.A more proper solution is that the cables are sturdier and have more safety features, like overcurrent, overheat, and overvoltage protection.

Let’s put it this way—a steak can be cut with any knife, but using a dedicated steak knife feels better and smoother. NEMA is the generic knife in this example. It is a universal option with a lower price, lighter weight, and this makes it also more portable. J1772 is specifically designed for EV charging. This makes it more convenient to plug in and unplug, a heavier but much safer option.

Charging with NEMA cable is considered safe, but why take chances when a more proper and safer option is out there?

NEMA standard is great but still inferior to J1772

Electrical code requires NEMA 14-50 to be installed with a ground fault circuit interceptor (GFCI). All modern cars are already equipped with a GFCI breaker, and two of those in consection tend to trip each other. This makes NEMA a bit of a less reliable option. It can be frustrating when you’ve charged your car before a long trip just to find out that the charging session has stopped in the middle. 

The NEMA 14-50 outlet quality depends on your electrician. Cheaper outlets have been known to melt after a few months of continuous EV charging. It is understandable, since NEMA connectors are often used in short windows. Your oven or RV may pull max power for a while, but EV charging pulls maximum amps continuously. 

J1772 can deliver more power. Even if your EV is not able to accept all that extra power, then most likely some of your visitors may appreciate it, and your next EV is likely to come with a more powerful onboard charger. 

We recommend a dedicated wallbox style charger. Even Tesla does not offer a charger with a NEMA connector as standard anymore. That is their way of politely saying that people should opt for a wall-mounted charger.

NEMA is an excellent fit for some cases

If you own a condominium, then installing a proper Level 2 charger could be tricky since you probably need the green light from the HOA. With NEMA 14-50 outlet, it may be much easier.

Good idea
You can find NEMA extension cables even 50 feet long. If your parking spot is farther away from the power source, then this could be a deal-breaker for choosing a J1772 extension cable.

J1772 is a more prevalent extension cord for an EV enthusiast

If you are an EV enthusiast, no other solution should be considered. You know you will be charging your car frequently and you want a proper solution.

Most EVs come with a dedicated charging adaptor that may or may not support the NEMA connector. Choosing J1772 means that you also have a wallbox type charger. This means that you can keep the charging adapter in your trunk for emergencies.

If you know that you are not going back to ICE vehicles, then why not choose a better solution today?

Safety Tip
Keep it in sight and protect it
If you use the extension cord in a garage or in places where the cable may be subjected to mechanical impact, use special protection with an extension cord cover/protective ramp. Do not run extension cords under rugs or furniture.

J1772 extension cables

If you have already decided to go with J1772 cable, then the only criteria left to choose from are length, materials, portability, resistance to elements, and design.

J1772
ImageProduct 
Best Choice
Lectron 40ft/12m J1772 Extension Cable review
Lectron 40ft/12m J1772 Extension Cable
  • Reasonable price
  • Silver plating inlets provide lower resistance – lower voltage drop
  • Well built with rugged materials

Check Price
READ OUR REVIEW
Also Great
MUSTART 40 Amp 20 Ft J1772 Extension Cord review
MUSTART 40 Amp 20 Ft J1772 Extension Cord
  • Slightly higher water resistance level
  • Included portable bag
  • Heavy-duty cable materials provide confidence in the durability

Out of stock
READ OUR REVIEW
Also Great
LEFANEV 40A 20 Feet EV Charger Extension Cord review
LEFANEV 40A 20 Feet EV Charger Extension Cord
  • Low weight
  • Clean look
  • Covers all J1772 standards

Check Price
READ OUR REVIEW

Comparison of the J1772 extension cables

LECTRONMUSTARTLEFANEV
Length options40ft25ft20ft
ConductivityBestSatisfactorySatisfactory
MaterialsCopper, high strength ABS plastic, silver plating on inletsCopper, PVCCopper, PVC
Warranty3 months2 yearsContact seller
Weight17.46 pounds‎9.9 pounds5.5 pounds
Max power rating40 Amps40 Amps40 Amps
IP ratingIP66IP67IP66
Water resistanceGoodBestGood

All of the products above offer great safety, so choosing a product with a compelling design is also not a bad idea. Yes, the materials, durability, and weight do also vary, but since most users will use these electric car extension cords as a stationary solution, it does not matter much.

Product #1. BEST CHOICE. Lectron 40ft/12m J1772 Extension Cable Compatible with All J1772 EV Chargers

The Lectron J1772 extension cable should be your choice if you don’t feel like researching too many options for your extension cable needs. It is the most reasonably priced cable with a few features that even more expensive models don’t offer. 

The plug, cable, and connections are more on the heavy-duty side. This might be the most important feature since the cable will be laying on the ground for most cases.

The silver plating in inlet provides great conductivity. With longer cables, you can expect a slight voltage drop. Similar to how water pressure in long pipes decreases due to friction. It’s the same thing with electrical cables. Silver plating lowers the resistance and lowers the voltage drop. With long cables, every bit of conductivity helps.

With an IP66 rating against water and dirt, it is dust-tight and resistant to water jets.

Pros

Competitive price

Silver plating inlets provide lower resistance – lower voltage drop

Well-built with rugged materials

Cons

Short warranty period

Product #2. MUSTART 40 Amp 20 Ft J1772 Extension Cord for EV Charger Electric Vehicle Charging Stations (Updated Version)

This extension cord should be preferred if used in locations where it is exposed to the elements or needs to be carried around. Out of the top three cables we reviewed, it was the only one with a portable bag. 

It has a slightly higher water resistance level. By just looking at the IP standard, it states that the IP67 level products are dust-tight and can be submerged into 1m of water for up to 30 minutes. This should not be taken too seriously, since the standard covers clean, freshwater with no movement. In real life, water is rarely pure and moving water can still leak in.

Out of the three, it scores highest in the design category, but the cable itself does not feel that durable. At the same time, when not subjected to heavy wear, this extension cord should work wonderfully.

Pros

Slightly higher water resistance level

Portable bag included

Heavy-duty cable materials provide confidence in the durability

Cons

Materials feel less durable

Product #3: LEFANEV 40A 20 Feet EV Charger Extension Cord for J1772 Electric Vehicle Charging Stations

With a length of 20ft, it is also shorter and, therefore, a lighter cable. Colored connectors or cables serve an important function since the extension cable is usually used in places where you would not expect to find a charging cable lying around. At the same time, you’ll appreciate the clean look.

It is the lightest of the three. If a portable bag were to be included, it would be the most convenient cable extension out there. If you do choose to carry it around a lot, then a “figure 8 parachute fold” method does the job without any straps and bags. 

This EV cable extender should be preferred when low weight and clean look is preferred. Other than that, the features are very similar to every other product in the market.

This cable covers all J1772 standards. At the same time, no extra steps have been made by the manufacturer to make it more user-friendly. The cable itself feels like it would not like an occasional car driving over it which can occur with extension cables.

Pros

Lightweight

Clean look

Cons

It may be less durable due to the simple materials used

Safety Tip
Use this as a temporary solution
Use extension cords only on a temporary basis; do not use them to power permanent appliances like EV charging stations, washer/dryers, or other heavy-duty machines that can be permanently wired into the structure of your home. Extension cords are meant only for temporary connections between an outdoor extension cord and smaller indoor appliances (ex. EV portable chargers), not for powering the entire garage in your house.

NEMA is the best for a quick start

When you are debating between NEMA and J1772, then it helps to consider that you can’t go wrong with either, so choosing a more budget-friendly option will still work great. Even if you end up not charging your vehicle with it often, chances are a NEMA extension cord will come in handy at home. It can be used in a variety of applications from ovens and generators to RVs. 

It is priced lower and gets your EV battery charged. NEMA wall connector is simpler to install and some buildings already have it installed. If you have the connector already installed, it will be a logical solution for charging your car if you wish to avoid extra hassle. 

You may appreciate the lightweight style, which makes it relatively easy to carry around or store.

Nema 14-50 extension cables
ImageProduct 
Best Choice
Camco 55542 25-Feet 50 AMP review
Camco 55542 30-Feet 50 AMP
  • Competitive price
  • High conductivity
  • Flexible cable makes coiling easy

Check Price
READ OUR REVIEW
Also Great
Ceptics GN-CD-16A-50 Ft 50-Amp Auto EV Extension Cord review
Ceptics GN-CD-16A-50 Ft 50-Amp Auto EV Extension Cord
  • Lifetime limited warranty
  • Multiple length options: 10ft, 30ft, 50ft
  • UL listed – tested by a third party for quality

Check Price
READ OUR REVIEW
Also Great
Miady 30ft 50Amp Heavy Duty RV/EV Extension Cord review
Miady 30ft 50Amp Heavy Duty RV/EV Extension Cord
  • Plug and socket feel well built
  • ETL listed
  • Comes with a handy carry strap

Check Price
READ OUR REVIEW

Comparison of the Nema 14-50 extension cables

CamcoCepticsMiady
Length options25ft10ft, 25ft, 50ft30ft
MaterialsHeavy-duty heat resistant PVC, copperPVC, copperPVC, Copper
Hot wire size#6 gauge#8 gauge#6 gauge
Organizer or strapYesNoYes
WarrantyContact sellerLimited lifetime warrantyContact seller
WeightN/A35.6 pounds21 pounds
Max power rating50 Amps50 Amps50 Amps

Product #1. BEST CHOICE. Camco 55542 25-Feet 50 AMP Standard Male / 50 AMP Locking Electrical Adapter

A reasonably priced, simplest, and most practical NEMA 14-50 extension cable. Although it was not the most expensive cable we reviewed, it felt well-built in the hand, as though careful craftsmanship has been put into making this product. 

One possible reason why it looks and feels to be better quality may be because out of the three companies reviewed, the Camco company has the longest experience in manufacturing cables like this, so they have had time to work out all sorts of kinks. 

Most cables like these will be occasionally stored in the trunk of an electric vehicle or the garage, so the flexibility comes in handy when unwinding it or coiling it. The handle straps make it easy to carry around and store.

Pros

Materials used feel high quality

Flexible cable makes coiling easy

Competitively priced

High conductivity

Comes with a good looking carrying strap

Cons

None

Product #2. Ceptics GN-CD-16A-50 Ft 50-Amp Auto EV Extension Cord (Recommended for Tesla Users Model 3/S/X/Y) | Nema L14-50-UL Listed-50A, 125/250V

Simple, yet sturdy. This product should be preferred for stationary application since the weather-resistant coating feels stiffer and there are no straps for carrying it around. 

The cable is heavy duty and most would probably feel quite safe occasionally driving over the cable. The manufacturer produces mostly travel adapters and has started producing cables like this more recently. At the same time, they do offer a limited lifetime warranty but keep in mind that shipping the item back to the manufacturer in China could potentially cost you more than buying a new cable.

UL-listed — this is important. With the popularity of electric vehicles increasing, some startups and companies push their products to market in hopes of profiting from the trend. This could lead to rushed designs and poorly tested products. “UL-listed” means that the product has met the UL safety standards and that this has been verified by a third party.

Pros

Lifetime limited warranty

Many length options: 10ft, 25ft, 50ft

UL-listed

Cons

The cord is stiffer and makes coiling less comfortable

No convenient grip handle for unplugging

High price

Product #3. Miady 30ft 50Amp Heavy Duty RV/EV Extension Cord, Easy Unplug Design with Cord Organizer, 6/3+8/1 Gauge, ETL Listed

This extension cable should be chosen if the product is often stored, coiled, or carried around because the lightweight and carry strap makes it very convenient for frequent use. It is designed for RVs and less for electric vehicles. Usually, cables for electric vehicles are used more often than the ones for RVs. This shows in the design.

Compliments to the plug and socket engineers! The materials feel good and the handle is comfortable. The company sells the plug and socket separately quite successfully, so it seems like they have this part of the product well-thought-through.

Lightweight combined with a carry strap makes this extension cable one of the most comfortable cables to carry, coil, and store. 

ETL Listed – provides more confidence in the quality and reliability of the product although the materials do not seem any better. The plastics used even feel a bit more on the cheap side.

Pros

Socket and plug feel well-built

ETL listed – tested by a third party for quality

Comes with a handy carry strap

Lightweight

Cons

Materials appear to be cheaper

It may be designed for less frequent use – designed for RVs

Safety Tip
Water-resistant
Be particularly careful around water, which can conduct electricity more easily than dry areas. If you live in a high-humidity climate near lakes or beaches, attach extension cords to an outdoor-rated cord for added protection against corrosion. Be sure your home is wired with sufficient grounded electrical receptacles for EV chargers or other new items you bring into your house or apartment.

Product #1. 10 AWG Coleman / Southwire Extension Cable Review

This heavy-duty 10-gauge extension cord (NEMA 5-15) is perfect for powering large tools and appliances such as an EV charger or multiple drills, a large heater, or other high-power devices. The cord is 100 ft long and features a bright yellow vinyl jacket that resists oil, grease, moisture, and abrasion. The lighted end shows that the cord is ready to use, and the strain relief clear molded plugs help protect against damage. The Underwriters Laboratories Inc. (UL) certification means that the product has been evaluated for safety.

You may find that the power cord for your EV charger is no longer made by Coleman. It’s now manufactured and branded by Southwire, which is the parent company of Coleman. The new cable has some changes from what you’re probably used to seeing. They have improved the ground wire’s gauges, among other features. This means the current will flow more freely through all the copper wires within the insulation since they no longer share space. Product page → Coleman outdoor extension cord for EV charger.

Product #2. 10-gauge Flexzilla Pro • Most Flexible Extension Cord Review

This NEMA 5-15 cord was designed to withstand the most demanding applications and features industrial-grade material. The protective thermoplastic SJTW jacket is abrasion- and corrosion-resistant and built for outdoor use. Lengths range from 25 to 100 feet.The Flexzilla Pro is a flexible, durable, and weather-resistant extension cord. This power cable features a glow-in-the-dark stripe for easy identification in low light conditions. This extension cord resists kinks and coils easily for convenient storage. It has an all-weather flexibility rating of -58°F to 140°F, so you can use it for connection with an EV charger safely in any climate or environment. Product page → Flexzilla heavy duty extension cord for EV charger

Product #3. 10 AWG Iron Forge • Multi Outlet Extension Cord Review

Iron Forge is proud to offer our high-quality, multi-use extension cords (NEMA 5-15). This heavy-duty 15-amp 125-volt 1875-watt cord can be used for a variety of applications including: electric vehicle chargers, lighting, power tools, appliances, and more. It features a grounded 3-prong plug on one end and a 5-15P/R outlet on the other end. The durable vinyl jacket resists moisture and abrasion while the built-in strain relief protects against damage from repetitive flexing. 

With 3 outlets in 1, this cord is perfect for powering any household appliance—from your air conditioner to your lawn mower. The water-resistant, flexible vinyl covering protects the cords against moisture, abrasion, and sunlight, making it ideal for use in any environment.

Iron Forge’s Extension Cord has reinforced plates that protect the prongs from bending or breaking and a slip-resistant design. The cord is also temperature-resistant, with a lifetime replacement warranty. Product page → Iron Forge extension cable for Tesla charger

Product #4. Yellow Jacket 10/3 • High-load Extension Cable Review

The Yellow Jacket 10/3 100-ft heavy-duty extension cord (NEMA 5-15/5-20) is recommended for use with heavy-duty equipment and tools such as a Level-1 electric vehicle charger. This 3-prong extension cord is durable thanks to its 10-gauge wire. The Yellow Jacket features a weather-resistant, high-gloss finish and resists oil, grease, moisture, and abrasion, making this extension cord tangle-free. Total power outlets:1; Cord Length (Feet):100; Color:Black; NEMA direction: 5-15P to 5-15R.

This contractor-approved extension cord is a must-have for any job site. The lighted end shows that the cord is live and ready to use, while the heavy-duty strain relief plugs help to keep the cord in good condition for longer. This UL- and CUL-listed cord is powerful enough to handle up to 20 amps of power, making it perfect for big jobs. Product page → Yellow Jacket extension cord for Tesla Mobile Connector.

Product #5. LifeSupplyUSA •  Long length Extension Cable Review 

The thermoplastic SJTW jacket is abrasion- and corrosion-resistant and designed for use in the elements. There is no range of length, just one maximum length of 200 feet. The Extension Cord 10/3 SJTW with lighted end is perfect for both indoor and outdoor EVSEs. The heavy-duty protection makes it resistant to oil, grease, moisture and abrasion, while the rugged vinyl jacket ensures durability. It’s also highly flexible, making it perfect for extreme temperatures.

Compared to other shorter cords, it has a lower number of allowable amps, but this is due to the maximum possible length. When using it with the charger, you should set the electric car to consume 10 amps to avoid overheating. 

This 200-ft. extension cord is perfect for use with not just EV chargers but also power tools, appliances, and more. The lighted end indicates when the power is on, and the bright PVC jacket color makes it easily visible. It’s 10 amps, 125 volts, and 1250 watts, making it perfect for heavy-duty use. Product page → LifeSupplyUSA longest 10-awg extension cord

Tesla-to-Tesla extension cord

There are times when you need to connect to a neighboring charging station in a public parking lot. Also for hardwired Wall Connector owners, this product is the only way to extend the power cable. If you own an HPWC gen 3 where the cable is too short, you know the pain of having to charge a guest’s electric car.

This cable is still not easy to find in stores, because of the strong requirements to the high voltage load. Prototypes are sold in small batches through authorized charger installers.

Product 2022. Tesla Supercharger Extension Cord 14ft Review

With silver-plated inlets, it provides good conductivity to prevent overheating, and has a minimum voltage drop in cold weather. Features all pins that are machine crimped for better connection. Plus, the ergonomic handles are machined from Ultraform for a comfortable grip.

This cord is AC/DC compatible. No heating above the proprietary cable was noticed during the Supercharger test. When charging is complete, the internal unlock mechanism works, which allows you to remove the cable from the car port without the owner. This is, in our opinion, a disadvantage because the cable can be stolen.

The second disadvantage is the cable length of 14ft so compared to the J1772 cable, the first is 6ft shorter. At the same time, the short length gives the possibility to use the extension cable on Supercharger charging stations. The product can easily extend the reach of your charger, so you can charge your Tesla with ease. Product page → Tesla Supercharger Extension Cable 14ft

What is the difference between UL and ETL listing?

No difference except the body that issues the listing.

Safety Tip
Use proper AWG
The cable wire gauge on an extension cord determines the amount of electricity that can flow through it safely. Look for a cord with a wire gauge at least as high as the amperage of all appliances you plan to plug into it and no higher than needed for any appliance. This helps prevent overloading. Note that the higher the AWG number, the less power the cable can carry. For Level-1 devices, we've selected the best 10-AWG extension cables here.

What do “6/3 + 8/1”-gauge wires mean?

The gauge number indicates the thickness of the cord in terms of American Wire Gauge (AWG). Common extension cords are available in 16 gauge to 10 gauge, with the higher number indicating a thinner wire and lower gauge number indicating a thicker cable.

  • “6/3” marking means that there are 3 conductors with gauge #6. These are for the neutral wire and two hot wires.
  • “8/1” marking means that there is one wire with gauge #8. This is for the ground and should not carry any current.

With length the resistance of the cord increases. Choosing a thicker cable enables reducing the voltage drop and the risk of overheating. Even if the cables are good, the connector could potentially overheat if the contact between the metal surfaces is not ideal. Using high-grade contractor materials like silver-plated copper helps to reduce that risk a great deal.

Safety Tip
Use only grounded cords
Do not remove the grounding prong or use an adapter plug to fit three-prong appliances into two-prong outlets.

Never remove the ground pin (the third prong) on grounded power cords, as this can create a hazardous situation where there is no recourse if someone becomes electrocuted, and it may void your EVSE guarantee.

Be sure your home is wired with sufficient grounded electrical receptacles for new items you bring into your house or apartment; always consult with an electrician if you are unsure about how many circuits are running throughout your home.

Insulation materials for extension cables

The outer jacket of an extension cable protects against high temperatures, physical stress, and chemical substances, among other hazards.

The extension cables we’ve reviewed are made of abrasion-resistant and low-adhesion PVC, PUR, or TPE that have been coated to meet the requirements of the application.

PVC (Vinyl) cable is particularly abrasion-resistant and ideal for use in lighting technology, packaging machines, and assembly lines. It is resistant to permanent moisture and salt water but not halogen-free. PVC has the best price-performance ratio in the low-voltage range. It’s not ideal for EV chargers. 

PUR (Polyurethane) is a halogen-free and self-extinguishing thermoplastic elastomer. It has excellent chemical resistance, good electrical properties, low temperature flexibility and high tensile strength. Its outstanding physical properties make it the ideal material for use in machine tools, plant construction, or cement plants. It is also used to protect cables in automotive applications thanks to its abrasion and notch resistance. 

With a temperature range up to 400°F (205°C), PUR is rubber-like and has low temperature flexibility, making it an ideal choice for applications where other materials would not stand up to the demands.

A TPE cable is a thermoplastic elastomer material that is commonly used for flexible cables. It can reliably withstand mechanical loads and has resistance to external influences such as chemicals and extreme temperatures. TPE is generally suitable for a temperature range of -31˚ to 212˚F. Offered as halogen-free or flame-retardant, UL 94-HB-compliant TPE cables handle harsh environmental conditions and continuous movement very well. Often found in crane applications or material handling, TPE cables are a great choice for your charging or industrial needs.

Is it safe to use these cables in the rain and snow?

Some people don’t feel safe even when washing an electric car or letting it sit in the snow or rain with a charging cable attached. Engineers in automotive companies have thought about these dangers and built-in safety features to tackle them. Every EV charger extension cord is protected with short circuit protection and residual current protection.

A short circuit occurs when a current travels along an unintended path, often where essentially no (or a very low) electrical impedance is encountered. In simple terms, the device detects unusual peaks of current and shuts the device off when such an event occurs. Usually, it means that the two hot wires somehow come into contact, and this will lead to rapid overheating if not protected with a short-circuit breaker. Events like these usually happen when the cables are damaged by a metal object.

A residual current protection device measures the current flowing through each of the wires. In normal circumstances, they are equal. If one of the wires gets damaged and starts to bleed electricity, the device cuts the power. We recommend the J1772 extension cord as a safer option.

Safety Tip
Use a heavy duty cord
Do NOT connect EVSE or larger items requiring more electricity than provided by typical extension cords (14/16/18 AWG) — these items should either be plugged directly into a wall outlet with a heavy-duty electrical cord OR they should be plugged via an appropriate heavy-duty outdoor extension cord (10 AWG for NEMA 5-15/5-20).

Does cord length affect charging speed?

Yes, but not substantially. Just like a long garden hose – every foot adds a bit to the friction and lowers the water pressure at the end of the hose. Similarly, In electrical engineering terms the resistance increases with length, this lowers the voltage (electrical pressure) and less comes out the other end. 

For example, 25  feet of #8-gauge or #6-gauge wire will cause a voltage drop of about 1 percent if the supplied voltage is 120 volts and the wire carries no more than 50 amps.

How long does it take to charge an electric vehicle using an extension cord?

  40 Amp EV charger 32 Amp EV charger 16 Amp EV charger
Tesla Model 3 4 h 52 min 4 h 52 min 9 h 52 min
Nissan Leaf • 40 kWh 4 h 33 min 4 h 33 min 7 h 54 min
Chevy Bolt 5 h 5 min 6 h 20 min 12 h 50 min

Another electric car? Using a calculator and make a calculation using your data.

Safety Tip
Turn it off when not in use
Unplug appliances when not in use, especially if you are leaving the house for an extended period of time.
Safety Tip
Think about source wiring
When leaving a room, turn off all lights and unused electrical appliances. This may reduce the load on the electrical wiring.

FAQ

What EV charging cable extensions are suitable for Tesla?

A NEMA 14-50 extension cord will be suitable for use with the Mobile Connector (portable charger) and plug-in Tesla Wall Connector gen 2. Extension cables are not yet available for the Tesla Wall Connector gen 3 (hardwired stationary charger). There is an option to use the J1772 extension cord, which you can read about below.

Will the J1772 extender cable fit as a Tesla extension cord?

You can use a stationary or portable charger for non-tesla vehicles at home. Each Tesla comes with an adapter for this purpose. So a non-Tesla charger + J1772 extension cord + adapter will be able to charge your Tesla.

Which extension cord should you use: a 10-gauge or a 12-gauge?

The gauge of 12GA is larger, but the difference between the two gauges is minor. 12 AWG extension cords will suffice for most devices. Lawnmowers, heavy equipment, and other power-consuming appliances require a lower gauge, such as a 10AWG. The gauge tells you how thick the cord is. Keep in mind that the lower the gauge, the thicker the wire.

What is the maximum length of an extension cord that may be used?

Extension cords should not be more than 100 feet long. Moreover, for the NEMA 14-50, you will often only find 50-foot lengths on the market. J1772 cables are usually even shorter, at 40 feet. The maximum length of an extension cord may be exceeded by adding one extension cord into another. If the work is more than 100 feet long, a temporary power distribution box is necessary for NEMA.

Can I use an extension cord with the Level 1 charger?

Technically, yes, and you will need a 5-15 extension cord with a maximum load to do so. As with other chargers, EVSE manufacturers do not recommend an extension cord. However, user practice says that it is possible if safety rules are followed.

Why won’t my Tesla charge through an extension cord?

The Tesla probably can’t detect a ground connection. If your outlet is serviceable, make sure you are using a 3-prong grounded outlet and your extension cord has 3 prong. We’ve prepared a list here of tested and certified cables that are specifically compatible with the Tesla Mobile Connector.

What is the AWG of the extension cord for the Tesla Wall Connector?

We recommend the 10-AWG extension cords, we’ve selected for you in this review.

How do I protect EV extension cord from theft?

Blocking the cable with an electric car is, unfortunately, easily circumvented by criminals. Using a padlock is the most secure. Put a padlock on the lid of the inlet with the cable through the shackle if you want extra security. There are other ways, such as running the wheel over the cable or pinning it down.

Our Top Pick

Chargers that come with the vehicle are not always long enough to reach your parking spot. If you are a Tesla owner, along with connecting the Mobile Connector to a NEMA 14-50 outlet, a Camco extension cable would be a great choice.

The best solution for that problem is the LECTRON J1772 extension cable over NEMA extension cable because it offers excellent safety features and is more weather resistant. The cons of the J1772 is a the slightly higher price and weight but is considered a more proper and safer solution because it is designed specifically for EV charging. Even when manufacturers follow the same standards, the quality, materials and workmanship vary. The best is to choose a product that is tested by a third party.

The NEMA 14-50 connector will also get the job done and is considered a reasonably safe option. When you need to charge infrequently and the cable needs to be used to power other appliances, then NEMA extension cable should be your first choice. This standard is not designed for EV charging, therefore overheating and tripping the ground fault circuit interceptor can occur.

Electricity can be dangerous. Have you ever worried about the safety of charging an electric vehicle with extension cables? It can be done wrong, and you can also buy the wrong EV extension cord that does not fit your situation. Most chargers come with a 16-foot cable, which is not long enough for many users. This article is for every EV owner who happens to have their electrical outlet or a charger farther away than ideal. Here you can find all the info you need to get the purchase right extension the first time.

Mike Becker
About Mike Becker Linked In
Mike is a seasoned engineer with 10+ years of experience in charging systems. He bought a Tesla Model S in 2014 and has been in love with EVs ever since. He runs a small EVSE installation business in Florida and blogs about what he loves.

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