21ft 40amp J1772 EV Extension Cord, Made in USA for Electric Vehicle Charging Stations, Carrying Bag, Ultra-Flex Cable, UL Listed Parts

I was a little skeptical of this cable based on the mixed reviews and online searching generally being against J1772 extensions, but the cable has been working for my needs so far, which is occasional use when I can't get close enough to my charger.Generally I can park within reach of my Wallbox and avoid using this. But in spring/winter when I have other things parked on the driveway and I can't get close enough, I will pull this cable out. It has never given any troubles with the car or charger, doesn't get hot to the touch, and feels solidly built. So full marks.One caveat is that I haven't used it at 40A. My Wallbox is normally set for 40A, but based on the other reviews, when I'm using this cable I lower it to 32A output. If your charger doesn't support easily adjustable output amperage, you may want to go for the 48A cable.

I purchased the 48 amp extension. It is made of #8 (or 8 AWG) wire. This is the same size as the cable used on a 48A Clipper Creek charger. A 40A Clipper Creek charger uses #10 (or 10 AWG), which lines up with the 40A extension sold by Inteset. I've only used the cable once at 24A so far, but it worked flawlessly. The terminations look professional, and the bag is a nice touch. The cable itself is heavy but flexible and has no memory issues (it does not curl up on its own when stretched out). It came with a label zip tied to the cable that indicates the maximum size charger to use. I plan on leaving that attached as a reminder.As an emergency extender this cable seems to be the best choice. I purchased a 50A extension cord that would go between the charger and socket, but realized that only works with a 14-50 receptacle. This 48A extension will work with whatever charger is available and at L2 or L1 charge rates. I purchased the 48A version as that is the highest charge rate my Mustang Mach E will accept. So I can use this extension with higher rated chargers as the car will limit the current to 48A, which happens to be the rating of this cable.I want to include some information on the NEC (NFPA 70) and the rating of this cable. These reviews had me really concerned as I do not want to burn down my house! However, people are attempting to apply building code to the size of this cable. That is not appropriate. For anyone interested please refer to NEC, 2023 revision, section 625.17(B), pg 559: the NEC does not specify the size of the cable between the charger (EVSE) and the vehicle, they leave that to UL. There are NEC specifications (625.17(A)(2) pg 559) for the cable between the charger and the receptacle (or electrical box that connects to the building wiring) but that references the 'flexible cord' tables 400.4, 400.5(A)(1), and 400.5(A)(2) on pages 287 and 288. Those tables do NOT use the 80% rule; probably because these cables are not to be placed inside walls, use different insulation, etc. As these tables should not be applied to this extension I included what size of cable 40A and 48A chargers use which is #10 and #8 respectively and is the same size as the cables offered by Inteset. This would be a safe check when using the extension... if the charger cable is smaller or the same size as the extension (per label on the side of the cable, not the diameter of the cable) then you're good to go! Also, wire size is backwards: #8 is bigger than #10, which is bigger than #12, etc.

After getting a second EV I needed to be able to reach the rear of my garage for charging. Unfortunately I had positioned my charger where it was convenient to reach the first car but not the back. This product completely solves that problem. Have used it numerous times since purchase and not encountered any of the reported issues from other reviews (fraying of plastic cover at junction to connectors, damage to connector port). Works perfectly with Tesla adapter and running 32A charger. This product is a little more expensive than some others advertised on Amazon but since it is made in the USA I figured there is probably better product QA/QC than other cheaper products. A little more important since you're working with something that's hooking up to your car and electrical system.Would definitely purchase again if necessary.

Updated Review:This extension uses small 10 gauge wire but apparently it's too small for 40 amp charging. For 40 amp charging it should have 8 gauge wire. I have a 240v 40 amp charger on a 50 amp breaker. After using this extension for about two months and having two separate chargers failures my electrician tested my wiring and connections and ruled this extension cable was causing too much resistance due to the small gauge wires. The electrician said reducing the charging rate to 32 amps would be fine for this cable but at 40 amps the two chargers kept faulting and after removing this cable all issues resolved.Old Review: Could have been great. Works exactly as described and 40 amp charging is consistent and reliable. However the casing and wires are prone to twisting. I have a home charging unit and the wires and casing are thick enough and sturdy enough not to twist up. You can easily wrap up the cable. This extension is harder to coil up as it twists up and you have to take more time to wrap it up. Otherwise it's a good deal and works well.

I googled a bunch of sellers on Amazon to get more info about products before buying a home charging cable extender for my Ford Lightning truck. I have to park outside and my outlet is in my garage, so I needed an extender cable that was legit.This company has their own website but sells through Amazon. The products are manufactured in the USA and they’re UL certified, unlike a lot of other products on the market.The cable is thick and sturdy, the connectors on both ends are secure and well made. I have been running the cable under my garage door to my driveway to charge my vehicle for about a month and it’s been much better than a standard extension cable, no noticeable heat from the cord or any other issues with charging. It has been raining a lot and the connection is clearly water-tight.I will absolutely buy more products from this manufacturer in the future, and I hope they create additional products (such as charging adapters) in the future.