EV Extension Cable vs Buying a Charger With a Longer Cable
Short answer
An extension cable adds two connection points to a circuit carrying a heavy continuous load, and most charger manufacturers advise against using one. A charger supplied with a longer cable has one continuous conductor from the unit to the car and is engineered as a whole. If the cable will not reach, the better fixes are a longer factory cable or mounting the unit somewhere else.
At a glance
| BESENERGY EV charger extension cable, 40 A, 20 ft | Autel 50 A hardwired charger, 25 ft cable | |
|---|---|---|
| Extra connection points | Two | None |
| Manufacturer position | Generally advised against | Supported |
| Warranty implications | Possible, check the terms | None |
| Weather exposure of connections | Yes, at both joints | No |
| Cost | Lower | Higher |
| Better alternative | Reposition the charger | Not applicable |
Choose the BESENERGY EV charger extension cable, 40 A, 20 ft if…
Use an extension only as a temporary measure, with a cable rated for the full current, kept off the ground and out of standing water, and inspected regularly for heat or damage at the connections. Check your charger's manual, since many state plainly that extensions are not permitted and using one may affect the warranty. It is a compromise rather than a solution.
Check BESENERGY EV charger extension cable, 40 A, 20 ft on Amazon
Choose the Autel 50 A hardwired charger, 25 ft cable if…
Buy a charger with the cable length you need, or have the unit mounted where a standard cable reaches. Twenty five feet covers most garage layouts, and moving the mounting position during installation costs far less than working around it forever. Measure the actual route to the charge port, on the side the car will be parked, before deciding what length you need.
Check Autel 50 A hardwired charger, 25 ft cable on Amazon
Related
- Electrical safety and what needs an electrician
- Home EV charger installation guide
- Installation cost calculator
Comparison based on published manufacturer specifications and the general consensus of owner reports. We have not tested these products side by side. Confirm current specifications and prices before buying. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.
We review them on their own too, in full detail: the Autel MaxiCharger and its 25 foot cable and the Leviton, whose cable is 18 feet.
Common questions
Why are extension cables discouraged?
Because every connection is a point of resistance and heat, and this circuit runs at full load for hours. Two additional connections sitting on a garage floor, potentially in water, is a meaningful change to the risk profile. Manufacturers exclude them for the same reason they specify the cable they supply.
What length of cable do I actually need?
Measure the path the cable will really take, from the intended mounting point, around the car, to the charge port. Cables do not travel in straight lines and they do not stretch. Most people need less than they fear if the charger is mounted thoughtfully, and more than they expect if it is mounted where the panel happens to be.
Can the charger be mounted outside instead?
Often yes, with a unit rated for outdoor use and an installation designed for the location. That can be far cheaper than solving a reach problem with cable. Outdoor installations have their own requirements for enclosure rating, mounting height and weather protection, and your electrician will handle those.
Does a longer cable reduce charging speed?
Not measurably at these lengths, since the cable is sized for the current it carries. Voltage drop matters over the fixed wiring run from the panel, which is far longer, and that is accounted for in the conductor sizing. The voltage drop calculator on this site covers the fixed run rather than the charging cable.
Getting your own panel and load numbers ready for an electrician? The EV Home Charging Install Planner is the paid version of these pages: 8 printable worksheets you fill in with your own numbers, plus the full PDF, $29.
How this page was researched
Specifications come from manufacturer documentation, listed safety certifications and verified owner reviews. We do not perform hands-on product testing and never claim to. Figures are researched planning information, not professional electrical advice. Last reviewed 2026-08-17.