Anyone know if it safe to charge via 220v extension cord?

[macgyver60]

We have an emergency generator because we lose power 1-2 times a year and with Sandy years ago we were out for two weeks. The problem is the generator was installed before we had an EV and the EV plug is not on the panel that is powered by the generator. I could reach a powered 220v outlet with the portable charger and a 20 foot extension cord but wondering if this is safe. There do seem to be such cords designed for Tesla.

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[Phil-Springs]

Possible but I’d avoid it. Make sure the extension cord is rated to handle amperage of the circuit you plug it into.

 

[bshaw]

Without more information about the extension cord you plan on using, it’s impossible to answer your question of “is it safe?”

If you have something rated for amps the charger will be pulling, then it should be an ok temporary solution.

 

[HuntingPudel]

There are a couple of J1772 extension cords that can probably be trusted. I would not trust any cords on the mains side of the EVSE. ??

 

[glenthompson]

As long as the extension isn’t too long and is sized properly it shouldn’t be a problem. Extensions made for 50 amp RVs would work well but can be expensive. Here’s an example.

 

[Deleted member 9461]

Go for it, I made a welding extension cord, that wound up being used for the charger more. Also had a propane generator cause Hawaii power sucks (insert offensive piece) that I would charge with. Mine was a 50 footer. No power droop.

 

[generaltso]

As @HuntingPudel suggested, get a J1772 extension cable. They’re more versatile and are made for car charging.

 

[JamieGeek]

Like this? (J1772 extension cord)

 

[KevinS]

I agree with the J1772 extension cable advice; really good and weathertight connection that is least likely to expose the charger to the elements or damage. I keep one in my frunk and have used it several times, even in 120V situations where I want the charger up at the wall outlet.

 

[macgyver60]

Possible but I’d avoid it. Make sure the extension cord is rated to handle amperage of the circuit you plug it into.

This would only be used only in emergencies when we have a power outage that lasts more than a day or two so not a regular thing. After Sandy I always like to have a plan B and C

 

[macgyver60]

There are a couple of J1772 extension cords that can probably be trusted. I would not trust any cords on the mains side of the EVSE. ??

I'm curious. Why would the J1772 approach be better/safer than using something like this option which another person recommended on this thread (see below). I have no personal preference but I am not an electrician so just trying t learn.

https://www.campingworld.com/camco-power-grip-heavy-duty-extension-cord-30-ft.-50-amp-37814.html

 

[macgyver60]

As long as the extension isn’t too long and is sized properly it shouldn’t be a problem. Extensions made for 50 amp RVs would work well but can be expensive. Here’s an example.

Thanks. That looks like a solid opton

 

[Maquis]

I'm curious. Why would the J1772 approach be better/safer than using something like this option which another person recommended on this thread (see below). I have no personal preference but I am not an electrician so just trying t learn.

https://www.campingworld.com/camco-power-grip-heavy-duty-extension-cord-30-ft.-50-amp-37814.html

Because J1772 cords are made specifically for EV charging. They are (should be) designed knowing they will be used for continuous duty. Other extension cords may or may not withstand continuous, heavy use. Powering a camper or RV is nothing compared to EV charging.

That said, I would have no problem using a properly rated (over rated) cord on the mains side, especially given your infrequent use case. For example, I’d use the one you linked to with a 32A EVSE, but I’d probably not plug a 40A EVSE into it.

In any event, make sure the cord is not coiled up when in use, and keep an eye on how hot the connectors get, at least initially.

 

[VaporTrails]

This is where I really like the current-shaping features of a good EVSE. You can derate the consumed current to what your current setup is safely able to deliver. I would want to charge low and slow when the refrigerator and a room AC unit are my main problems. To the question at hand, I would not trust any store-bought supply-side extension cord, unless you further derated the consumed current to about half the listed spec on the cord.

 

[macgyver60]

Because J1772 cords are made specifically for EV charging. They are (should be) designed knowing they will be used for continuous duty. Other extension cords may or may not withstand continuous, heavy use. Powering a camper or RV is nothing compared to EV charging.

That said, I would have no problem using a properly rated (over rated) cord on the mains side, especially given your infrequent use case. For example, I’d use the one you linked to with a 32A EVSE, but I’d probably not plug a 40A EVSE into it.

In any event, make sure the cord is not coiled up when in use, and keep an eye on how hot the connectors get, at least initially.

Thank you for the explanation. That is very helpful. So even though the cord is rated for 50 amps you need to use it at a much lower amperage because its an EV. I would be using the MachE portable charger in these situations. Again, not really sold on one solution or the other although the J1772 cords seem to be about twice the price so for something that would get very infrequent use that might be a consideration.

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