EVSE and extension cords

[1969Camaro]

PSA- I found the Ford EVSE doesn't much care for extension cords on the 110V side. When I tried it with a 12G wire cord it worked fine. Not sure if its a resistance issue or grounding path. Suggest if you are planning a trip and need to use an extension cord try it out first before you leave.

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[Maquis]

I’ve used mine several times with a 12 gauge extension cord. The only time I had an issue was with a cord with an open ground wire. The lights on the FMC will tell you what the problem is (if any)!

 

[Mach-Lee]

True, owner's manual says you're not supposed to use an extension cord:

However if you absolutely must, you need to use a 14 gauge cord or larger, and limit the length to as short as possible. I carry 25' cord that I've load tested and verified to be safe.

 

[Maquis]

True, owner's manual says you're not supposed to use an extension cord:

However if you absolutely must, you need to use a 14 gauge cord or larger, and limit the length to as short as possible. I carry 25' cord that I've load tested and verified to be safe.

It’s a good thing electrons can’t read!

 

[ZuleMME]

Extension cords are just longer wires. Wires have resistance often measured in ohms per foot. If that resistance is too high (or the cord too long) the voltage drop will exceed what the charger in the car will happily use. At that point it'll fail. 110/120v is already quite low. You need a beefy cord and hopefully a shorter one. Then it'll work.

 

[Tyldum]

Extension cords are just longer wires. Wires have resistance often measured in ohms per foot. If that resistance is too high (or the cord too long) the voltage drop will exceed what the charger in the car will happily use. At that point it'll fail. 110/120v is already quite low. You need a beefy cord and hopefully a shorter one. Then it'll work.

Isn't the voltage drop for 120v for a 30 foot extension cord about 1%?

The fire hazard is comes from weakest link, so plugging anything between the EVSE and the socket is a liability as it could introduce a weak connection. And extension cords could be both under dimensioned and often coiled up leading to overheating.

Not an electrician by any means.

 

[1969Camaro]

Sometimes on a trip you (I) may have no other options which is why I bring an extension cord. The 12G wire can handle 20A continuous according to the MFG.

My last trip I needed about 10 ft additional to reach the nearest outlet.

 

[bshaw]

Agreed with above about getting #12 extension cord that is outdoor rated, and only the minimum distance necessary to reach the outlet.

I see why the disclaimer in the manual is written that way.... but the reality is that if you're scraping by to get a 120V charge into the car -- you may also be stretched on how close that 120V outlet is to the car, hence will often need to use the Ford Mobile EVSE in combo with an extension cord.

 

[SSnc]

Instead of an extension cord, I’ve had good success with using an EVSE extension cable such as this one:

Inteset 21ft 40amp J1772 EV Extension Cord, Made in USA - for Electric Vehicle Charging Stations, Carrying Bag, Ultra-Flex Cable, UL Listed Parts… (21 Feet) https://a.co/d/hldiQQC

I have only used it doing a 120V charge while traveling but it did work with my 32 amp charger at home when I briefly tested it.

 

[HuntingPudel]

Instead of an extension cord, I’ve had good success with using an EVSE extension cable such as this one:

Inteset 21ft 40amp J1772 EV Extension Cord, Made in USA - for Electric Vehicle Charging Stations, Carrying Bag, Ultra-Flex Cable, UL Listed Parts… (21 Feet) https://a.co/d/hldiQQC

I have only used it doing a 120V charge while traveling but it did work with my 32 amp charger at home when I briefly tested it.

You beat me to it! I was going to suggest a J1772 extension.

 

[bshaw]

Instead of an extension cord, I’ve had good success with using an EVSE extension cable such as this one:

Inteset 21ft 40amp J1772 EV Extension Cord, Made in USA - for Electric Vehicle Charging Stations, Carrying Bag, Ultra-Flex Cable, UL Listed Parts… (21 Feet) https://a.co/d/hldiQQC

I have only used it doing a 120V charge while traveling but it did work with my 32 amp charger at home when I briefly tested it.

More expensive, but probably worth it, since you will also be able to extend an L2/240V connection to reach your car. Even situations like where the parking at the public L2 charger is ICE'd, and you need more cable to reach another space.

 

[daemonic3]

I have used this handy wire resistance calculator many times (for doing circuit board power measurements) and it can come in handy in this case: https://www.inchcalculator.com/wire-gauge-size-and-resistance-calculator/

For example, select 14 AWG aluminum (worse than copper), and a 20' example comes to 0.0778Ω. If you pull 15A load that results in 15x0.0778 = 1.167V of drop through the cord. So your EVSE would see 1.167V less at the extension than the nominal 110-120V at the outlet. If your outlet was already closer to 110V than 120V, it may start to make the charger unhappy. 16 AWG is nearly twice as resistive so it would really start to add up!

 

[RickMachE]

Just used a 12 gauge cord for two days just fine.

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