heavy duty extension cord for emergency L1 charging?

[metricus]

The most important thing to remember when you "emergency charge" at an unknown/unverified source (friend, restaurant, business) is that if your adaptor is not properly grounded it will not work. The light comes on but it's not green but amber or whatever color.

The second thing is heat. I have seen all sorts of disasters in people's garages and mostly with outdoor GFCI receptacles. Remember that when you plug-in you are betting the well being of your adaptor on their good housekeeping habits.
If the receptacle is badly wired the possibility that it will melt your molded plug is high.
So having a heavy duty 1-2 ft cord that you TRUST on hand is a good idea even if you don't need extension. The cost outweighs having to replace your adaptor's plug.

Final advice: if you will truly emergency charge chances are you will use whatever is on hand. Use the shortest and beefiest extension cord possible. Once you get it to work don't walk away!. KEEP CHECKING the plug and extension cord periodically for excessive heat. "Jiggle" connections and ensure there is no sparking sound or flame. It is also possible that the breaker can trip while you sit for a beer in the kitchen waiting for your vehicle to charge.

Cheers.

[MikeD]

metricus: I applaud your attention to safety in your comments! I have a question, however, concerning the suggestion of using a short 1-2" cord to try to protect your EVSE's plug from the possibility of excessive heat. It is my understanding that the EVSE that Nissan provides for their Leafs (beginning 2013 MY, I think) has an "excessive heat" monitor in their plugs to safely discontinue charging when appropriate. Wouldn't using an extension cord for such EVSEs tend to defeat this safety feature? (BTW I don't know what other EVSEs have this.)

[Nubo]

metricus: I applaud your attention to safety in your comments! I have a question, however, concerning the suggestion of using a short 1-2" cord to try to protect your EVSE's plug from the possibility of excessive heat. It is my understanding that the EVSE that Nissan provides for their Leafs (beginning 2013 MY, I think) has an "excessive heat" monitor in their plugs to safely discontinue charging when appropriate. Wouldn't using an extension cord for such EVSEs tend to defeat this safety feature? (BTW I don't know what other EVSEs have this.)

That's a good point. Ideally you want to protect the outlet and building too

[Oilpan4]

When I got my leaf I started off using my 10 gauge SOO extension cord that I had been using on my welder, air compressor and plasma cutter for away charging. SOO 10 gauge cords are very bulky and heavy and complete over kill for 16 amp charging.
About this time last year I stated using STW 12 gauge cords for my 16 amp evse. I used one 12 gauge STW cord almost daily for around 10 months.
If you have 12 amp evse you can use a 14 gauge cord.

I have seen gfic receptacles over heat and fail spectacularly. Use a circuit protected by a gfic breaker.