15A extend cord for charging at 110V is ok?

Hi I'm so new in this EV world, in fact, I'll pick up my LEAF tomorrow.
Before I move to a house with garage, I'll have to park the leaf 30ft from the outlet on wall. So I need an extend cord on the road from sell to home.
Here's my question: Can I go to Walmart to buy a 15A extend cord is it strong enough?

Thanks very much!

wijj said:

Hi I'm so new in this EV world, in fact, I'll pick up my LEAF tomorrow.
Before I move to a house with garage, I'll have to park the leaf 30ft from the outlet on wall. So I need an extend cord on the road from sell to home.
Here's my question: Can I go to Walmart to buy a 15A extend cord is it strong enough?

Thanks very much!

Click to expand...

I would not use a 15A cable @ 12A for 8 hours, it might melt something. Better to use a 20A cable that won't get as warm. Either way, don't cheap out, go to a Home store or electrical supply house and get a good quality cable, with heavy-duty ends. You will be on your own if the Wally cable catches fire, since practically every EV maker says NO to extension cords.

Also get the shortest cable that will reach, less heat loss.

What I did was go to home depot and buy 10 gauge rubber jacketed cable. 10-3 SO in the exact length I needed, along with their best screw on nylon connectors. I can inspect the wire every once in awhile and re-tighten if necessary.

Also, make sure the outlet you plan on using is up to snuff. Make sure there are no other loads connected to the same breaker. (My garage has one 20A breaker for the 4 outlets, the garage door opener, and the heater, which I thought was a lot, but later I found that my office was also on that same 20A breaker. (Did not figure that out till an electric drill took out a computer.) Get an electrician to inspect it before doing more than a trickle charge, and keep an eye on it to be sure it is not getting hot. I always just put a new, high quality outlet on and sleep better. I actually added a sub-panel for a 240V EVSE and 2 dedicated 20A 120V outlets. One with a line filter for tools, and one for the stock EVSE, just in case the 240V AV goes out. (3 years, still running, way to go Nissan!)

wijj said:

Hi I'm so new in this EV world, in fact, I'll pick up my LEAF tomorrow.
Before I move to a house with garage, I'll have to park the leaf 30ft from the outlet on wall. So I need an extend cord on the road from sell to home.
Here's my question: Can I go to Walmart to buy a 15A extend cord is it strong enough?

Thanks very much!

Click to expand...

Personally I went the opposite route of Volt3939. I went to home depot and bought a 10/3 extension cord, 100ft in length that was pre-built. Sometimes I only need 3ft so that nobody trips on my L1 charge cable, sometimes 80ft so I can loop it around trees and shrubs out of people's way if I am ICE'd.

But it is high quality, the Vdrop is not bad and it is rated for 20A continuous. General rule of thumb is do not load a circuit more than 80% continuous. Idea being a hair dryer and toaster take a lot of power, but you don't run your hair dryer or toaster 24/7. The Leaf is like a toaster that is on for 20 hours charging.

Here is the one I got: http://www.homedepot.com/p/YELLOW-JACKET-100-ft-10-3-SJTW-Extension-Cord-with-Lighted-T-Blade-2992/204667728?N=5yc1vZc4neZ2bcpq6Z2bcpq7Z1z0u3feZ1z11vjbZ1z11wfrZ1z11yyo" onclick="window.open(this.href);return false;

Don't go cheap!
There is a thread about an extension cord FIRE with a cheap cable.
Also don't leave a bunch of it in a big wad, that can also cause overheating.

And don't place a floor mat over any part of it to prevent tripping.
Try to place it in a way that there won't be much need for movement.
Every time you move that cord, you will place stress on the strands, which is why it's always better to have a permanent installation over an extension cord; no movement to break down the wires.

Good Luck!

Thanks very much for all of you, volt3939, 2k1taoster, timlee& foolios! I understand the principal now. More security! Thanks!

10AWG is definitely a good option. Especially if you're going to do a 100ft run.
If you only need 30', 12GA should be enough.

Under absolutely no circumstances should you use 14 or smaller to charge any EV. As mentioned, this is a huge safety issue, and is the main reason the handbook says to not use an extension cord. Because outlets are required to meet specific electrical, thermal, and other regulations, they can reasonably be assumed to be safe to use. Adding an extension cord, even 3', could make the circuit too long, and violate NEC or other safety regulations.

The reason 10GA is recommended is because it is much larger than the wiring in the walls (which is usually 14ga for a standard 120/15 outlet), and helps to compensate for being at the end of a long circuit. 12GA is still larger than the wall wiring, but the wall wiring is also rated differently.

A similar case is when jumping cables, #2 or #4 should be used for jumping most cars. Don't buy those silly #12 jumper cables. They tend to… melt.

#12 wire is fine. The 20a cord above may not plug into your outlet unless it is a NEMA 5-20 with the T slot on the neutral.
Check the connectors for excess heat at 20 minutes and 60 minutes.
Keep the wire uncoiled so it does not retain heat.

There is lots of great advice already given.

If you will be using the same garage outlet for charging all of the time, make sure that's a quality outlet. Outlets have metal prongs with springiness. With use, they wear out and the springs lose tension, leading to higher resistance and heat. I had this problem and noticed it by the outlet getting quite warm. I replaced the outlet with a higher quality outlet and have not had the problem since. Better outlets are most often built better and will last much longer.

You can also judge for yourself if something is wrong. Just feel for heat. The plug, jack, and wire should not be noticeably hot when you first plug it in and should not heat up much after 8 hours of charging. Yes, it will be a few degrees hotter than outside air, depending on the wire size and quality of the connectors. But real problems should be obvious from a feel-test.

Bob

The few times I have charged at 120V I used a 50 ft #12 cable from Costco. It worked fine with no overheating. I sure missed my L2 charger though.

Under absolutely no circumstances should you use 14 or smaller to charge any EV. As mentioned, this is a huge safety issue, and is the main reason the handbook says to not use an extension cord. Because outlets are required to meet specific electrical, thermal, and other regulations, they can reasonably be assumed to be safe to use. Adding an extension cord, even 3', could make the circuit too long, and violate NEC or other safety regulations.

Click to expand...

I think you have the emphasis a bit wrong, here. It is almost always the plug end on the extension cord, or the outlet, that overheats, not the actual cable. I agree that 14 gauge isn't wise, but the condition of the plug and outlet is of more concern. 14 gauge cables are usually rated for 1500-1800 watts, which is enough, at least at the higher end, for casual charging.

LeftieBiker said:

Under absolutely no circumstances should you use 14 or smaller to charge any EV. As mentioned, this is a huge safety issue, and is the main reason the handbook says to not use an extension cord. Because outlets are required to meet specific electrical, thermal, and other regulations, they can reasonably be assumed to be safe to use. Adding an extension cord, even 3', could make the circuit too long, and violate NEC or other safety regulations.

Click to expand...

I think you have the emphasis a bit wrong, here. It is almost always the plug end on the extension cord, or the outlet, that overheats, not the actual cable. I agree that 14 gauge isn't wise, but the condition of the plug and outlet is of more concern. 14 gauge cables are usually rated for 1500-1800 watts, which is enough, at least at the higher end, for casual charging.

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Maybe… but calculate the vdrop for a 12A load on a 200' circuit over #14 wire. Losses are quite huge. #10 has about 1/3 the vdrop as #14.

The plug mostly heats up because of poor/small contacts. This is mostly why high amp circuits (think L14-50) are huge compared to 15/20A outlets.

I think both are a consideration, but considering a plug is going to be connected somewhere, might as well do what you can to make sure the wire itself isn't an additional problem.

200' leads are kind of unusual, as are 200' 15 amp circuits. Yes, worn outlets and plugs are the main issue.

LeftieBiker said:

200' leads are kind of unusual, as are 200' 15 amp circuits. Yes, worn outlets and plugs are the main issue.

Click to expand...

With a 100' extension cable, I wouldn't be surprised if a circuit hit 200'. Sure, it's probably not even 50% of the cases out there. The vdrop over 100' is still huge with #14 wiring. Ideally, you want the vdrop under 3%.

Bob said:

If you will be using the same garage outlet for charging all of the time, make sure that's a quality outlet. Outlets have metal prongs with springiness. With use, they wear out and the springs lose tension, leading to higher resistance and heat. I had this problem and noticed it by the outlet getting quite warm. I replaced the outlet with a higher quality outlet and have not had the problem since. Better outlets are most often built better and will last much longer.

Click to expand...

On the other hand, if you will be using other outlets, using an extension cord is a real bad idea. When you pick up the leaf, read the sheet of instructions packed with the 120 volt charger. Note that it says to not use extension cords.
The current EVSE has a temperature sensor - that same sheet tells you the error code when it decides the socket is too hot. If you use an extension cord, it cannot tell if the wall socket has gotten hot.

Bob said:

You can also judge for yourself if something is wrong. Just feel for heat. The plug, jack, and wire should not be noticeably hot when you first plug it in and should not heat up much after 8 hours of charging. Yes, it will be a few degrees hotter than outside air, depending on the wire size and quality of the connectors. But real problems should be obvious from a feel-test.

Click to expand...

Indeed, give the plug at the wall the feel test. Many outlets in service are fairly light duty, or a bit old and worn, and don't do well with continuous high loads. I thought the extension cord was ok with a #12 cord wire, but it still got hot - the heavy cord doesn't make the outlet better. It also seemed to be getting warmer after a few days of use (even without unplugging or replugging the cord). It motivated me to switch to a L2 charger much sooner than I had planned.

Other threads discuss the various grades of outlets, and the benefits of better outlets with better (more solid) wire connections (instead of push in on the back), and use of heavier wire for 20 amp circuits and outlets. Someone even posted pictures of the remains of the fire caused by overheating when charging. You don't want to do that!

Alan