Why are extension cords not recommended for charging?

Hi there,

Newbie here with what is probably a stupid question. Can someone please explain in non-technical terms what is the issue with using an extension cord for LV1 charging? I'm talking regular ext. cords that you could buy at Lowe's or Home Depot.

As long as such a cord is rated for the 110V/ 20 amp charge, it should theoretically hold the charge without overheating or melting. At least this would be my first impression.

Yet on this site I have seen multiple users advise new Leaf drivers NOT to use extension cords. Do all the cords used for LV1 charging have to be specially rated for EV use?

thanks,

There are multiple topics on this - please do a search. The short answer is that they can work, but that they increase the risks associated with plugging in to charge, and defeat the temp sensor in the EVSE.

I think its that even a 110v charge will pull a significant amount of constant power from the wall. I think its just that they don't trust the extension cord to be of the appropriate quality or gauge for that draw, or that you may use some ridiculous length cord that would change the gauge requirements of the wire.

In "non-technical" terms it's because the risk of a fire/electrocution is increased. But if you're smart about it using an extension cord is fine. I've never heard of an extension cord being "specially rated" for EV use, but the key thing you've got to look at is the wire gauge. If your extension cord has 12 gauge wire and is in good condition, and plugs in securely to a good wall outlet, you're fine. If you're going longer than ~50 feet I'd suggest considering moving up to a 10 gauge cord.

That's half of it. The other half is that the number of plugs in sockets doubles, and the quality of extension cord plugs and sockets is much more variable than that of EVSE plugs and hardwired outlets.

Easier to prohibit than to list every condition that must be met to be safe.
Not a big deal... you are just on your own.

http://www.amazon.com/dp/B01BE8WIBU

starfuryomega: Get a single strand from an extension cord, say 6 inches or so. Bend it into the shape of an arc of a circle of about 6 inches in diameter. Then straighten it. Then bend it again the same way, and then straighten again. Keep repeating this, counting each repetition, until the strand breaks in half. I haven't done this myself, but I expect the total repetitions to be less than 100 or 2. Even before it breaks, I'm pretty sure the average cross-sectional area of the strand decreases -- causing the strand's electrical resistance to increase.

So thinking about how this affects an entire extension cord: As strands weaken -- and especially if they begin to break -- the voltage drop across the entire cord increases over time (in the form of heat which can begin to cause the insulation to harden and eventually crack -- and in the extreme case cause arcing at very high temperature) and correspondingly decreases the voltage to whatever is plugged into the extension cord.

Damage to the cord's wire strands can also occur in a number of other different ways, yet the outside of the cord may look OK, so it is difficult to know when to discard the extension cord before it becomes dangerous to use.

From one source on the internet: "About 3,300 residential fires originate in extension cords each year, killing 50 people and injuring about 270 others." and "CPSC estimates that each year, about 4,000 injuries associated with electric extension cords are treated in hospital emergency rooms. 50% of these injuries involve fractures, lacerations, contusions, or sprains from people tripping over extension cords. 13% of these injuries involve children less than five years of age; electrical burns to the mouth accounted for 50% of the injuries to young children.".

Hope this helps some...

So buy a new one... 10 gauge.

I use 10 gauge from Harbor Freight.

Evoforce said:

I use 10 gauge from Harbor Freight.

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You couldn't find one at the dump? because that's the next step below (?) Harbor Freight. Sure they make a few things that last as long as more expensive versions. I wouldn't count on a Chinese extension cord being one of them.

LeftieBiker said:

Evoforce said:

I use 10 gauge from Harbor Freight.

Click to expand...

You couldn't find one at the dump? because that's the next step below (?) Harbor Freight. Sure they make a few things that last as long as more expensive versions. I wouldn't count on a Chinese extension cord being one of them.

Click to expand...

I run very heavy duty equipment with my construction company and partnered automotive business using these cords. If you had done it you would rely on them. Don't take my word for it though, you seem to somehow be an authority. You can't knock the Chinese on everything. I'll bet you , like many of us, own plenty of things manufactured from there... like it or not. You ever heard the saying; Don't knock it until you tried it? These cords would be one of those cases Leftie.

I'm not normally a fan of "orange" extension cords(preferring blue or yellow) as they are generally vinyl and tend to get very stiff as the temperatures drop but this one does say "Maximum flexibility in even the coldest weather" and $68 shipped for 50' 10 gauge seems to be a good price now days.
http://www.amazon.com/Century-Contractor-Grade-Gauge-Extension/dp/B000BMDQHQ/ref=sr_1_2?s=hi&ie=UTF8&qid=1454966378&sr=1-2&keywords=extension+cord+10+gauge
I just found a yellow 50' 10 gauge that looks to be even cheaper at $60 shipped, thats more the price I remember. The reviews state it's rather "stiff" but I think thats more related to the fact that it's 10 gauge, several of the reviewers are using for EV charging.
http://www.amazon.com/XtremepowerUS-Extension-Electricity-approval-Current/dp/B00GXPWVXK/ref=sr_1_7?s=hi&ie=UTF8&qid=1454966731&sr=1-7&keywords=extension+cord+10+gauge
Note I couldn't get a link directly to the 50' 10 gauge cord, you have to select that option from the various extension cords in my link.

I run very heavy duty equipment with my construction company and partnered automotive business using these cords. If you had done it you would rely on them. Don't take my word for it though, you seem to somehow be an authority. You can't knock the Chinese on everything. I'll bet you , like many of us, own plenty of things manufactured from there... like it or not. You ever heard the saying; Don't knock it until you tried it? These cords would be one of those cases Leftie.

Click to expand...

In the case of cords made in China by reputable brand name companies, I'd at least consider one in a pinch. However, no-name cords made for a retailer who specializes in Cheap don't strike me as a good risk. They have to use cheaper materials to compete on wholesale price. I have little doubt they will generally work fine for a while, but I'd be very surprised if they compared in quality with the better cords made in the US, Mexico, or even Indonesia or Thailand. So while I wouldn't bet my meager savings that one will fail within the first year of heavier use, I also wouldn't recommend them to someone looking to charge an EV with one.

jjeff said:

Note I couldn't get a link directly to the 50' 10 gauge cord, you have to select that option from the various extension cords in my link.

Click to expand...

You want this URL:
XtremepowerUS Extension Power Electricity Cord Copper Wire UL approval 125V, 15Amp Current Cable W/Clear Plug (50ft 10Gauge), $59.95

garsh said:

jjeff said:

Note I couldn't get a link directly to the 50' 10 gauge cord, you have to select that option from the various extension cords in my link.

Click to expand...

You want this URL:
XtremepowerUS Extension Power Electricity Cord Copper Wire UL approval 125V, 15Amp Current Cable W/Clear Plug (50ft 10Gauge), $59.95

Click to expand...

No matter what I tried I could only get the link to the default page, from where one would select the various lengths, thanks
Also note to the OP, I have no personal experience with any of these extension cords I was just giving a few links to something that seemed like a good price and might work), best to read reviews and make your own educated choice.

LeftieBiker said:

I run very heavy duty equipment with my construction company and partnered automotive business using these cords. If you had done it you would rely on them. Don't take my word for it though, you seem to somehow be an authority. You can't knock the Chinese on everything. I'll bet you , like many of us, own plenty of things manufactured from there... like it or not. You ever heard the saying; Don't knock it until you tried it? These cords would be one of those cases Leftie.

Click to expand...

In the case of cords made in China by reputable brand name companies, I'd at least consider one in a pinch. However, no-name cords made for a retailer who specializes in Cheap don't strike me as a good risk. They have to use cheaper materials to compete on wholesale price. I have little doubt they will generally work fine for a while, but I'd be very surprised if they compared in quality with the better cords made in the US, Mexico, or even Indonesia or Thailand. So while I wouldn't bet my meager savings that one will fail within the first year of heavier use, I also wouldn't recommend them to someone looking to charge an EV with one.

Click to expand...

Harbor Freight stuff is good if you accept that they are disposable. I've bought a few things from them, and let's just say "high quality" is not the term that came to mind. But their stuff is cheap, and for a project where you need a tool that you are unlikely to use again in the future, they're great. Or for things like gloves where you don't expect them to last long anyway; just expect to replace the Harbor Freight ones more frequently than say, Wells Lamont. Plus the fit on some of them puts the term "fits like a glove" to shame, because they feel more like oven mitts.

I would NEVER trust anything electrical from them. A decent quality name-brand extension cord isn't that much more expensive, and certainly a lot cheaper than the potential losses from a fire...

RonDawg said:

LeftieBiker said:

I run very heavy duty equipment with my construction company and partnered automotive business using these cords. If you had done it you would rely on them. Don't take my word for it though, you seem to somehow be an authority. You can't knock the Chinese on everything. I'll bet you , like many of us, own plenty of things manufactured from there... like it or not. You ever heard the saying; Don't knock it until you tried it? These cords would be one of those cases Leftie.

Click to expand...

In the case of cords made in China by reputable brand name companies, I'd at least consider one in a pinch. However, no-name cords made for a retailer who specializes in Cheap don't strike me as a good risk. They have to use cheaper materials to compete on wholesale price. I have little doubt they will generally work fine for a while, but I'd be very surprised if they compared in quality with the better cords made in the US, Mexico, or even Indonesia or Thailand. So while I wouldn't bet my meager savings that one will fail within the first year of heavier use, I also wouldn't recommend them to someone looking to charge an EV with one.

Click to expand...

Harbor Freight stuff is good if you accept that they are disposable. I've bought a few things from them, and let's just say "high quality" is not the term that came to mind. But their stuff is cheap, and for a project where you need a tool that you are unlikely to use again in the future, they're great. Or for things like gloves where you don't expect them to last long anyway; just expect to replace the Harbor Freight ones more frequently than say, Wells Lamont. Plus the fit on some of them puts the term "fits like a glove" to shame, because they feel more like oven mitts.

I would NEVER trust anything electrical from them. A decent quality name-brand extension cord isn't that much more expensive, and certainly a lot cheaper than the potential losses from a fire...

Click to expand...

Again someone who has no experience with their 10 gauge extension cords trying to give advice on what they don't KNOW. Speculation on your behalf. They have been tried and true for me and I have lots of experience with their 10 Gauge cords operating under continuous loads. Anyone who buys from HF knows that plenty of their stuff is not quality and some is downright junk. I personally do get frustrated with a lot of poor quality equipment that is coming out of China. In the end, the fact still remains that we don't KNOW what the underlying problems exist for the poster at large.

jjeff said:

garsh said:

jjeff said:

Note I couldn't get a link directly to the 50' 10 gauge cord, you have to select that option from the various extension cords in my link.

Click to expand...

You want this URL:
XtremepowerUS Extension Power Electricity Cord Copper Wire UL approval 125V, 15Amp Current Cable W/Clear Plug (50ft 10Gauge), $59.95

Click to expand...

No matter what I tried I could only get the link to the default page, from where one would select the various lengths, thanks
Also note to the OP, I have no personal experience with any of these extension cords I was just giving a few links to something that seemed like a good price and might work), best to read reviews and make your own educated choice.

Click to expand...

These cords are listed as made in the USA or China.

Evoforce said:

Again someone who has no experience with their 10 gauge extension cords trying to give advice on what they don't KNOW. Speculation on your behalf.

Click to expand...

I'd rather speculate and assume their stuff is crap, than speculate and assume their stuff won't hurt me or burn my property to the ground.