Standard Extension Cord Charging

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ggodman

Well-known member
Joined
Aug 31, 2010
Messages
71
Location
Santa Clarita, CA
I've been using the included 110/120 charger to charge my car for a couple of days and it works but I was wondering if any of the smart people around here have thoughts on a way to add/design an accessory to plug in the car with a standard old extension cord. It's not really a huge problem to drag out the supplied charger but I would rather leave a $20 extension cord I bought at home depot at my workplace (not a high risk theft area but I'm not buying an extra $700 charger and leaving it there) and just be able to plug into it when I get there instead of having to open the hatch take out the charger, plug it in and then when I'm done put it back, etc. I'm wondering if there could be a takeoff from the J1772 or adapter or I don't know what. I followed Aptera for years and I liked the simple, hey plug it in with a cord idea for 110/220. Granted it would need to check for GFCI etc, I don't want to electrocute myself but if I'm doing level 1 anyway why do I need the giant brick. Based on Ingineer comments it only draws 12 amps for 110/120 (Sorry Ingineer if I misquoted) and it seems like Nissan has the best 110/120 charger but that also makes the brick attached to that charger huge, not to mention can anyone tell me why they decided you need a giant gun shaped connector (Yes I know it's a standard, that just means designed by committee right)?

Anyway I figure someone will figure this out eventually, I've seen the pilot signal thread etc, just want to stimulate discussion and would love to have a gadget like Ingineer upgrade for just easy 110 charging with a standard cord.
 
The connector is all about robustness and safety. Sorry.

An enterprising individual or company might invent an affordable "one piece" J1772 handle embedded EVSE that accepts a 120V extension cord. But I'm really not sure there is enough demand to justify the engineering necessary. And it would be even more convenient to steal. ;)

The fact is that full EV cars were designed to be charged primarily by private and public 240V. Get your work on-board. :)

--Ron
 
I don't know that we have all the facts nailed down yet, but it certainly appears that 120v charging is less efficient than 240v charging. You may not care at your workplace, but you probably do care how much electricity you buy at home to feed your LEAF. If, as seems likely, you could reduce your home charging cost by something like 12%, wouldn't that be worth spending some money up front?

I originally thought I was going to get by with 120v charging only, but I changed my mind and paid Ingineer for an upgraded unit. I'm glad I did. Note that I kept my original unit, included in the car, and got a new upgraded unit from him; which will indeed cost you more than $700. But on the house side you only need an L6-20 outlet. Mine might as well be permanently wired to that.

So, why am I going through all this? Because now you can cut your "drag out/plug/unplug/put away" events in half. Yes, you are still doing it at work, but not at home. In fact, you might not even need to charge at work if you can charge twice as fast at home.

But back to your dream, it's only a dream, and I expect it will stay that way. What almost certainly will happen is that 120v charging cords will come down in price. The EVSE in that big black brick is likely to get cheaper, and smaller, and lighter. It might even end up being integrated with the wall plug. The J1772 connector won't get much smaller or lighter, but it too is likely to get cheaper. So, it might in time seem like your dream has come true, though engineers will tell you it hasn't, really.

Ray
 
Aptera never made a commercial product but if they ever had competent people to do so it would have ended up with the same plug as the LEAF, standard cords are a poor idea for a multitude of reasons. If you are concerned about theft, use a good 12G cord and lock the EVSE or "charge plug" into the hood area, inside the car via the window, hatch or lock it using the supplied lock tabs, this is easy to do and there are many creative options. As a side note, it is technically not a charger in any way it is an EVSE or a "charging cord", the "charger" is in the car. If you want a more efficient portable option get your EVSE upgraded here: http://www.mynissanleaf.com/viewtopic.php?f=4&t=3625
 
One similar existing application that uses the ordinary extension cord is an engine block heater ( used in northern climes ). Seems like if that is not dangerous, this should also be possible. As a safety precaution, the vehicle electronics could sense if the voltage is dropping significantly, indicating a small gauge ( or very long ) extension cord in use. The current could be ramped up until the voltage drops to, say, 108V. And of course, a max of 12A would also be a limit. A quick calculation shows that 150ft of 18 AWG would still work, dissipating about 1 watt per foot. Any higher gauge cord would allow the full 12A of current and dissipate less than 1W/ft and drop less than 12V. A longer 18AWG cord would need the current reduced. I guess I don't see the safety concern. Also, right now anyone can add ( as I have ) an extension cord to the existing 120V EVSE, and as my calculations show there should be no safety issue. What am I missing?
 
mrggg said:
One similar existing application that uses the ordinary extension cord is an engine block heater ( used in northern climes ). Seems like if that is not dangerous, this should also be possible. As a safety precaution, the vehicle electronics could sense if the voltage is dropping significantly, indicating a small gauge ( or very long ) extension cord in use. The current could be ramped up until the voltage drops to, say, 108V. And of course, a max of 12A would also be a limit. A quick calculation shows that 150ft of 18 AWG would still work, dissipating about 1 watt per foot. Any higher gauge cord would allow the full 12A of current and dissipate less than 1W/ft and drop less than 12V. A longer 18AWG cord would need the current reduced. I guess I don't see the safety concern. Also, right now anyone can add ( as I have ) an extension cord to the existing 120V EVSE, and as my calculations show there should be no safety issue. What am I missing?

Yes it is and the connections can heat, oxidize and melt. This is how fires are started.
 
When I was in Alaska, I saw an awful lot of ragged looking block heater electric cords wrapped around radiator grills or flung in the back of pickups. Small villages and outside of city limits were pretty lax on electrical inspection too. I don't remember reading about fires from these cords which received much harsher treatment than Leaf charging cords.
Block heaters draw in the ballpark of 500-1000 watts, so not much different from standard L1. With the described mechanism for cutting off charge flow if voltage drops below 108 volts - one is looking at about 12 Amps x 20 volts = 240 watts -- about the heat generation of four 60-watt light bulbs.
Is the described system much different than where the L1 EVSE plugs into the wall?
 
2011RedLeaf said:
When I was in Alaska, I saw an awful lot of ragged looking block heater electric cords wrapped around radiator grills or flung in the back of pickups. Small villages and outside of city limits were pretty lax on electrical inspection too. I don't remember reading about fires from these cords which received much harsher treatment than Leaf charging cords.
Block heaters draw in the ballpark of 500-1000 watts, so not much different from standard L1. With the described mechanism for cutting off charge flow if voltage drops below 108 volts - one is looking at about 12 Amps x 20 volts = 240 watts -- about the heat generation of four 60-watt light bulbs.
Is the described system much different than where the L1 EVSE plugs into the wall?


LEAF draws 1440 watts. No one should use a L1 EVSE on even a 12G extension cord or anything other than a dedicated proper 120V outlet. Any attempt to imply this is remotely safe is reckless IMO and very irresponsible. There are so many more variables to consider in the real world and it's simply a bad practice to justify even indirectly.
 
2011RedLeaf said:
When I was in Alaska, I saw an awful lot of ragged looking block heater electric cords wrapped around radiator grills or flung in the back of pickups. Small villages and outside of city limits were pretty lax on electrical inspection too. I don't remember reading about fires from these cords which received much harsher treatment than Leaf charging cords.
Block heaters draw in the ballpark of 500-1000 watts, so not much different from standard L1. With the described mechanism for cutting off charge flow if voltage drops below 108 volts - one is looking at about 12 Amps x 20 volts = 240 watts -- about the heat generation of four 60-watt light bulbs.
Is the described system much different than where the L1 EVSE plugs into the wall?
Many of the block heaters I've plugged in drew 1,500W. I was even tempted once to buy a 2,000W block heater. I even had a 1,500W block heater on my VW Golf diesel. This is one of the main reasons I went with a Leaf. A Leaf gets better "MPG" than my 60mpg Golf does. And it also uses not that much more than the same amount of electricity too.

I must admit I used some awfully thin extension cords for that 1,500W block heater. Of course when the temperatures are as low as -40* there's probably not much chance of it heating up to the point of doing anything. But still, that's a lame excuse. I also had terrible problems with the wire insulation cracking and falling off and then the bare wires shorting out at those temperatures.

I've been contemplating an emergency extension cord to hook up to the 120V EVSE to make it longer. But for here I'll need a cord rated for extreme cold, especially if I'm going to use the correct wire gauge.
 
LEAF draws 1440 watts. No one should use a L1 EVSE on even a 12G Extension Cord or anything other than a dedicated proper 120V outlet. Any attempt to imply this is remotely safe is reckless IMO and very irresponsible. There are so many more variables to consider in the real world and it's simply a bad practice to justify even indirectly.

This assumes the worst 12 gauge extension cord, with the alternative being the best 120 volt wall outlet. A genuinely good 12 gauge cord plugged into a non-worn outlet will barely get warm. So rather than tell people not to do things they will do anyway, I suggest you tell them, as I do, to make sure the cord and outlet are both high quality and in excellent shape.
 
LeftieBiker said:
LEAF draws 1440 watts. No one should use a L1 EVSE on even a 12G Extension Cord or anything other than a dedicated proper 120V outlet. Any attempt to imply this is remotely safe is reckless IMO and very irresponsible. There are so many more variables to consider in the real world and it's simply a bad practice to justify even indirectly.

This assumes the worst 12 gauge extension cord, with the alternative being the best 120 volt wall outlet. A genuinely good 12 gauge cord plugged into a non-worn outlet will barely get warm. So rather than tell people not to do things they will do anyway, I suggest you tell them, as I do, to make sure the cord and outlet are both high quality and in excellent shape.

Because most people don't know what a "good outlet" is nor a proper 12G cord. Many LEAF owners have have had complete melting of the ends of "good" new extension cords. Reckless is recommending long 14G, 18G and other cords of very long lengths. Many of the "good" extension cords sold on Amazon are junk and have poor terminations that fail and melt.
 
desiv said:
EVDRIVER said:
Many LEAF owners have have had complete melting of the ends of "good" new extension cords.
So, just wondering..
How many is "many" in this case?

Thanx,

desiv


I know of at least 20 plus first hand and this is the type of thing that many consumers don't report. 120V charging is much higher risk and using an extension increases that risk dramatically. Since this is continuous load use there is no point in taking a risk. At least get a 10G or heavier well built extension if you are going down this route. Best bet is a quality cord with properly welded ends no screw connections or cheap cords from China with high resistance poor terminations.
 
EVDRIVER said:
I know of at least 20 plus first hand and this is the type of thing that many consumers don't report.
Doesn't sound like too many to me, but different perspectives.. ;-)
Also, I'm a cynic..
Nothing personal, but in the I.T. field, it's not umcommon to have people report that they know of at least 20 users that are having the same problem as they are, only to find out that the number is actually much less...
Not saying that it's the same with you.. Just that I'm a bit biased in that way.. ;-)

After all, I've read that 87.4% of statistics are made up on the spot.. :D

Still, it is good for people to be aware of possible danger..
These things draw a lot of power.
I always tell people, imagine you are plugging in a standalone electric heater and leaving it on for hours..
Be safe!! ;-)

desiv
 
I've read (here) that the Nissan trickle charger has a thermal overload protection (to detect the outlet heating up), and using an extension cord thwarts that protection. Is that true?
 
jlv said:
I've read (here) that the Nissan trickle charger has a thermal overload protection (to detect the outlet heating up), and using an extension cord thwarts that protection. Is that true?


It will cause it to drop the amp level on the EVSE when it heats.
 
jlv said:
I've read (here) that the Nissan trickle charger has a thermal overload protection (to detect the outlet heating up), and using an extension cord thwarts that protection. Is that true?

The thermal sensor is inside the plug. If connected directly to an outlet, it will sense the outlet heating up. If connected to an extension cord, it will only sense if the end of the cord is heating up. I believe, somewhere in the manuals, Nissan says not to use an extension cord.
 
For anyone reading this who is considering using an extension cord, you can do a few simple things and make yourself much safer.

1) Start with a new extension cord with large gauge wire. Lower numbers mean larger wire. Definitely do NOT use 14 gauge wire. 12 gauge is better and 10 gauge is the best you'll find in a common extension cord.

2) After charging for ten minutes, test the setup. Run your hand over the plug, jack, and wire ends. Do you sense any hot spots? A slight sense of warmth is normal and expected (perhaps 5 degrees hotter than outside air) but if it feels 20 degrees hotter than outside air, don't continue.

3) Be gentle with your extension cord. It will wear out quickly if abused. Don't flex it too much. Don't coil it into too small of a circle. Treat the wire at the plug and jack carefully. This is the most frequent point of failure. People will bend the wire right at the plug and jack with a very tight radius and cause the multi-strand wire inside to break at the point where it is rigidly connected to the plug and jack.

There is something unique about 120V EV charging - it is used for very long periods of time at full current, unattended. If there is a weak point in an EV charging cable, that point can heat up over time, leading to a further increase in resistance, leading to more heat, leading to physical motion of the wire causing conductors to separate, leading to arcing and fire. The risk is real and the consequences are potential fire plus potential loss of life. Block heaters have some of the same issues, but the higher-power block heaters have thermostats so they don't run full current continuously.

Disclaimer: I am not an electrician. I am not a licensed engineer. This is just common sense advice, not a guarantee or professional opinion. If you have any doubts, follow the instructions in the manual and don't use an extension cord.

Bob
 
Bob said:
For anyone reading this who is considering using an extension cord, you can do a few simple things and make yourself much safer.

1) Start with a new extension cord with large gauge wire. Lower numbers mean larger wire. Definitely do NOT use 14 gauge wire. 12 gauge is better and 10 gauge is the best you'll find in a common extension cord.

2) After charging for ten minutes, test the setup. Run your hand over the plug, jack, and wire ends. Do you sense any hot spots? A slight sense of warmth is normal and expected (perhaps 5 degrees hotter than outside air) but if it feels 20 degrees hotter than outside air, don't continue.

3) Be gentle with your extension cord. It will wear out quickly if abused. Don't flex it too much. Don't coil it into too small of a circle. Treat the wire at the plug and jack carefully. This is the most frequent point of failure. People will bend the wire right at the plug and jack with a very tight radius and cause the multi-strand wire inside to break at the point where it is rigidly connected to the plug and jack.

There is something unique about 120V EV charging - it is used for very long periods of time at full current, unattended. If there is a weak point in an EV charging cable, that point can heat up over time, leading to a further increase in resistance, leading to more heat, leading to physical motion of the wire causing conductors to separate, leading to arcing and fire. The risk is real and the consequences are potential fire plus potential loss of life. Block heaters have some of the same issues, but the higher-power block heaters have thermostats so they don't run full current continuously.

Disclaimer: I am not an electrician. I am not a licensed engineer. This is just common sense advice, not a guarantee or professional opinion. If you have any doubts, follow the instructions in the manual and don't use an extension cord.

Bob

All good advice. I'm not a licensed engineer, just a EE by degree, and the heavier a wire gage the better! Charging electric cars is a "high power" application, that's why I'm getting a 240VAC line run for it. And until then I'm using a 150FT early 1980's Craftsman 3 prong extension cord that I also use to mow, trim and leaf blow (all corded electric!) I can't remember it;s wire gage but I think it's 14 gage. Works wonderfully! Back when Craftsman was the GOOD STUFF! :)

John Kuthe...
 
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