Thoughts on the "World's First Tesla extension cord"?

[mswlogo]

Well yes, it probably will work just fine at 40A. And that appears to be its intended use.

But the point is that there is nothing stopping you from plugging it into a supercharger. And neither the car nor the supercharger will know about it. And the car will try to draw hundreds of amps through it. And it's going to fry. The only thing stopping that from happening is a smart user who knows not to connect it to a supercharger. That's not good enough.

I doubt there is much application for using it for a super charger. I suspect that there is some communication that goes through the supercharger cable that would not pass through the extension. And like someone mentioned it might sense something is very wrong with the huge voltage drop.

The real danger is using it in a wall connector. The cord on a wall connector is way beefier than that extension. Not sure if the wall connector would detect an issue.

Like others said I’d never buy anything like that. I’m sure it’s Chinese crap that has no regulation or certification. It probably would work at 32 A and no more. Still wouldn’t touch it.

 

[mongo]

I doubt there is much application for using it for a super charger. I suspect that there is some communication that goes through the supercharger cable that would not pass through the extension. And like someone mentioned it might sense something is very wrong with the huge voltage drop.

The real danger is using it in a wall connector. The cord on a wall connector is way beefier than that extension. Not sure if the wall connector would detect an issue.

Like others said I’d never buy anything like that. I’m sure it’s Chinese crap that has no regulation or certification. It probably would work at 32 A and no more. Still wouldn’t touch it.

Any communication on the supercharger cable would be carried through the extension via the non-high current signal pins. Similar to how the car communicates with the HPWC.

 

[Phlier]

Any communication on the supercharger cable would be carried through the extension via the non-high current signal pins. Similar to how the car communicates with the HPWC.

Yup, and from the look of it, that "extension cord" looks to have those wires in it.

 

[TT97]

Like others said I’d never buy anything like that. I’m sure it’s Chinese crap that has no regulation or certification. It probably would work at 32 A and no more. Still wouldn’t touch it.

TeslaTap sells similar extension cords (since before the "world's FIRST Tesla charger extension cable.") Theirs cables come from either the Tesla UMC or the HPWC rated for either 32 Amps or 80 Amps. Technically, that makes them "Chinese crap" as well as that is where Tesla gets their connectors.

UMC-J1772 Store

 

[dsgerbc]

I can't imagine there will be a market for this thing.

Sure there is. To block an ICEr at a charger and still charge with a cable running over their roof.

 

[KenC]

 

[davewill]

QuickChargePower is pretty good at this stuff. If it's possible to engineer it to refuse to work on a Supercharger, they will. I find this whole thread one big FUD fest of ridiculous speculation. They've been selling J1772 versions of this for a long time, and this just isn't that much different. If you don't like it, don't buy one.

 

[darth_vad3r]

They've been selling J1772 versions of this for a long time, and this just isn't that much different.

It’s not THAT much different ... but I don’t know of any 150 or 250 kW DCFC stations that use J1772 that could melt or fry a J1772 extension cable.

This comes down to the basic reason different voltage and amperage circuits use physically different shaped NEMA connectors ... to protect people from stupid.

 

[SomeJoe7777]

I doubt there is much application for using it for a super charger. I suspect that there is some communication that goes through the supercharger cable that would not pass through the extension. And like someone mentioned it might sense something is very wrong with the huge voltage drop.

The real danger is using it in a wall connector. The cord on a wall connector is way beefier than that extension. Not sure if the wall connector would detect an issue.

Like others said I’d never buy anything like that. I’m sure it’s Chinese crap that has no regulation or certification. It probably would work at 32 A and no more. Still wouldn’t touch it.

I agree there's little application for using it at a supercharger, but I can think of a few. Model X towing a trailer, for example. You can't pull into the supercharger stall without disconnecting the trailer, so I can easily see someone pulling up to the supercharger stations and using the extension cord because they don't want to disconnect the trailer.

Making it so that J1772 protocol would go through the extension but not SuperCharger protocol would involve a highly sophisticated microprocessor-controlled circuit that would have to decode the protocol. I virtually guarantee that is not implemented in this cable as it would drastically raise the cost.

The voltage drop on the cable might indicate enough to the car that the charging session should be stopped, but there's no guarantee of that. In fact, the car might not notice. As the voltage drop across the cable increases with the increasing current, the voltage at the car drops. The car would actually tell the supercharger to increase the voltage further so that the desired charge rate would be maintained. Only if the supercharger and the car communicated and told each other what the voltage was on their own end would the large voltage drop be recognized and I'm not sure if the supercharger protocol includes such cross-checks.

You're right that using it on a wall connector is just as or more dangerous. J1772 protocol is used, so even a microprocessor-controlled circuit couldn't stop it unless it was watching the commanded current value and shut it down if it's too much. Even then, such a thing could never get certified by UL or NEMA since active protection is required for the overcurrent condition.

 

[davewill]

...
People like you are why half the things in the world are as messed up as they are. Because you refuse to listen to the people who know more than you do, and you're arrogant enough to think that you know better.

Personal attack? Welcome to my ignore list.

P.S. Try reading more carefully. My post is none of the things you claim it is... but don't bother telling me about it.

 

[mongo]

The car would actually tell the supercharger to increase the voltage further so that the desired charge rate would be maintained. Only if the supercharger and the car communicated and told each other what the voltage was on their own end would the large voltage drop be recognized and I'm not sure if the supercharger protocol includes such cross-checks.

Control is current based with the supercharger having a max output voltage limit.

 

[SomeJoe7777]

Personal attack? Welcome to my ignore list.

P.S. Try reading more carefully. My post is none of the things you claim it is... but don't bother telling me about it.

You started the personal attack. You specifically labeled posts in this thread as "FUD", many of which are by me. I hold a Bachelor of Science in Electrical Engineering and I've been doing electrical calculations for almost 35 years. Flippantly dismissing what I (and several others) have said in this thread as "FUD" amounts to a personal attack, to which I will respond in kind.

Ignore me if you want. But you can't ignore physics. Plug this cable into your car and supercharge with it. See what you can ignore then.

 

[SomeJoe7777]

Control is current based with the supercharger having a max output voltage limit.

True. But I think that's part of why the car might not be able to tell that anything would be wrong. The car asks the supercharger for X amps. The supercharger will just keep raising voltage until it gets to that current. Unless the supercharger informs the car about the source voltage, where the car can compare it with the battery terminal voltage, the car won't know that a large voltage drop across the cable is occurring.

 

[darth_vad3r]

The voltage drop on the cable might indicate enough to the car that the charging session should be stopped, but there's no guarantee of that. In fact, the car might not notice. As the voltage drop across the cable increases with the increasing current, the voltage at the car drops. The car would actually tell the supercharger to increase the voltage further so that the desired charge rate would be maintained. Only if the supercharger and the car communicated and told each other what the voltage was on their own end would the large voltage drop be recognized and I'm not sure if the supercharger protocol includes such cross-checks.
.

You mad bro. Tesla’s totally got you covered ... they shut off the current, see ...

In 2016, a Tesla Model S in Norway caught fire within minutes of being plugged into a Supercharger, and the most likely cause was determined to be a bad connection inside the car. Interestingly, the Supercharger did eventually detect a problem and shut off, but whether that problem was an inability to deliver the expected amount of current, or from monitoring the voltage drop along the entire charging circuit, is unknown.
​

So, all is good. After your car bursts into flames you won’t get hit with idle fees cuz it stops charging. Or wait, no ... damn, that’s gonna cost you in idle fees actually, as soon as the session stops you go idle, and since the connector is in flames and melting you can’t disconnect and return it to the station so actually you might get hit with a lot of idles fees. I think they might waive the idle fees for your first fire though.

Source: Charged EVs | The technical reasons Tesla would limit supercharging speed, and other practical charging considerations

 

[brkaus]

The cord may be great, but when using it, the UMC can't monitor the wall outlet temperature.

The gen1 UMC never monitored the outlet temp.

definitely a good feature of gen2.

 

[fourier]

Unless I'm mistaken, I don't think the Supercharger would cause a fire. Superchargers don't instantly feed maximum power, they ramp up to it. And it likely does this on purpose, analyzing the resistance drop as it does so, and killing power if it goes out of spec. So in theory, it should shut off long before the cable goes up in flames.

That said, still not regulated, I ain't hooking nothin' up to my car that isn't UL rated, that's for damn sure.

 

[FlatSix911]

What is your evidence or engineering analysis that this would be the case?
You mean just like the speculation you gave in the sentence quoted above? That it's possible to engineer it to refuse to work on a supercharger? That is your pure speculation. I know exactly what would be required to make it refuse to work on a supercharger, and I'm going to say that there is a very good chance that this cable doesn't have it.

If you genuinely believe that a J1772 extension cable and the Tesla connector extension cable that is being discussed here "aren't that much different" then you have a fundamental misunderstanding of what the issue is. It means you aren't qualified to even offer an opinion on the subject. People like you are why half the things in the world are as messed up as they are. Because you refuse to listen to the people who know more than you do, and you're arrogant enough to think that you know better.

Joe, time to dial down the personal attacks here... or you will be taking a forced TMC vacation.

 

[brkaus]

Come on. There are lots of Tesla adapters that we’re made out of necessity in the early days. These are not safe unless the settings are all correct.

this cord will have it’s limits known. As long as it’s used within those limits it will be fine.

They still sell blenders. If you stick your hand in them bad things will happen...

 

[qdeathstar]

Ah yes, being able to tell the current carrying abilities of a product by pre production photos.

Hi. Do you know what sooj cord is or what it looks like? Do you have a HPWC? Do you see how thick that cable is for 8awg wire? It’s almost as thick as the handle of the charger... an extension cord would have to be a higher gauge like 4awg.... so it would need to be thick. The picture shows a thin cable that can’t be more than 10 awg. That’s dangerous. if they used proper cable my feeling is that they would advertise that, but they are mum on the details,

 

[Watts_Up]

You should do some researches before calling it the "World's First Tesla extension cord"

In particular there is a company called TeslaTap providing several Tesla Adapters and Tesla Extension Cords