Tesla engineer warns against using extension cords at Superchargers

[Peter P]

Per Wes Morrill of Tesla:

"Would recommend AGAINST using an extension cord on a supercharger (or any DC charging station with a liquid cooled cable). Have seen multiple instances of the cable overheated and shorting DC +/-

There's a temperature measurement in the handle and the supercharger derates based on that temperature. With the extension cable that safety goes away. On top of adding an additional junction which generates heat making matters worse."

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[Kit2874]

No problem Chevy and Ford will just take up to 2 to 3 spots... I was in louisiana at a tesla charging...

Six of the eight charges were available... And both ones that weren't available Where the outside ones instead of the inside ones... And one of the tesla drivers in a model Y was using the one That's for cyber trucks So he didn't have to back in...

I Try to be courteous... But when you have tesla drivers do that... And then One of the tesla Drivers had the audacity to tell me.I was taking up two spots...

I just Told him to call the tesla police

 

[FloridaMan655321]

I'm not sure I would want to do 350kW over an extension cable, but I think I'd be ok with 100-150kW. Also, we (and I assume Chevy/Rivian) only need about 1-2ft, so you can really over engineer it without it not costing a stupid amount.

 

[Monkey]

That NACS adapter gets pretty hot and that’s with the truck taking in less than 180kW at peak and most of the charge curve being a good bit lower. Adding the extra resistance and bulk of an extension cable just seems like a bad idea. Tesla just needs longer cables on their charger, which the newer V4 pedestals do have…. But it seems even with that, we still have to straddle spaces for the cable to work for the Lightning.

I Try to be courteous... But when you have tesla drivers do that... And then One of the tesla Drivers had the audacity to tell me.I was taking up two spots...

I just Told him to call the tesla police

Show them Tesla’s own guidance on how to straddle spaces to charge your non-Tesla EV. I showed a lady that the first time I tested my NACS adapter. First she was going to tell me that I can’t charge there, Tesla only, it won’t work…. Then I explained to her that Tesla opened up to Ford, Rivian and soon others and showed her it was charging. Showed her Tesla’s info on how to straddle spaces. She commented on how Ford was stupid for not putting the charge port in the right spot, but was otherwise receptive.

 

[djstough]

...She commented on how Ford was stupid for not putting the charge port in the right spot, but was otherwise receptive.

Much like I've complained for 40 years that some manufacturers put gas fills on the right side of the car, or "gasp", on the front fender!

 

[The Weatherman]

Per Wes Morrill of Tesla:

"Would recommend AGAINST using an extension cord on a supercharger (or any DC charging station with a liquid cooled cable). Have seen multiple instances of the cable overheated and shorting DC +/-

There's a temperature measurement in the handle and the supercharger derates based on that temperature. With the extension cable that safety goes away. On top of adding an additional junction which generates heat making matters worse."

I’ld be wary of that cable. It’s showing as UL Certified and as I understand it, there are no finalized specifications for completing UL testing and listing.

 

[Maquis]

I’ld be wary of that cable. It’s showing as UL Certified and as I understand it, there are no finalized specifications for completing UL testing and listing.

“UL Certified” is meaningless. It must be listed to a standard and be given a listing number.

 

[Kit2874]

Much like I've complained for 40 years that some manufacturers put gas fills on the right side of the car, or "gasp", on the front fender!

I miss the days when you just folded down Your license plate like in my 74 firebird

 

[Revenge]

So correct me if I have any of this info wrong. To my understanding V3 Superchargers are liquid cooled but V2 are not. While we can now charge at V3 stations the rate our trucks can accept is pretty much V2 speed. So if we can only charge at V2 speeds and those cables don't need to be liquid cooled why would an extension cable that in NOT liquid cooled be an issue.

 

[jetfixr1]

So correct me if I have any of this info wrong. To my understanding V3 Superchargers are liquid cooled but V2 are not. While we can now charge at V3 stations the rate our trucks can accept is pretty much V2 speed. So if we can only charge at V2 speeds and those cables don't need to be liquid cooled why would an extension cable that in NOT liquid cooled be an issue.

The truck still accepts the full 425 amps the V3 is rated at. 425A x nominal pack voltage on the Lightning = 160 KW charge speed (give or take). Compare that to an 800V architecture vehicle, the amperage is the same at a V3, but the 800V is what allows it to accept a higher charge. One can only assume Tesla made the V3's liquid cooled for uptime and reliability.

 

[BeeKind]

I'm not sure I would want to do 350kW over an extension cable, but I think I'd be ok with 100-150kW. Also, we (and I assume Chevy/Rivian) only need about 1-2ft, so you can really over engineer it without it not costing a stupid amount.

What exactly are you basing this on? What's the gauge of you wire? What is it made out of? Is it cooled? Cannot overstate you can't just throw around 150kW and extension cords lol.

 

[FloridaMan655321]

I miss the days when you just folded down Your license plate like in my 74 firebird

I was thinking about this the other day. How nice it would have been if the charge port was back there. I'm sure it's not as good for when charging stations are designed more like regular gas stations.

 

[FloridaMan655321]

What exactly are you basing this on? What's the gauge of you wire? What is it made out of? Is it cooled? Cannot overstate you can't just throw around 150kW and extension cords lol.

Oh I agree. I'm more thinking if they design it to be rated for 250+, we are only at 150, so *should* be safe. I'm not saying it's as good as the cables coming from the supercharger.

 

[Firn]

Oh I agree. I'm more thinking if they design it to be rated for 250+, we are only at 150, so *should* be safe. I'm not saying it's as good as the cables coming from the supercharger.

The thing here is that current is the limiting factor, not Kw. Current is what makes heat. On a 800v architecture it's actually using less current at 250kw then we use at 150kw

 

[RickKeen]

What exactly are you basing this on? What's the gauge of you wire? What is it made out of? Is it cooled? Cannot overstate you can't just throw around 150kW and extension cords lol.

Well understood to figure out what size wire you need for 500 amps with air cooling. Easy enough to buy the right wire. Check the charts you will see you need like 373 kcmil copper. Bulky and costly, but not impossible.

https://www.wireandcableyourway.com/373-diesel-locomotive-cable-2kv

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