Supercharger - Burlington, WA - 9400 Old Hwy 99 N. (under construction Nov 2023, 16 V4 stalls)

[Metalhead47]

Interesting read, thanks!

 

[Mrbrock]

Wires don't get hotter (higher temperature) with increased length, they get hotter with increased current. You're probably thinking of those warnings we get with appliances or tools, that have the wire gauge recommendation charts for extension cords. Household power is usually supplied at a fixed voltage to a more-or-less fixed load, and that's not the case for vehicle charging.

Wire has a resistance-per-foot factor, which is lower for larger wires and higher for smaller. If you start out with 350v at a source, 10' down the wire maybe you'd only see 348V; 20' down maybe 345V, and so on. The wire's resistance is converting power into heat. We don't want heat in the wire, we want the power at our load at the end of the wire, so we use a larger wire that has less resistance, so more power ends up at the load and less power gets turned into heat.

In the case of the Tesla car, both the supply voltage and the load is variable. If the car decides to ask for, say, 125 amperes maximum -- and the car does actually do that, that's the way DCFC works -- and if the Supercharger is capable at that moment of doing that -- the SCs have variable capability, based on a whole list of factors -- then the SC will set its output voltage to the battery pack voltage, the contactors in the car and in the SC close, and . . . nothing happens immediately. The voltage on both sides of the cable are the same, no flow. This is done deliberately, to lessen the wear on the contactors.

The SC then raises its output voltage on a ramp, while monitoring the current. It keeps pushing the delivery voltage higher until the agreed-upon maximum current is achieved.

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The SC "knows" the current-carrying capability of the cable, via installation configuration parameters. It therefore "knows" the maximum current capability it should deliver, and it won't push delivery voltage higher than what the measured maximum amperage is at any given moment. That changes, as the car's battery pack resistance changes: the pack's resistance goes up as it becomes more charged, so the SC has to push delivery voltage higher to achieve that maximum amperage.

What happens when you add an extension cord to the chain? More resistance. The car is communicating with the SC constantly, several messages per second, in effect telling the SC, "keep going, everything looks good here", or "time to slow down, the pack is almost full", and like that. But neither the car nor the SC knows about the extension cord, and neither cares about it.

If the extension cord is of equal wire gauge (is as large as) the SC's own charge cable, the effect is a little more voltage drop across the extension cord, and nothing else. Nothing gets hotter -- as long as the heat dissipation capability of the extension cable is the same as the SC's cable -- more on that below.

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The car and SC are communicating constantly. I don't know Tesla's protocol, but other DCFC protocols (CCS, CHAdeMO) will sometimes compare notes, eg the charger may say, "I'm sending 350v" and the car may reply "I'm receiving 345v", and if there's enough discrepancy, the charging session can be aborted due to a large enough mismatch of values. Various implementations of the "standards" means that, in the non-Telsa world, it can be possible for a mis-match of a certain magnitude of sent/received voltage to trigger a charge session abort on one manufacturer's charger, but not another. This means that in theory it would be possible in the non-Tesla world for a DCFC extension cable to work OK on one charger but not another. (I am working on a hobbiest level in the CCS world right now, and we run into this a lot: "I love standards, so many to choose from!")

Fortunately, this extension cable supplier only has to deal with testing a single manufacturer's charger: Tesla! So, if it works on one SC, it should work on them all.

I'd be curious to know the technical details of how this extension cable tells the SC to limit the max current to the extension cable's max (it's not a liquid-cooled cable, so I'd guess it can't deliver what a SC's liquid-cooled cable could, without overheating), but in the end I don't need that info, as long as it does it. But it's not the length of the cable that's a concern, as long as it can dissipate heat as well as the SC's cable can.

We have established that V3 is liquid cooled so if it works on V2, it will not work on v3. There is no cooling passed through the connector so no extension cord could be cooled unless it has its own liquid tubes, cooling liquid, cooling compressor and pump all designed to run off 350v DC.

The extension cable doesn’t talk to the car or the charger. If the cable gets too hot, the only way it will be reported is if the charge port on the car senses the heat or the connector on the SC cable senses it. This is dangerous. Like the cooling, there are no pass througha for sensor communication in the connector because they are not needed. The manufacturer needs to state it can only be used with V2 and have very detailed and specific instructions to help users identify this. Or the wire needs to be spec’ed for 250kw at ambient temps so would need to be significantly thicker than V2 cable.

Better yet, they need to stop selling this. As we have established, Magic Dock CCS is only available on V3 so this cord would not work with CCS cars needing an extension without being redesigned.

 

[asavage]

You'd want to go in eyes-wide-open, sure. I am not a Tesla owner -- we sold our Model 3 -- so I have no interest in this extension cord, but at the price they're asking for it -- $550 -- it's possible that it's not just two connectors and some heavy wire. The cable might have either a pass-through (man-in-the-middle) signal snooper that can spoof the data the SC reads for the vehicle's capability, so the SC never supplies "too much" current for the extension cable. That's an approach I'd consider, if I was building a cable like that.

Or, it may incorporate it's own shunt to measure either temperature at one of the connectors or real measured current, and do something similar to above. The Tesla's charge port does monitor temperature already, and I assume it can tell the SC to slow down, if the charge ports gets too hot. This cable might rely on that mechanism all by itself.

I don't make the thing, and I'm not interested in buying one, but I wouldn't dismiss using an extension cable like this out-of-hand without more info. It could solve a real problem (if it works).

I have a 20' J1772 extension cable that I've been carrying around for five years, and I've really needed it only twice, but when you need it, it's sure nice to have

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I just ran across a different supplier of this kind of Tesla extension cable, and they also state it's OK for use up to 350kw.

Tesla Supercharger Extension Cord 14ft • AC and DC Charging Public Network Compatible

New Tesla Extender, compatible with Level 1, 2 and Level 3 chargers. Extremely Durable. 2 Year Warranty. All Tesla Models. All Weather Extension Cable Is Here.

evadept.com

Extension Cable for Supercharger​

This adapter is 100% DC compatible and will work with the Tesla Supercharger Network up to 350 kW.

 

[Mrbrock]

You'd want to go in eyes-wide-open, sure. I am not a Tesla owner -- we sold our Model 3 -- so I have no interest in this extension cord, but at the price they're asking for it -- $550 -- it's possible that it's not just two connectors and some heavy wire. The cable might have either a pass-through (man-in-the-middle) signal snooper that can spoof the data the SC reads for the vehicle's capability, so the SC never supplies "too much" current for the extension cable. That's an approach I'd consider, if I was building a cable like that.

Or, it may incorporate it's own shunt to measure either temperature at one of the connectors or real measured current, and do something similar to above. The Tesla's charge port does monitor temperature already, and I assume it can tell the SC to slow down, if the charge ports gets too hot. This cable might rely on that mechanism all by itself.

I don't make the thing, and I'm not interested in buying one, but I wouldn't dismiss using an extension cable like this out-of-hand without more info. It could solve a real problem (if it works).

I have a 20' J1772 extension cable that I've been carrying around for five years, and I've really needed it only twice, but when you need it, it's sure nice to have

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I just ran across a different supplier of this kind of Tesla extension cable, and they also state it's OK for use up to 350kw.

Tesla Supercharger Extension Cord 14ft • AC and DC Charging Public Network Compatible

New Tesla Extender, compatible with Level 1, 2 and Level 3 chargers. Extremely Durable. 2 Year Warranty. All Tesla Models. All Weather Extension Cable Is Here.

evadept.com

That page only mentions Destination, HPWC and UMC in the title. No DCFC in the title. It does mention it in the description but that cable looks no thicker than the Gen 2 HPWC cable that is 100A rated (80A actual) which is minimum 3ga copper thhn. That’s 19kw. Increasing V from 240AC to 350DC gets you to 28kw. Thats 1/5th what is needed for V2 SC and 1/9th for V3. V2 requires 535A rated wire for 150kw. That’s 1000kcmil cable, 1.75 inch in diameter for 2 conductor, unless there are other factors that allow Tesla to use smaller wire. But still nowhere close to to HPWC wire. UL listed? Tested at full charge from 5% to 90%? Or just plugged in at 85% (40kw)?

Also, keep this in mind. The SC has sensors to shut down so they will remain safe. Tesla says to not use extension cords for any charging so if you do, it’s your fault. If this cable causes your car to catch fire, Tesla doesn’t care.

 

[Mrbrock]

Marco has located the site plans:

https://twitter.com/x/status/1623751089337008128

Something random caught my eye, the posts in the drawings are V4 (V3 is just an oval). There are usually alternate posts on the equipment page but the overall site drawings having been using V3.

Plan for Vacaville, CA submitted 9/22.

 

[Big Earl]

Something random caught my eye, the posts in the drawings are V4 (V3 is just an oval). There are usually alternate posts on the equipment page but the overall site drawings having been using V3.

View attachment 926463

Plan for Vacaville, CA submitted 9/22.
View attachment 926467

Very interesting! I cruise by every week or two - so far nothing to report.

 

[Mrbrock]

Very interesting! I cruise by every week or two - so far nothing to report.

From permits, it looks like the hotel at the original site is being remodeled (to the tune of $2mil, original hotel was valued at $3mil in 2005). Are any of the current spots impacted?

 

[Big Earl]

From permits, it looks like the hotel at the original site is being remodeled (to the tune of $2mil, original hotel was valued at $3mil in 2005). Are any of the current spots impacted?

Hotel construction is not impacting the existing Supercharger. The hotel also appears to be open for business during renovations - at least for now.

 

[Mrbrock]

Hotel construction is not impacting the existing Supercharger. The hotel also appears to be open for business during renovations - at least for now.

Any signs of construction?

 

[Big Earl]

Nothing as of last week - not even paint markings. I'll stop by again the next time I'm over there.

 

[Mrbrock]

Nothing as of last week - not even paint markings. I'll stop by again the next time I'm over there.

Yeah, nothing on dig tickets but you never know if it would be tied into the hotel and not show up as a Tesla search or black stone. Doubtful it wouldn’t show up under one of those but you never know.

 

[Big Earl]

Hotel renovations are complete. No news on the Supercharger front.

 

[Mrbrock]

Probably have to put this in the queue at Blackstone.

 

[Mrbrock]

Hotel renovations are complete. No news on the Supercharger front.

Looks like Blackstone gets a pass on this one. Dig ticket doesn’t say Tesla but given it points to the exact area drawn in the plans, this has to be for superchargers.

 

[Big Earl]

Looks like Blackstone gets a pass on this one. Dig ticket doesn’t say Tesla but given it points to the exact area drawn in the plans, this has to be for superchargers.
View attachment 990274

Very interesting. I’ll head over tomorrow to get some pictures.

 

[Mrbrock]

Very interesting. I’ll head over tomorrow to get some pictures.

Then there’s this…A little clearer.

 

[Mrbrock]

Very interesting. I’ll head over tomorrow to get some pictures.

Also, this company did the groundwork at the new Cle Elum station so it is not a new company to Tesla or Polarity River.

https://www.searchandstatus.com/warecApp/ticketSearchAndStatusView.jsp?enc=bStOQqUnHSyuAia%2FH6H0sJhXHQwgohb%2FtMz0hBgtfaoKHqwIReHImh%2FNJGxlfyVS

 

[Big Earl]

Burlington is turning into a major charging hub, with soon-to-be three Tesla Superchargers, one EA and several other DC fast chargers. Meanwhile, Bellingham still doesn't have a Supercharger.

 

[Big Earl]

Fencing and a telescoping material handler are on site. Markings have been made and it looks like they’re ready to start construction.

The stalls will go in the row of parking spaces that separate Bob’s from the espresso hut.

 

[kilpatds]

Burlington is turning into a major charging hub, with soon-to-be three Tesla Superchargers, one EA and several other DC fast chargers. Meanwhile, Bellingham still doesn't have a Supercharger.

I've noticed that my car really really LOVES the old burlington location, despite the new one usually making more sense.... an expansion to the old site (like this appears to be) would at least keep me from fighting with the nav as much.