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Discussion Starter · #1 ·
With Porsche and others announcing the deployment of a 350 kW DCFC network, and Tesla currently offering up to 150 kW on their network, I wondered: What is the upper limit of the Tesla adapter?

I ask because I remember reading an article interviewing Tesla CTO, JB Straubel, where he mentions the need for a new charging standard in order to support 10 minute or faster Supercharging. In the interview, he stated that the current standard wasn't up to the task, but he never stated what the actual upper limit is.

Is it possible that the SAE DCFC standard is every bit as capable as the "elegant" Tesla charge plug?

Is it possible that the SAE DCFC standard can actually support a higher charge rate than the Tesla proprietary standard?
 

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Amps are the same, going through the copper. The voltage jumps to 800V, though. Tesla tested liquid cooled charging cords and handles specifically for this, and the flexibility for the autonomous charging "snake". If you're asking if the TSL02 connector that is ubiquitous among NA and JP Teslas, Superchargers, Destination Chargers, etc. the answer is yes.

Since 2017 is the year of 350kW charging, expect to hear about a " 400/800V Combo" battery in Spring.
 

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Discussion Starter · #3 ·
Amps are the same, going through the copper. The voltage jumps to 800V, though. Tesla tested liquid cooled charging cords and handles specifically for this, and the flexibility for the autonomous charging "snake". If you're asking if the TSL02 connector that is ubiquitous among NA and JP Teslas, Superchargers, Destination Chargers, etc. the answer is yes.

Since 2017 is the year of 350kW charging, expect to hear about a " 400/800V Combo" battery in Spring.
I'm not sure what you mean by this. I know TSL02 is the standard adapter for Tesla, but I'm asking what the upper limit is. Currently, they aren't providing anything more than 135 kW charging.
 

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The latest superchargers are 135 kW (330 amps @ ~400V) Apparently the liquid cooled cables weren't as dependable: https://electrek.co/2016/07/21/tesl...iment-in-mountain-view-but-the-tech-lives-on/

I believe that it might be possible to achieve double rates by switching the pack wiring for charging. Those new DeWalt FlexVolt batteries work this way. They have 15 2Ah lithium cells. For 60V applications the 15 cells are connected in series (2Ah) For 20V applications the cells are connected as 3 parallel groups of 5 (6Ah)

800V charger wiring is certainly doable, but 1200V would be less viable since 1000V wire is highest commonly available. 270kW charging on a Tesla would be very appealing, but such a system would require substantial modification to the battery pack to allow the series/parallel switching.
 

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Discussion Starter · #5 ·
That makes me wonder how Porsche and others plan to use the DCFC standard to pump 350 kW. Tesla seems to push much higher amps, but the voltages seem to be the same. Maybe [email protected]?

So the current cap on Tesla is their cars' battery packs? I know thermal management issues are one of the concerns for pumping up to 270 kW and beyond, but that was also on the charger end.

Oh, well. I guess we'll just have to wait and see how these companies start to push these rates out.
 

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Going much higher than 150kW without substantially increasing pack voltages would require larger pins, thicker cables, etc. to handle the higher amps. I don't think there's anything about the CCS standard/connector that has a leg up on the Tesla connector in that regard.

Pretty sure that's the case.

My understanding was always that talk about ultra-fast, extra-high voltage charging (350kW) was predicated on a future battery pack design with higher voltages, rather than a strategy based on a switching mechanism that would only temporarily increase the pack voltage during charging via parallel/series switching. But I could be wrong on that.

This site has a decent explanation of the basics behind fast charging. (Volts, amps, etc.)
https://medium.com/@Fastned/the-exciting-future-of-fast-charging-f4cf06b9976d#.mezdbfk64
 

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Well higher pack voltages would allow for lighter cabling and motors (the inverter semiconductors could also be lighter but their weight is negligible to that of the heatsink)

I think it's interesting how just about every manufacturer uses some variation of 96 cells in series, which gives you a ~375V nominal pack.
 

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Going much higher than 150kW without substantially increasing pack voltages would require larger pins, thicker cables, etc. to handle the higher amps. I don't think there's anything about the CCS standard/connector that has a leg up on the Tesla connector in that regard.

Pretty sure that's the case.
One of the selling points of Tesla was that the charge cable and port are "small and sleek" compared to J1772 DCFC standard. I tried to look up the pin sizes on various types of DCFC, and couldn't find them. Heck, I didn't realize the Tesla "Standard" is not standard! They use a different plug in Europe than they do in North America.

Keith
 

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Discussion Starter · #10 ·
This is the IEC 62196-3 standard which is yet to be ratified.
Up to 1000VDC and 400A. I would pull up the IEC document, but I don't want to spend $207USD just to look at a PDF.
So the new standard will be up to 400 kW. That's pretty sweet. I think that Tesla has proved that even 100 kW charging is enough to make a vehicle a no-compromise car for many, and I personally feel that 200-300 kW would be more than fast enough to win a majority of people over.
 
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