Charging Speed. Not disappointed.

[electrictaco]

So I'll say it again. EA and Tesla are both members of CHaRin and so adhere, to at least to some extent, to the CHaRin standards the applicable one here being HPC350. The HPC350 envelope is bounded by a maximum voltage of 920V and a maximum current of 500A. A compliant station must be able to provide any voltage/current combination between those limits that results in less than or equal to 350kW (i.e. there is 'bite' missing from the 920V x 500 A corner of the box). Moving up the 500A boundary line 350 kW is reached at 700 V. If the vehicle, assuming it has a 400V battery pack, asks the charger for 700V if that battery pack has an impedance of (700 - 400)/500 = 0.6Ω, then the charger will push 500 A through it and it will charge at 350 kW, less, of course, the 150 kW dissipated in the battery impedance. So it isn't likely that the actual vehicle load line is going to slope at 0.6Ω or that the vehicle will ask for 700V if it does. Understanding what is really happening depends on knowing that load line which of course we don't.

Don't forget that Rivian filed a patent in which the 400V pack would be split into two halves connected in parallel for driving and series for charging. This results in battery load lines which begin (at the low current end of the envelope) at around 800V and which have double the slope of parrallel configuration load lines meaning that their high current ends easily apprach the 350 kW boundary in the upper right hand corner of the diagram;

No 400V vehicle would ask a charger for 700V, that would throw an over-voltage fault and stop charging. The "150 kW impedence" that you're referring to is going to light your car on fire.

Assuming that Rivian has gone to production with a voltage switching technology only seen in a patent a few years ago is not a good assumption.

Tesla is in CHaRin, but only for the Megawatt Charging Standard and they don't abide by the CHaRin CCS HPC350 protocol on their Superchargers. Here's an image of the Tesla label with a 631A output current, clearly in violation of HPC350: https://pbs.twimg.com/media/EQWlgz8W4AAOnDr?format=jpg&name=large

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[ajdelange]

No 400V vehicle would ask a charger for 700V, that would throw an over-voltage fault and stop charging. The "150 kW impedence" that you're referring to is going to light your car on fire.

I'd rather hoped that was clear. I'll also point out that my X occasionally absorbs 150 kW (in its motors) and nothing lights on fire. What I was really hoping was that you would understand the principle well enough to be able to work your own numbers in which at this point must be hypothetical. I'll reiterate that no one knows Rivian's load line other than Rivian and it is thus impossible to determine where along it Rivian is operating or how far along it they actually go in the current software iteration.

Just spotted something else: If the car asked for 700V an HPC350 charger would give it 700V. It is required to. Of course the car would never ask for 700V.

 

[Voronbrg]

I've been to EA 350 kw station that was pretty new. Never seen that high, most I've seen was 157ish.

 

[zipzag]

I've decided that the max pack is delayed because it will be 800v split. All of us who waited for max pack will be smug.

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