Is preconditioning before DCFC really worth it?

[smashweights]

Ok so I gave it a fair shake today. We drove about 90 miles to the airport. The last 20 miles I preconditioned the battery to use a DCFC near the air port to top up before we left it sitting for a week at the long term lot.

Ambient temp 55, battery was about 75 the whole drive because of home charging and driving, motors we're about 150 when I started. Battery went from 75 to 87 in about 2 minutes without any change in the efficiency graph. Motors didn't get hot like they did before. So you all are definitely correct. Rivian was probably try to work extra hard to heat the battery on the short drive before with motors that hadn't even warmed up.

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[tivoboy]

Pre-conditioning or not, what is the BEST charging rate that these Rivian can achieve with a NACS plug at a Tesla Supercharger? Is it 200, 210 250? At the peak of the curve?

 

[Mellowyellow]

215-220 but doesn’t hold it for long

 

[smashweights]

Pre-conditioning or not, what is the BEST charging rate that these Rivian can achieve with a NACS plug at a Tesla Supercharger? Is it 200, 210 250? At the peak of the curve?

I briefly hit 211kW while preconditioned to 87 degrees with about 55% SOC at a supercharger with an adapter.

 

[tivoboy]

I briefly hit 211kW while preconditioned to 87 degrees with about 55% SOC at a supercharger with an adapter.

I would think/hope that a true NACS connector would be able to provide even slighthy higher peak rates, even just another 5%, and possibly overall avg charging.. that curve though of your session looks pretty good though, not a huge drop off. I’m hoping that the BMS and charging system in the R2 might be slightly most optimized in the end.. we’ll see.

 

[VandalSibs]

I would think/hope that a true NACS connector would be able to provide even slighthy higher peak rates, even just another 5%, and possibly overall avg charging.. that curve though of your session looks pretty good though, not a huge drop off. I’m hoping that the BMS and charging system in the R2 might be slightly most optimized in the end.. we’ll see.

Whether the connector is NACS or CCS1 has no major bearing on the charge curve and rate of charge - the BMS asks the charger to provide a particular amount of power at any given time, and if the station can provide it, it does.

The only physical difference between NACS and CCS1 is that NACS shares it's primary AC & DC power pins, while CCS1 separates them. The amount of power that is being requested by the vehicle hasn't changed.

 

[tivoboy]

Whether the connector is NACS or CCS1 has no major bearing on the charge curve and rate of charge - the BMS asks the charger to provide a particular amount of power at any given time, and if the station can provide it, it does.

The only physical difference between NACS and CCS1 is that NACS shares it's primary AC & DC power pins, while CCS1 separates them. The amount of power that is being requested by the vehicle hasn't changed.

You don’t think having a CCS to NACS adaptor in use does anything to reduce the overall maximum throughput, negotiated or metallurgically possible vs. a straight single point of communication and connection?

 

[VandalSibs]

You don’t think having a CCS to NACS adaptor in use does anything to reduce the overall maximum throughput, negotiated or metallurgically possible vs. a straight single point of communication and connection?

I was considering port vs port, no adapter in consideration (comparing a 2025 vs 2026 R1). That being said, I don't think the extra inch or so is the hugest factor..... but I'm also not an electrical engineer, so maybe there is a larger effect.

That being said, nothing has changed on the battery & BMS situation between the two model years that I'm aware of, so the charge curve, thermals, etc. are not affected by an NACS port vs CCS1 port.

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