Battery voltage confirmed: 400V-450V

[DucRider]

I guess in reality that isn't too bad I just wonder what the charging curve will be, if it can sustain 200KW for at least 80% SOC or will it take 1.5 hours+ to to get to at least 80% SOC for long travel.

Average charge rate of as low as 160 kW would result in <30 minutes for a 20-80% charge on the large pack. WAG that charge will take about 25 minutes, adding a few more minutes if you run it down to 10%.

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[CommodoreAmiga]

The math is simple and has direct correlation. We know the vehicle is about 425-450W per mile, or 2.2-2.35 mile per KW.

Charging at 200KW for 20 minutes = 67KWH. 67KWH * 2.2mile/KWH = 147 miles, assuming no charging loses. There will be charging losses, so 140 miles in 20 minutes is equal to 200KW charging rate. Below 50% SoC (400V nominal) the rate will be slightly less than 200KW, and above 50% SoC it will be slightly more.

So yes, the web site makes two independent statements, but those statements are completely consistent with each other.

I disagree.

If the vehicle supports SUSTAINED charging at OVER 200kWh then the vehicle would have to support HIGHER charge rates.

Let’s break it down.

1. Rivian says OVER 200kWh. That alone confirms MORE than 200kWh.

2. RJ has previously mentioned 300kWh. Things are subject to change, of course, but consider that it WAS said.

3. Rivian says SUSTAINED. Vehicles don’t charge at their MAX rate for sustained periods of time. In order to sustain 200kWh, Rivian must support something above that.

 

[azbill]

I disagree.

If the vehicle supports SUSTAINED charging at OVER 200kWh then the vehicle would have to support HIGHER charge rates.

Let’s break it down.

1. Rivian says OVER 200kWh. That alone confirms MORE than 200kWh.

2. RJ has previously mentioned 300kWh. Things are subject to change, of course, but consider that it WAS said.

3. Rivian says SUSTAINED. Vehicles don’t charge at their MAX rate for sustained periods of time. In order to sustain 200kWh, Rivian must support something above that.

Yes, at 500A limit for the charger, they can achieve more than 200KW when the battery is above 50% SoC. But they will certainly not "sustain" that past 80%.

At 50% SoC the battery will be at 400V, assuming that is the nominal. 400V * 500A = 200KW. If they can sustain 500A out to 80% SoC, then that would be 430V * 500A = 215KW. So yes, they can sustain greater than 200KW between 50% and 80% in that case. But below 50% SoC they will be just under 200KW, because the battery voltage is less.

You state that vehicles do not charge at the max rate for very long, that is not a true statement. Audi E-Tron will maintain a relatively flat 150KW out to 70% SoC. Yes Tesla plays games with their very high rates compared to battery capacity, but other manufacturers do not. Even my Bolt charges at it's max rate up to 50% before it tapers.

 

[timesinks]

There is no point in implementing 500A charging if the vehicle is capable of accepting 800V.

What if the charger doesn't go up to 800V? Plenty of existing stations out there max out at 500V. Supporting the max amperage at 400V would improve your experience in that situation.

I'm not saying 400V-only isn't the most likely conclusion. But it is an unconfirmed extrapolation based on the information that's available, and that information leaves enough wiggle room to allow a different outcome from the generally accepted narrative.

I'm trying to be objective about what we do and do not know. I'm not convinced that there's enough authoritative information available to be certain of the voltages and charge rates.

 

[DucRider]

What if the charger doesn't go up to 800V? Plenty of existing stations out there max out at 500V. Supporting the max amperage at 400V would improve your experience in that situation.

There is no CCS standard for 200 kW 500V chargers (technically an FC50 could do that, but I don't know of any manufacturers that produce one)

For CCS compliance, a charger capable of even 300A will also be capable of 920V.
None of the EA installed "400V" chargers support 500A, and even the 150kW units can supply 800V.
The RAN specs on the Salida units indicate HPC250 compliant units (they can't supply the 350kW to earn the HPC350 designation)

If the charger won't go up to 800V, it also will not supply 500A.

An HPC150 charger like the EA 150 kW units would supply 135 kW to a vehicle like the Rivan with a 400V nominal pack.

An HPC250 could supply 225kW @ 450V, but it could also do it at 800+V.

I don't know of a charger on the market that can supply 200+kW at "400V" that is not also capable of "800V" charging.

Is it possible that Rivian is building to accept high power 400V charging in case there is a manufacturer that starts making them and a charging company/network that starts installing them? I guess. But the odds are close enough to nil to be counted that way. Since Rivian themselves are not installing that type of equipment, I don't see designing the vehicles to that spec.

Given what we know, 800V charging is off the table for the first releases.

 

[azbill]

None of the EA installed "400V" chargers support 500A, and even the 150kW units can supply 800V.

No longer true, here is a picture of a Signet 350KW dispenser, this is in Phoenix.

 

[timesinks]

Thanks for the chart. I was trying to find something like that but coming up blank.

 

[skyote]

No longer tru

No longer true, here is a picture of a Signet 350KW dispenser, this is in Phoenix.

You misunderstood. He was saying that only the chargers capable of higher voltage support 500A as well. Less than 500V don't support the higher amperage.

 

[DucRider]

Thanks for the chart. I was trying to find something like that but coming up blank.

No problem, full paper here:
https://www.charinev.org/fileadmin/Downloads/Papers_and_Regulations/CharIN_DC_CCS_Power_Classes.pdf

 

[azbill]

You misunderstood. He was saying that only the chargers capable of higher voltage support 500A as well. Less than 500V don't support the higher amperage.

Yes, I did misunderstand, but in fact I have never seen a 400V EA charger. The ABB ones I have used are all rated at 350A or 400A and 920V.

I have no idea where EA would have installed 400V chargers.

 

[DucRider]

You misunderstood. He was saying that only the chargers capable of higher voltage support 500A as well. Less than 500V don't support the higher amperage.

Exactly. I don't know of a charger that can do 500A that can't also do 900+V

Yes, I did misunderstand, but in fact I have never seen a 400V EA charger. The ABB ones I have used are all rated at 350A or 400A and 920V.

I have no idea where EA would have installed 400V chargers.

That was the point. There is nothing out there that can do the 500A @ 450V they were testing to that couldn't also do 250A @ 900V and get the same charge speed.
If the Rivians could accept an "800V" charge, there would be no need to build/test them to 500A.

 

[azbill]

Exactly. I don't know of a charger that can do 500A that can't also do 900+V

That was the point. There is nothing out there that can do the 500A @ 450V they were testing to that couldn't also do 250A @ 900V and get the same charge speed.
If the Rivians could accept an "800V" charge, there would be no need to build/test them to 500A.

At least I know where some chargers are close to my house where I can test it. Assuming there will ever be test drives ...

 

[mkennedy1996]

Apologies if this had been definitively confirmed elsewhere - I seem to recall some debate about 400 vs 800v batteries.
I saw this snap from the Rebelle R1T (via the auxiliary display manufacturer). Seems to confirm 400-450V.

It is still very possible that the LE vehicles will be able to accept an 800V charge. I am not saying that they will, but there is a way for this happen.

You just have to take a step back from the standard charging thought process and think outside the box.

This was discussed in 2018:
How does 800V charging work? – Electric Revs
"Another alternative is to build two 400V sub-packs that are connected together in parallel as one pack at chargers that are limited to 500V but connected in series for 800V at chargers that can handle the higher voltage limits. This dynamic reconfiguration of the internal pack connections can be done using giant relays called “contactors”. "

Rivian actually has filed a patent on this application:
Patent Suggests Rivian's Electric Trucks Will Charge Faster Than Rivals (insideevs.com)
Patent Images (uspto.gov)

 

[DucRider]

It is still very possible that the LE vehicles will be able to accept an 800V charge. I am not saying that they will, but there is a way for this happen.

You just have to take a step back from the standard charging thought process and think outside the box.

This was discussed in 2018:
How does 800V charging work? – Electric Revs
"Another alternative is to build two 400V sub-packs that are connected together in parallel as one pack at chargers that are limited to 500V but connected in series for 800V at chargers that can handle the higher voltage limits. This dynamic reconfiguration of the internal pack connections can be done using giant relays called “contactors”. "

Rivian actually has filed a patent on this application:
Patent Suggests Rivian's Electric Trucks Will Charge Faster Than Rivals (insideevs.com)
Patent Images (uspto.gov)

I completely understand that, but if they can accept 800V, there is no reason for the beefier wiring and other components required to accept 500A @ 450V. Any charger that can provide 200+ kW at 450V can also do it at "800V" (including the RAN chargers).

There is no 200+kW charger that is only capable of 400V charging, hence no reason to design for that unless the vehicle is not capable of accepting 800V.

 

[mkennedy1996]

I completely understand that, but if they can accept 800V, there is no reason for the beefier wiring and other components required to accept 500A @ 450V. Any charger that can provide 200+ kW at 450V can also do it at "800V" (including the RAN chargers).

There is no 200+kW charger that is only capable of 400V charging, hence no reason to design for that unless the vehicle is not capable of accepting 800V.

I don't see the 200+kW point! When you say there is no reason, what you are actually saying is that with information you have, you don't know of a reason to add the beefier wiring.

If you split the pack into 2 parts and charge each at 160kW, you get to the over 300kW that RJ mentioned.

At 400V, can you explain RJ's comment about being able to charge at over 300kW at the peak? if not, then either RJ was confused or there must be another explanation. This would be a way that could happen creatively.

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