ajdelange

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CS agent today told me the emphasis of the Large vs Max pack is in miles of range, not kWh, AND that the kWh may have changed from the 135/180. He didn't say it had changed, but MAY have changed. Hard to say if he really knew, but emphasis on miles per pack at this point.
They can change the kWh simply by changing how they define empty and full without changing a thing in the battery pack itself. Also keep in mind that you can't just change the pack arbitrarily. There is a minimum delta that depends on the configuration of the pack.

Now an improvement in the batteries realized by the cell manufacturer since the 135/180 numbers were published is possible. But clearly no information on the actual battery capacities will be forthcoming.





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Autolycus

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On battery pack capacity...

1) Unless they've made a surprising change to their module and pack designs, we know they're using 864 cells per module and 9 or 12 modules for the "large" and "max" packs, respectively.
2) We know with certainty that they're using Samsung SDI cells.
3) Samsung introduced cylindrical NCA cells with 91% nickel just this month. The announcement indicated that those cells were already in production, and there's some evidence that they may indeed be the cells Rivian is purchasing: https://insideevs.com/news/513181/samsungsdi-cylindrical-nca-cells-91nickel/
4) Those Samsung cells are rated at 18.15Wh. 864 of them would make a module capacity of 15.68kWh. 9 modules would have a capacity of 141.1kWh, not 135. 12 modules would have a capacity of 188.2kWh, not 180.

As has been noted in various threads, there are lots of good reasons for all EV manufacturers to stop mentioning the kWh of their packs. The most obvious is that it gives them some flexibility in pack size as new battery tech comes out. Another obvious one is that it gives them some flexibility on how much of the battery's full capacity is actually available to customers, which could important to protect the battery from use scenarios that could damage the cells, or worse, cause a fire.

When they were pushing 135kWh/180kWh, they may not have been certain they'd be able to get this newer 91% nickel cell. Or they could have always planned to have these but were going to leave the extra 6/8kWh as a buffer. Or maybe they've realized they need a bigger buffer to be safe in the extreme usage conditions they're planning around. Or maybe they've decided they don't actually need the full 135/180 to get the range they want, so they're going to use an even bigger buffer for extra safety margin. In any event, it no longer makes sense for them push the 135/180 numbers because all the buyer ever really cared about was the range anyway.
 

Autolycus

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They can change the kWh simply by changing how they define empty and full without changing a thing in the battery pack itself. Also keep in mind that you can't just change the pack arbitrarily. There is a minimum delta that depends on the configuration of the pack.

Now an improvement in the batteries realized by the cell manufacturer since the 135/180 numbers were published is possible. But clearly no information on the actual battery capacities will be forthcoming.
As I just noted, we have a pretty good reason to believe the cells they're using are Samsung SDI's recently announced 91% nickel cylindrical NCA cells with a listed capacity of 18.15Wh. We obviously don't know what they might have been planning around before though. It could likely have been Samsung's 88% nickel cells which were the main option from Samsung until this year. My very quick search is not having much luck finding the capacity of the previous generation cell. I am only finding capacities for the 18650 cells.

EDIT: It looks like the previous generation of cells were rated at 4900mAh, so 17.64Wh. That would mean packs that are 137.2kWh and 182.9kWh if the cells I'm finding for sale (50e) are the ones Rivian may have originally been planning around.
 
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ajdelange

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Didn't see what you posted as you posted it while I was typing.

I'll point out again that the "capacity" of a battery is not just a number. If you look at the spec for this new cell it is 18.15 Wh (5.0 Ah; 3.63 V). Note that the upper limit of the range is specified. What was the lower limit? How do we know that Rivian will charge them to 3.63V or discharge them to whatever lower voltage was used in arriving at the 18.15 Wh spec.

12 modules would have a capacity of 188.2kWh, not 180.
Yes, if Rivian charges them all the way up to 3.63V and discharges them down to the same Vmin. Suppose they decide to charge up to to only 3.5 V and increase battery life. Or go up to 3.63 and discharge down to 1.1*Vmin instead of Vmin for some miles in reserve even when the gauge says empty? These actions or a combination of them will change the amount of energy available between empty and full and they are at the control of Rivian. Then there is the question as to whether what they might report to us is number cells times the manufacturers 3.63V spec (even though they may not choose to go that high) or the usable (available) capacity. This flexibility is great in terms of the OEMs ability to make engineering trades but it is fertile ground for misinterpretation and even lawsuits.
 
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BoltEVowner

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Very interesting. We can hope that Rivian indeed is already using the higher energy 50G SDI cells for their packs. This would likely give a nice buffer, greater than 135/180 kWh potential, conservative enough to get 300+/400+ miles easily/safely, all depending on how aggressive/conservative Rivian is at allowing percentage of available power. No lawsuits or warranty battery pack replacements. And over time, with an OTA software update, they could allow greater range if safety and longevity analysis warrants it. Maybe Rivian will divulge/leak more information in the months ahead. Right now, bet only RJ and a select group have knowledge of the final battery pack details. But it is crunch time and the deciders need to decide, and the producers need to produce. Full speed ahead!
 

ajdelange

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(5.0 Ah; 3.63 V).
4) Those Samsung cells are rated at 18.15Wh. 864 of them would make a module capacity of 15.68kWh. 9 modules would have a capacity of 141.1kWh, not 135. 12 modules would have a capacity of 188.2kWh, not 180.
We can play guessing games all day about this. Supposing they decide that the basic block is 28 cells in series. It is then a 101.6 V, 0.5082 kWh block. Seems sort of convenient. You put 4 of them in series to get 406.4 V and 2.0328 kW. Paralleling 90 of these groups gives 182.952 kW and switching that to 2 series groups of 45 each gives the 812.8 V needed for high power charging.

28 cells seems nice because they can be arrayed 7X4, but 27 can be arrayed 9x3 which isn't bad either. Arranging 90 blocks of these in the same way gives a total pack capacity of 176.4 kWh. Thus the capacity changes that are possible depend on the topology. Then there are the games they can play with V_empty and V_full. Best they keep all this under their hats.

I remember getting a letter from a law firm asking if I wanted to join a class of consumers who had bought 25" monitors from a well known manufacturer. They had measured them and found they were 24.9". BTW, if you have never gotten one of these letters the way they work is that the company works out a settlement in which they agree to a settlement worth several millons with the law firm claiming a third or so in fees. The rest goes to the class in the form of a coupon for a discount on the next monitor they buy. This is the world we live in. You are probably aware of what Hindenburg did to Nikola and subsequently to Workhorse.
 

Mysta

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Haven't they been taking portable chargers on some of their testing too?
 

intimidator

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Hello all,

Long time lurker here posting for the first time. Like all of you, I've been tracking Rivian pretty close over the last couple of years and the obsession has only grown. I tend to parse through new content pretty closely and came across a flicker of estimated range on the instrument cluster in the latest Rivian story about the interior:


That's 303 miles. This is a screenshot taken from the video that plays on loop at the top of the story.

Departing between 9:00 am and 9:30 am and after a drive of roughly 2 hours and 129 miles, they arrive on Basin Junction road with 303 miles left around 11:24 AM (displayed above on the instrument cluster for range and the center display for time). This would give the vehicle they are driving a total range of roughly 432 miles, which is a reasonable range estimate for the Max pack. I assume that they would be driving a vehicle with the Max pack since they were on a pretty long road trip.
You have way too much time on your hands :) LOL
But thank you!!

If the max pack can do 430 miles on a charge I will be delighted. Now, I just have to get mine.....come on January!
 

ajdelange

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Well sometimes it will but most of the time it will do something like 340. Not that you would ever run it from 100% to 0%.
 

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Remember when the official EPA numbers were a few weeks away? Good times.

I'm not super concerned about most things (like much of this forum) but I am concerned that the EPA results didn't go well and they are delaying / scrambling, as I suspect this would be a death blow.
 

SANZC02

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Remember when the official EPA numbers were a few weeks away? Good times.

I'm not super concerned about most things (like much of this forum) but I am concerned that the EPA results didn't go well and they are delaying / scrambling, as I suspect this would be a death blow.
I am not as concerned about the range numbers. I think they will be in the range of what they have been estimating.

They have been putting thousands of miles on these test mules over the last 18 months. If the numbers were going to be way off and not attainable, they would have adjusted the estimated range on the web site.
 

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Remember when the official EPA numbers were a few weeks away? Good times.
I actually don't remember!

Is this one of those things on this forum where someone planted an idea of what they hoped/suspected would happen, and the mob-brain ran with it?

Or did Rivian actually officially announce that EPA numbers would be released to the public in a few weeks?

If the later, I'd honestly missed it and would love to learn more about when that was.
 

LaunchGreen

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I actually don't remember!

Is this one of those things on this forum where someone planted an idea of what they hoped/suspected would happen, and the mob-brain ran with it?

Or did Rivian actually officially announce that EPA numbers would be released to the public in a few weeks?

If the later, I'd honestly missed it and would love to learn more about when that was.

I think it may have been CS. Let me see if I can find it.

I wonder if it's even legal to sell vehicles that haven't completed EPA testing? Deliveries start in the next 30 days and were pushed back - it seems to me that they would be cutting it awfully close to have not completed the testing and counting on a government agency to move quick. I suppose their website does say "pending review" which could mean their own review ;)
 
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