Max Pack Battery Capacity Confirmed - 149kWh

[Epicloop]

So efficiency plays a part but battery chemistry does too since you get 50 miles from an additional 15kWh.

IF the C&D claim of 149kwh is correct it must be the "useable" capacity.
I highly doubt there is enough magic in there to get 58 miles out of 14kwh.
58/14=4.14m/kwh
No one is getting anywhere close to 4m/kwh.
It is looking like a 20kwh pack increase to me. This translates to a 25% increase in the 20-80% charging range.

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[mkhuffman]

IF the C&D claim of 149kwh is correct it must be the "useable" capacity.
I highly doubt there is enough magic in there to get 58 miles out of 14kwh.
58/14=4.14m/kwh
No one is getting anywhere close to 4m/kwh.
It is looking like a 20kwh pack increase to me. This translates to a 25% increase in the 20-80% charging range.

I agree. It is 20 kWh added, not 15.

 

[NY_Rob]

There other ways to get more kWh out of a cell and/or battery pack then just using higher capacity cells...

All cells have an absolute max charge voltage and min cutoff voltage recommended by the cell manufacturer. If you charge the cell to absolute max voltage, then discharge it to absolute min voltage... you should get the advertised amp hour rating out of the cell as long as you don't exceed the cell's 1C current rating.
With that in mind, no EV manufacturer drive their cells that hard, ie charging to absolute max voltage and discharging to absolute minimum cell cutoff voltage as they are interested in persevering pack life till at least past the 8 or 10 year warranty.

So, if the cell manufacturer recommended max cell voltage is 4.2V and min cell voltage is 2.5V delivering 2600mAh, but in an effort to get the longest cell life the EV maker has capped charging the cells to 3.9V and discharging the cells to 2.8V now you only derived 2100mAh out of each cell.
At some point if you want to squeeze a bit more energy out of your pack to make customers happy... you increase your previous max cell voltage from 3.9V to 4.1V and decrease the low cutoff voltage from 2.8V to 2.6V (and you are still within manufacturer absolute limits) you instantly get increased kWh capacity out of the existing pack especially when considering multiplying the individual cells increased energy output by 7,776 cells (in the large pack) and even more in the max Pack.

Tesla has done exactly that when they used larger packs but de-rated them for specific lower priced/range vehicles and even on a temporary basis (IIRC it was due to a hurricane in FL?) to "unlock" the full kWh potential of it's packs for owners needing max range to evacuate.

Of course, Rivian could be using higher capacity cells in the max packs.. but also driving them a bit harder (closer to their absolute min and max cutoff voltages) in comparison to the cells in their large packs.

 

[Throwdown]

This report re-confirms straight from rivian that they added no additional cells for the max pack, 149kwh gross, but said rivian has not stated usable size to them. Enjoy
https://www.autoevolution.com/news/...-and-more-about-clever-efficiency-222394.html

 

[vandy1981]

That seems like a rational conclusion.

This report re-confirms straight from rivian that they added no additional cells for the max pack, 149kwh gross, but said rivian has not stated usable size to them. Enjoy
https://www.autoevolution.com/news/...-and-more-about-clever-efficiency-222394.html

I don't think there's primary sourcing about the battery in that article, FWIW. This InsideEVs article directly quotes Rivian's communication with them. It confirms what Car and Driver reported earlier and what's repeated in the autoevolution article.

 

[Joel]

Yes because 180 kWh would deliver much more than 400 miles of range, instead of barely making it. 2.75 mi/kWh x 170 kWh usable = 468 miles. Now THAT is worth $10k for sure, right?

Yes I would have still held out for the Max pack and also kept my other reservation.

 

[Throwdown]

I don't think there's primary sourcing about the battery in that article, FWIW. This InsideEVs article directly quotes Rivian's communication with them. It confirms what Car and Driver reported earlier and what's repeated in the autoevolution article.

That was more for the people that don't think it's a 149kwh pack

 

[vandy1981]

Yes because 180 kWh would deliver much more than 400 miles of range, instead of barely making it. 2.75 mi/kWh x 170 kWh usable = 468 miles. Now THAT is worth $10k for sure, right?

In that scenario your battery pack probably would have been at least 600 pounds heavier and that would be reflected in a near-1000 pound payload capacity. You also would not have made anywhere close to 2.75 mi/kWh. And that's not even considering the negative implications that weight would have on chassis dynamics.

 

[vandy1981]

That was more for the people that don't think it's a 149kwh pack

That's why I referenced a primary source. So there shouldn't be any doubt if two news outlets are quoting direct and independent confirmation of 149 kWh.

 

[Epicloop]

That's why I referenced a primary source. So there shouldn't be any doubt if two news outlets are quoting direct and independent confirmation of 149 kWh.

So only another 14 miles while towing larger/heavier loads , my primary towing route is 160 miles.

 

[vandy1981]

So only another 14 miles while towing larger/heavier loads

It doesn't necessarily work that way. The efficiency hit should be proportional to the efficiency of the tow vehicle.

 

[Supratachophobia]

That's why I referenced a primary source. So there shouldn't be any doubt if two news outlets are quoting direct and independent confirmation of 149 kWh.

And I've been told they are using 5200mah Samsung cells so that puts it right in there at 146 usable-ish. Take that info for whatever it's worth.

 

[R1TS]

And I've been told they are using 5200mah Samsung cells so that puts it right in there at 146 usable-ish. Take that info for whatever it's worth.

If it is indeed 149 kWh gross, it seems awfully close to the limit to be allowing 146 kWh usable, no? The large pack has a 6 kWh buffer.

 

[Supratachophobia]

If it is indeed 149 kWh gross, it seems awfully close to the limit to be allowing 146 kWh usable, no? The large pack has a 6 kWh buffer.

They must feel they can get away with 3-4kwh vs. 6.

Pretty slim, I know. But they needed to get this max pack out and get these pre-price-hike orders off their books.

 

[scottf200]

The battery is just a storage medium...how can it increase the efficiency of the vehicle?

If ABRP is correct, then the max pack could still have an advantage on long road trips. ABRP has both DM Large and DM Max at 2.68 mi per kwh @65. It appears, and I have an email into them, that they have the correct max pack capacity. If I multiply 2.68 by 149 I get 399 and 142 gives me 380.

With the ABRP calcs all things appear equal the extra power over a long road trip equates to less time charging. On a 430 mile trip it saves 15 mins charging time and on a 900 mi trip it saves 54 mins. When towing it appears to save even more time....8 charging stops vs 12 for large on a 900 mi trip. I posted my ABRP trip plans here:

https://www.rivianforums.com/forum/threads/my-opinion-on-max-pack-offering.19777/post-408493

This is going to require some real world testing. I still think its probably not worth it for most, but folks with certain use cases may be able to justify it a little easier.

2.68 x 129 kwh usable for large - 345 mi range
2.68 x 142 kwh usable for max - 381 mi range

A difference of 36 miles, BUT.....on a long road trip this results in less time spent charging according to ABRP.

A little more math:
352/129 = 2.73 miles per kWh
410/142 = 2.89 miles per kWh
410/149 = 2.75 miles per kWh

Maybe Car and Driver is incorrect regarding the usable capacity. They were told the capacity is 149 kWh, and they estimated the usable capacity. What if they misunderstood and what they were told is actually the usable capacity? Then the numbers make more sense.

Or, is Rivian becoming less conservative, and maybe using the EPA test cycle that Tesla uses to justify 410 miles of range? Does it make sense that the max pack is more efficient than the large pack? It doesn't make sense to me.

410 miles in the Rivian with a 149 kWh battery indicates that they’re doing something with the batteries that others can’t. That means Rivian has some technology that is more advanced than anyone else, including Tesla. That’s a really, really good thing for the future of Rivian.

Thanks for the comparison numbers.
I've been trying to put together a spreadsheet to see how all the trucks compare.
Are there other spreadsheets/tables out there?

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