Took Delivery of our R1S Performance Dual Motor Max Pack!

[vandy1981]

That would mean the DM Max Pack is more efficient than the DM Large Pack. Which doesn't make sense.

Why are you assuming that a different battery pack chemistry can't have better efficiency?

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[mkhuffman]

Why are you assuming that a different battery pack chemistry can't have better efficiency?

Because that is not where the inefficiency is located. It is located in the drive train and most importantly rolling and air resistance. The DM drive train efficiency improvements are already in the Large Pack models, and there are no aerodynamic changes. (Disconnecting one of the motors is a good idea to improve efficiency, but even that is minor compared to air and rolling resistance.)

If you can point to a data based article/report that has shown a measurable improvement in mi/kWh just due to battery efficiency improvements I might believe it. In the meantime, no way.

 

[vandy1981]

Because that is not where the inefficiency is located. It is located in the drive train and most importantly rolling and air resistance. The DM drive train efficiency improvements are already in the Large Pack models, and there are no aerodynamic changes. (Disconnecting one of the motors is a good idea to improve efficiency, but even that is minor compared to air and rolling resistance.)

If you can point to a data based article/report that has shown a measurable improvement in mi/kWh just due to battery efficiency improvements I might believe it. In the meantime, no way.

As an example, different battery chemistries will have different internal resistance and will generate different amounts of heat with charge/discharge. If less energy is spent conditioning the battery, more will be available for traction.

This isn't related to battery chemistry, but it is also possible that the efficiency of the components in the max pack is higher so more energy from the stated capacity can flow to the wheels.

We really need a teardown of the Max Pack to see exactly what we're dealing with.

Edit: Higher battery energy efficiency would also lead to increased recouperation of energy from regeneration.

 

[BrentInCO]

Per Rivian, there’s the same # of battery cells; those cells just can hold more energy, so there’s more kWh stored. So the max pack vehicle can drive farther than the large pack until it runs out of energy. Same mile / kWh efficiency. Isn’t it that simple?

Just to illustrate:
2.7 miles / kWh x 130 kWh = 352 miles
2.7 miles / kWh x 148 kWh = 400 miles

 

[mkhuffman]

As an example, different battery chemistries will have different internal resistance and will generate different amounts of heat with charge/discharge. If less energy is spent conditioning the battery, more will be available for traction.

This isn't related to battery chemistry, but it is also possible that the efficiency of the components in the max pack is higher so more energy from the stated capacity can flow to the wheels.

We really need a teardown of the Max Pack to see exactly what we're dealing with.

All that could be true but for it to translate into a measurable mi/kWh improvement on the road the battery improvements need to be dramatic. I doubt Rivian has made such a significant leap in battery efficiency, but I guess anything is possible.

I think it is more likely they changed the EPA test conditions to break the 400 mile threshold. That is if the usable capacity is 142 kWh instead of 148 kWh. At 148 kWh the math works out between the Large and Max.

 

[Ronaldinho]

All that could be true but for it to translate into a measurable mi/kWh improvement on the road the battery improvements need to be dramatic. I doubt Rivian has made such a significant leap in battery efficiency, but I guess anything is possible.

I think it is more likely they changed the EPA test conditions to break the 400 mile threshold. That is if the usable capacity is 142 kWh instead of 148 kWh. At 148 kWh the math works out between the Large and Max.

Agreed, but that's why we're impatiently waiting for the detailed EPA test data to be released. Because, at least according to the window stickers, the max pack dual motor IS more efficient than the large pack dual motor. We just don't know how or why yet.

If I'm reading this correctly, this CARB document appears to show the unadjusted city cycle (UDDS) range for each max pack variant?

https://ww2.arb.ca.gov/sites/defaul...06/pc-ldt-mdv_mdpv_a-480-7__sdt--20230814.pdf

 

[mkhuffman]

Agreed, but that's why we're impatiently waiting for the detailed EPA test data to be released. Because, at least according to the window stickers, the max pack dual motor IS more efficient than the large pack dual motor. We just don't know how or why yet.

If I'm reading this correctly, this CARB document appears to show the unadjusted city cycle (UDDS) range for each max pack variant?

https://ww2.arb.ca.gov/sites/default/files/classic/msprog/nvepb/executive_orders/EO Web Files/PC-LDT-MDV/2023/0006/pc-ldt-mdv_mdpv_a-480-7__sdt--20230814.pdf

I am not sure the EPA test data will help us understand why, unless we can tell they tested it differently than they tested the Large Pack.

@Jiji said he is able to use the Rivian API to read the battery capacity, and he is waiting for someone with a Max Pack to allow him access so he can check it. He says the Large Pack is 127 kWh usable.
https://www.rivianforums.com/forum/...over-black-mountain-88k-obo.19707/post-421762

 

[HighVoltOverland]

Because that is not where the inefficiency is located. It is located in the drive train and most importantly rolling and air resistance. The DM drive train efficiency improvements are already in the Large Pack models, and there are no aerodynamic changes. (Disconnecting one of the motors is a good idea to improve efficiency, but even that is minor compared to air and rolling resistance.)

If you can point to a data based article/report that has shown a measurable improvement in mi/kWh just due to battery efficiency improvements I might believe it. In the meantime, no way.

ONE battery.
Dual chemistry battery in Tesla (model S?), same footprint, effective range of 750 miles for a single charge.
No change to the aero or footprint of the vehicle.
They actually have a working product, not a video of vaporware rolling down a hill.

BMW is putting eggs in the companies basket.

https://one.ai/products/gemini

YouTube Matt Ferrell Undecided just did a good video on the potential of the product

 

[mkhuffman]

ONE battery.
Dual chemistry battery in Tesla (model S?), same footprint, effective range of 750 miles for a single charge.
No change to the aero or footprint of the vehicle.
They actually have a working product, not a video of vaporware rolling down a hill.

BMW is putting eggs in the companies basket.

https://one.ai/products/gemini

YouTube Matt Ferrell Undecided just did a good video on the potential of the product

The capacity is why it can provide longer range, not efficiency. They list it as 185+ kWh. So more than 185 kWh in a Model S will make it go very, very far.

 

[HighVoltOverland]

The capacity is why it can provide longer range, not efficiency. They list it as 185+ kWh. So more than 185 kWh in a Model S will make it go very, very far.

The capacity is because of the change in chemistry though.
They didn't just duct tape an extra 100 cells in the back seat and the frunk.
The battery was in the same form factor of the OEM Tesla battery

The battery system has an energy density of 416 Wh/L (compared to approximately 245 Wh/L of the original pack)

That energy density improvement was achieved by using an alternative chemistry in conjunction with LFP.

 

[mkhuffman]

The capacity is because of the change in chemistry though.
They didn't just duct tape an extra 100 cells in the back seat and the frunk.
The battery was in the same form factor of the OEM Tesla battery

The battery system has an energy density of 416 Wh/L (compared to approximately 245 Wh/L of the original pack)

That energy density improvement was achieved by using an alternative chemistry in conjunction with LFP.

Yes. But the key is higher capacity. The efficiency of the MS doesn't change, but it goes farther because it has more kWh.

I hope this technology turns out to be as good as they say, because this is exactly what we need.

 

[HighVoltOverland]

Yes. But the key is higher capacity. The efficiency of the MS doesn't change, but it goes farther because it has more kWh.

I hope this technology turns out to be as good as they say, because this is exactly what we need.

These responses are too pedantic for me to care.

More miles, same size box. Technology good.

 

[vandy1981]

We drove from Nashville to check out the new Cookeville RAN station today. It was a seamless experience and the session was free. I will gladly pay for electrons at these stations for a seamless and reliable experience like this. I got 95 kW from 60%-75% and it dropped down to 49 kW at 75%.

Efficiency was great coming from the Lightning--we got 2.35 mi/kWh roundtrip mostly at 75-80 mph. Ambient temperatures were in the 70s. We probably would have been in the 2.0-2.1 mi/kWh with the Lightning on that same route.

I also saw an R1S going in the opposite direction on the highway that was towing a flat bed with two large round bales of hay which was pretty cool.

 

[Supratachophobia]

352/128kwh= 2.75
410/2.75= 149>142kwh usable

So if that's the case, I think Im going to eventually be ok with it. I don't like the cost certainly. And I definitely don't like the secrecy.

But if they are giving the same 7kwh buffer on both and using the same w/m or m/kw to get their numbers on both, then it is what it is.

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