skyote

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Do we know they’re different parts? Or has Rivian simply optimized the controllers and software?
They were 4 of the same motors at first & Rivian quoted separate front vs rear numbers more recently. It seems more likely to me that it's different HW, but I guess SW could be a possibility.





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DuckTruck

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I appreciate the suggestion of connecting Rivian and Whole Foods as this would likely pay dividends to both companies, along with Amazon. On the down side, from the maps provided in this video, the big hole in the Intermountain West won't be helped by this partnership.

On the other hand, ElectrifyAmerica has already developed a great partnership with Walmart. I'm assuming Walmart thinks there's value in enticing EV drivers to their stores to shop for a decent amount of time as they pass through their area. In the much more rural settings throughout the Rockies and Upper Plains, Walmarts are everywhere (see map).

If EA has no interest in growing this relationship, I would think others, including Rivian, could work a mutually beneficial arrangement with Walmart. If it's feasible for them to dedicate some of their parking in urban locations, the real estate expense in these rural areas would seem to be minimal. As some of these rural stores stand in more remote settings, the families stuck while their cars charge are even more of a captive audience.

I understand that VW had to serve penance for what they did and needed to spend big bucks as a result, but it would seem that the EA/Walmart blueprint really works. I get that the electrical aspects may be more difficult in these smaller settings, but I would think the long view would show this to be a winning proposition.

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R1S Maineiac

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Not DIRECTLY Rivian related, but I find it interesting that Hyundai is claiming 10%-80% SoC in 18 minutes on a 350kW stall with the 800v architecture for their new Ioniq. Granted, it's for a smaller battery, but still impressive. I suppose for the 180kWh pack, it would all depend on how long the pack can handled a sustained 300kW+ rate.....

https://www.techradar.com/news/hyun...anel-roof-and-the-ability-to-charge-other-evs
 

azbill

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Not DIRECTLY Rivian related, but I find it interesting that Hyundai is claiming 10%-80% SoC in 18 minutes on a 350kW stall with the 800v architecture for their new Ioniq. Granted, it's for a smaller battery, but still impressive. I suppose for the 180kWh pack, it would all depend on how long the pack can handled a sustained 300kW+ rate.....

https://www.techradar.com/news/hyun...anel-roof-and-the-ability-to-charge-other-evs
I calculated that rate, it is 200KW average rate to go from 5% to 80% for a 77KWH battery. That could mean a flat 200KW out to 80% or it could mean some curve from 350KW down to <100KW @80%.
 

R1S Maineiac

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I calculated that rate, it is 200KW average rate to go from 5% to 80% for a 77KWH battery. That could mean a flat 200KW out to 80% or it could mean some curve from 350KW down to <100KW @80%.

judging by the fact they specifically mention 350kW chargers twice, I'm guessing it's an average, probably with a similar curve to Tesla's (high rate <50%, tapering every 10% after that).

Quote from the article.
The 800v battery supports superfast charging too, with the Ioniq 5 able to reclaim 100km of range in just five minutes when plugged into a 350kW charger, while 10% to 80% happens in just 18 minutes.

Unfortunately, 350kW chargers aren't all that widespread at the moment, but a 50kW charger will be able to take you from 10% to 80% in an hour – and the Ioniq 5 wants to make sure it's a welcoming place to be while you charge.
 

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judging by the fact they specifically mention 350kW chargers twice, I'm guessing it's an average, probably with a similar curve to Tesla's (high rate <50%, tapering every 10% after that).

Quote from the article.
The 800v battery supports superfast charging too, with the Ioniq 5 able to reclaim 100km of range in just five minutes when plugged into a 350kW charger, while 10% to 80% happens in just 18 minutes.

Unfortunately, 350kW chargers aren't all that widespread at the moment, but a 50kW charger will be able to take you from 10% to 80% in an hour – and the Ioniq 5 wants to make sure it's a welcoming place to be while you charge.
In part because there is no CharIN (CCS) standard for a 300kW charger. The Kona, Niro and Ioniq EVs had charging times based on a 100 kW charger. Their max charge rate is 77 kW. The first owners of these vehicles thought there was something wrong because they did not get the full 100 kW they were expecting.

EA chargers are either 150 or 350 kW. You need to choose the 350 kW version to get the charge speed they are advertising.

There will almost certainly be taper, but this is not something I have seen any manufacturer publish. The charge curves we see only come from real world testing by owners or reviewers.

Note:
Current language on the 2020 Ioniq Electric
Approximately 54 minutes on a 100-kW DC Fast Charger and approximately 75 minutes on 50-kW DC Fast Charger. Charging rate and time estimate varies based on a number of factors, including current battery charge level, output of the charging unit, vehicle and battery settings and outside temperature.
I expect we'll see something similar for the Ioniq 5
 

n8dgr8

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Most of us are going to be lucky to get 50kw unless the non-Tesla manufacturers get together and compete with Supercharging.

I’m getting 400 mile rand to avoid fast charging altogether.
 

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Most of us are going to be lucky to get 50kw unless the non-Tesla manufacturers get together and compete with Supercharging.

I’m getting 400 mile rand to avoid fast charging altogether.
Interesting.
Most use cases for day trips and/or around town driving only won't require the extra range of the Max pack.
 

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Most of us are going to be lucky to get 50kw unless the non-Tesla manufacturers get together and compete with Supercharging.

I’m getting 400 mile rand to avoid fast charging altogether.
Electrify America has way more DFDCs (150Kw & 350KW) on the highways than the EVGO or ChargPoint low power (50KW) units. Most 50KW chargers today are only installed in metro areas, not along long range routes.

Having 400 mile range will not eliminate the occasionsal need for high speed charging.
 

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So I’ve heard that lots of DC fast charging can have a negative impact on long term battery health. Is that a binary thing with DC vs AC charging, or is it a linear thing where consistently charging at 350kW would be more harmful than charging at 150kW or 50kW?
 

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So I’ve heard that lots of DC fast charging can have a negative impact on long term battery health. Is that a binary thing with DC vs AC charging, or is it a linear thing where consistently charging at 350kW would be more harmful than charging at 150kW or 50kW?
There is no definitive answer, but one of the primary factors in battery degradation is heat. Getting batteries hot is bad. One of the reasons LEAFs with passive cooling showed issues in places like Arizona.
Thermal management is key, and Rivian likely has this covered.

But I also know a local Uber driver that put 170K miles on his passively cooled LEAF using primarily DCFC. He lost "bars" (battery capacity) at about the average for age, but a lot below the average for miles.

Battery health is a big factor in the charge taper we see, as is the reduced DCFC charge rates available at temperature extremes.

If you charge primarily on L2 at home and use DCFC on road trips, there should be no issue at all with the Rivians. If you cannot charge at home (or work) and rely exclusively on DCFC, there is more potential for accelerated battery capacity loss. This is one of the things that will remain unknown for (hopefully) a long time after Rivian starts shipping production units. Only if there is a severe problem is it likely to become apparent in the first years of ownership.
 

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I originally was told that frequent super charging for Tesla was not good but I think that is what the Battery Management System is created for. It monitors the load and battery temperature when charging and slows the charge rate to keep it in an optimal range. In real experience using Tesla Super Chargers over 5 years (probably over 95% of my charges have been Super Chargers), I lost 24 miles off of a 249 mile max (about 10%) and most of that was in the first 2 years. I think the battery management system should protect the battery regardless of the charger type you are using.

I'm sure Rivian will have a battery management system that will yield similar results.

The one thing I do adhere to is rarely charge over 90% unless going on a road trip. This allows the management system to rotate what 10% of the cells it wants to leave uncharged and is supposed to extend the overall life of the pack.
 

skyote

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Supposedly Rivian has some excellent battery management IP & it will learn how you drive and charge, then optimize for your usage patterns.
 

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The one thing I do adhere to is rarely charge over 90% unless going on a road trip. This allows the management system to rotate what 10% of the cells it wants to leave uncharged and is supposed to extend the overall life of the pack.
I don't know who told you that, but that's not the way it works. It's important to have the cells as equally charged as possible, and the BMS will actually do cell balancing periodically to achieve that. Charging to 90% charges the all the cells equally to lower voltage than a 100% charge does. Tesla allows you to charge to a higher level (% of max rated voltage for a cell) than any other manufacturer, hence their recommendation not to do it on a regular basis. Leaving 10% of the cells uncharged (completely discharged) is among the absolute worst things you could do to a battery pack.
 

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I don't know who told you that, but that's not the way it works. It's important to have the cells as equally charged as possible, and the BMS will actually do cell balancing periodically to achieve that. Charging to 90% charges the all the cells equally to lower voltage than a 100% charge does. Tesla allows you to charge to a higher level (% of max rated voltage for a cell) than any other manufacturer, hence their recommendation not to do it on a regular basis. Leaving 10% of the cells uncharged (completely discharged) is among the absolute worst things you could do to a battery pack.
You are correct, I am mixing my battery management system with the SSD drive management system which rotates the writes to improve longevity.

Real take away for me though is I was pleasantly surprised to still have 90% of my battery after 5 years, especially since Tesla warranties 70% in 8 years before they call it bad.
 

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