Max vs. Large battery Physical Location?

[DucRider]

There was some chatter and a patent where two batteries operated at 450V in parallel when driving and then in series at 900V to charge. I'm hoping that's a difference between large and max packs. I would love to get near that 350kW charge rates that Porsche has.

No, it is a method of internally reconfiguring the battery on the fly and will apply to all of the pack sizes. It will be implemented later OTA when they boost the DCFC speed (they can't do the claimed 300 kW without upping the charging voltage).

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[electrictaco]

Why would they make it a different voltage?that would mean changing much of the electrical system. It’s just bigger.

Well actually, if they add a parallel set of batteries in series to the Large pack to make a Max pack, the voltage will go up. Not to 800V unless they doubled the entire pack size, but it would go up.

 

[crashmtb]

There was some chatter and a patent where two batteries operated at 450V in parallel when driving and then in series at 900V to charge. I'm hoping that's a difference between large and max packs. I would love to get near that 350kW charge rates that Porsche has.

Why would they not do that with the lower kWh battery too, then?

 

[electrictaco]

It will be implemented later OTA when they boost the DCFC speed (they can't do the claimed 300 kW without upping the charging voltage).

In order for an OTA update to work for 300kW charging, the vehicle would have to come with really high amperage internal wiring from the get go (probably greater than 725A at least). Then the charging cables themselves would have to also be rated to a much higher amperage as well.

I've also noticed that any references to 300kW charging on Rivian's website are always in reference to the Rivian Adventure Network, and not directly speaking about either the R1T or the R1S. So I think they are saying that the network will eventually charge that fast, but not necessarily the first trucks.

 

[nfrank]

Why would they not do that with the lower kWh battery too, then?

I guess they could depending on their cell voltages and pack configurations. And if they could do it with the Large pack, why not give the functionality from the get-go? Maybe they're just going to baby the battery management system until they get it all figured out. Not sure. Wish I knew.

 

[DucRider]

In order for an OTA update to work for 300kW charging, the vehicle would have to come with really high amperage internal wiring from the get go (probably greater than 725A at least). Then the charging cables themselves would have to also be rated to a much higher amperage as well.

I've also noticed that any references to 300kW charging on Rivian's website are always in reference to the Rivian Adventure Network, and not directly speaking about either the R1T or the R1S. So I think they are saying that the network will eventually charge that fast, but not necessarily the first trucks.

No
Higher voltage = lower amperage and lighter wires (for any given kW value)
Going from the ~200 kW @ 450V charging to 300 kW @ 900V would be done at a lower amperage

 

[electrictaco]

No
Higher voltage = lower amperage and lighter wires (for any given kW value)
Going from the ~200 kW @ 450V charging to 300 kW @ 900V would be done at a lower amperage

Yes, but how are you upgrading the battery pack from 450V to 900V OTA?

200kW @ 450V = 444 A
300kW @ 450V = 666 A

 

[Autolycus]

Well actually, if they add a parallel set of batteries in series to the Large pack to make a Max pack, the voltage will go up. Not to 800V unless they doubled the entire pack size, but it would go up.

Batteries in parallel do not stack voltage.

The large and max packs will have the same voltage. The large pack has 9 modules. The max pack will be created by adding 3 additional modules in parallel with the 9 other modules.

 

[thrill]

Yes, but how are you upgrading the battery pack from 450V to 900V OTA?

200kW @ 450V = 444 A
300kW @ 450V = 666 A

Electronically enable/disable the appropriate shunt relays between the modules to reconfigure the forward array, err, alter a 450V system to an 900V system. I have no actual idea how it's designed, but I'd think being able to electrically isolate modules would be a "good thing" from a BMS anyway.

 

[electrictaco]

Electronically enable/disable the appropriate shunt relays between the modules to reconfigure the forward array, err, alter a 450V system to an 900V system. I have no actual idea how it's designed, but I'd think being able to electrically isolate modules would be a "good thing" from a BMS anyway.

This is what the patent was kind of trying to do I think. But I highly doubt it made it into the first generation of trucks, or else we would be hearing about it in the advertising.

 

[Max]

Does all of this mean if I get a large pack and realize in two years I really need that max pack, it would be impossible or much more expensive to upgrade?

Another newbie question: why do I need a wall charger? Doesn't Rivian come with a cable to plug into my NEMA 50?

 

[DucRider]

Does all of this mean if I get a large pack and realize in two years I really need that max pack, it would be impossible or much more expensive to upgrade?

Another newbie question: why do I need a wall charger? Doesn't Rivian come with a cable to plug into my NEMA 50?

Upgrading to a max pack later is not an option (and has nothing to do with voltages)

Yes, you can use the included cable to plug into a 14-50 (if you have a 6-50 it may be an issue). It will charge at 32A.
Some people like to keep the portable EVSE in the vehicle and coiling and storing it becomes a chore rather quickly. A wall mounted EVSE can charge 50% faster and they often have additional features.

 

[DucRider]

This is what the patent was kind of trying to do I think. But I highly doubt it made it into the first generation of trucks, or else we would be hearing about it in the advertising.

They've stated that 300 kW charging would be enabled OTA. 300 kW charging requires "800V" with the RAN equipment they are installing (and all the existing EA equipment as well)

 

[SeaGeo]

They've stated that 300 kW charging would be enabled OTA. 300 kW charging requires "800V" with the RAN equipment they are installing (and all the existing EA equipment as well)

Do you know where they said this? I've seen the mention that RAN will go to 300 kW eventually, and RJ mentioning off in an interview they will eventually get there but not the first vehicles (this was a couple years ago). I'm just cautiously hopeful you're right. Seeing the Taycan crank out 270 kW at 50% SoC and the Ioniq five go north if 200 easily with half the size of battery definitely gives me some semi-irrational charging speed lust.

 

[Autolycus]

Do you know where they said this? I've seen the mention that RAN will go to 300 kW eventually, and RJ mentioning off in an interview they will eventually get there but not the first vehicles (this was a couple years ago). I'm just cautiously hopeful you're right. Seeing the Taycan crank out 270 kW at 50% SoC and the Ioniq five go north if 200 easily with half the size of battery definitely gives me some semi-irrational charging speed lust.

Yeah, I've seen mention of something like "will get up to 300kW with later updates", but I don't think it should be assumed by anybody that that means OTA software/firmware updates. That is at least, if not more, likely to mean updates to the vehicle and/or charger design being built.

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