800v Architecture R3 series

[Hereforthesnacks]

Ditto. Too much attention on cells and platform architecture. Charging infrastructure is the third part of equation. 800V and newer cells can only shave 5-10 minutes or so per session under ideal conditions. To truly have the 5-10 minute session times that are starting to roll out in China you’d need the chargers and a grid that can deliver. And without authority of government behind that, not easy to achieve any time soon. Our governing culture can’t even agree on what is fact vs opinion. To get a unity in policy on charging/grid standards?! Good luck.

I don’t know where you are getting your math. How long does it take to fast charge 10-80 on an R1? Let’s simplify it and not go battery by battery. Just average time’ish. 40-45 minutes?

A 100kwHr battery on 800V under good (not ideal, but good) conditions takes about 24 minutes. That’s almost half the time.

This concept of shaving only 5-10 minutes isn’t tied to real world data. Not for the R1 at least.

The 800V charging experience is a lot better. Is it worth focusing on for Rivian? I don’t know. Solid state batteries will be much faster, with better range and lifespan. Rivian is in survival mode, so if they can actually get to solid state before competitors, that’s the way to go and they can skip over 800V.

Regardless, it’s better to have a convo based on real world facts, not fiction.

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[OpalescentIceytea]

I agree that Rivian should eventually make the move over to a 800V system. However, currently the largest charging network in the US, Tesla, only really supports 400v systems(their v4 stalls being the exception). Same for their biggest seller, the Y.

 

[Nixapatfan]

At some point Rivian will need to update to 800v even if they don't think it is worth it, when most of your competition will be marketing 800v and you still want to look like you are an EV front runner you have to keep up with the arms race.

Going to 800v is not some technical breakthrough it is mostly how things are wired up and inverters to support higher voltage in the grand scheme of things it's not a huge undertaking like solid state batteries, on a new design they should be able to accommodate though I don't see that happening for R3 as that will mostly be an R2 with a different body.

 

[BCondrey]

DCFC speed is a big nothingburger for me. Its a very small percentage of my charging. I'd rather have better efficiency / more miles.

 

[VSG]

So, what's the next step?

Going from 400V to 800V will get you to AT BEST twice the charging speed, when all cars and all chargers support it.

Does that solve the problem? I think all the people who complain about charging speed won't be satisfied until charging is just as fast as filling a gasser (which BTW is just an arbitrary metric, something we're used to as opposed to a number that we deliberately chose based on real need). And twice as fast just won't cut it. It's going to have to be 10 times as fast.

So do we go from 800V to 1600V next, and change all the vehicles and all the charging infrastructure over the next 10 years? That still doesn't get to 10 times as fast as we currently have, it's only 4 times as fast as 400V. And at what cost in terms of money and infrastructure and time?

Increasing the voltage helps, but it's just not scalable if your goal is to make EV charging as fast as ICE fueling - we will never get there with this strategy.

So consider that it might be a wise business decision to stick with 400V for now, on the current mid-priced R2 platform, if Rivian is forward-thinking and looking towards some technology that scales better, like solid-state batteries or a different chemistry or any of the other things the Chinese have used to increase charging rates from ~1C up to ~10C. Those might be far more bang for the buck and far more future-proof than an 800V system.

 

[Zathras]

if anyone has been paying any attention to the charging situation in China you will know there is an ongoing charging speed war amongst several carmakers in that rapidly evolving country.

IMO Rivian MUST 100% focus on making the R3 platform the first Rivin product using an 800v or more architecture. This could coincide with an R1 and R2 refresh cycle which also would switch to 800v. Just today FAW China unveiled a laboratory battery charging at a ridiculous 3 minutes 40 seconds to 70% charge and >90% in under 6 minutes. This is literally gasoline fueling speed. Already in China giants like BYD have deployed real world charging at 12c or 80% in 6 minutes or so. When the order form for an R3X comes online I will jump regardless but many normies will hesitate if the old EV bugaboo about 80% in 30 minutes is still an issue in 2028 or 2029.

I’m not going to worry about it until my R2 is allowed to pull the full 630-650 amps at any charger in the US. At this point that is not happening.

 

[Ralph]

Is there additional cost to infrastructure to support a lot of 800v vehicles at a given site? Not when retrofitting, but on a new install?

 

[mkhuffman]

Is there additional cost to infrastructure to support a lot of 800v vehicles at a given site? Not when retrofitting, but on a new install?

800V isn't the issue. It's the power. 500 Amps x 800 Volts is 400 kW. If you have 10 vehicles pulling 400 kW, you need massive infrastructure providing that power. The power company charges MORE for that kind of high power. That is one reason DCFC is more expensive than home charging. The surcharges for massive power draws can be significant.

The short answer to your question is "yes".

 

[mkhuffman]

My buddy worked for them as an engineer back in the day and he was working on the 800v pack at the time.

The estimate of when it comes is my guess.

My guess is it will come in the next major refresh. Rivian seems to be on a three year cycle. If that holds, the next major refresh will be introduced sometime next year as a 2028 model year truck. I am hoping for 800V and 180 kWh. That would be my dream R1T.

It would have the range and capabilities that really don't get much better with solid state. IMO, anyway. Sure a 30 minute 800V charge is not as good as a 10 minute 1000V solid state battery charge, but really I am used to the 30 minute waits.

It takes 41 minutes in my R1T to go from 10 to 80%. To me that is acceptable. Shaving it to 30 would be great, but not life changing. Shaving it to 10 minutes would put it almost on parity with gas powered vehicles. But I cannot see how the infrastructure will be ready to support that kind of massive power draw within the next 10-20 years.

Seriously. Here is the math.

180 kWh x 0.7 = 126 kWh. Adding 126 kWh in 10 minutes requires an average power of 756 kW. Average. Not peak. Insane. We won't see chargers with that kind of capability for 10 or 20 years. In the meantime, I can love my 126 kWh 30 minute charges all day long.

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