Rivian R1T charging curve test 20-80% [by TFL]

[mkennedy1996]

You made my day.

my 1.5 cents: charging to 80% is not the way to do it, especially on road trips. 15-65% is your target.

Here is my experience in charging my 5 Teslas. We have over 150,000 miles of EV experience with close 500 DCFC sessions. We do simple math every charge session on road trips.

We never want to go below 50 miles of range (comfort zone and battery health). [base]

After we plug in, we route to the next charger to see the distance. [distance]

We monitor our energy consumption vs the rated range for the current conditions. This is usually pretty consistent at about 30% more energy used than the rated spec. [range correction]. When we tow, or it is really cold, we recalculate.

Formula: [base] + ([distance] * [range correction]) = Rated Range to Charge to before departing

Se, if we need to go 132 miles, we would charge to 132 * 1.3 + 50 = 221 miles of rated range needed to depart.

This has never failed us and we stay low in the charge curve.

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[SeaGeo]

20 minutes is perfect. Goal for me is 20-30 minutes approximately every 2.5 hours to let the family take a break. I learned that was the ideal interval on our trip to Yellowstone last summer.

My routes I use for backstopping are:

-Seattle to Mazama/Winthrop (winter conditions, southern I-90 route)
-Seattle to Missoula
-Seattle to Leavenworth round trip

These are the routes we most routinely do in a single day. Any longer trip is multiple days, so comparing these to my ICE itinerary gave me a lot of confidence that road tripping in an EV would be comfortable provided it had close to 300 mi range.

That Leavenworth EA spot is clutch!

I've been looking at the route Glacier, and apparently the drive to Whitehorse is pretty easy per one of the local owners.

 

[Forager]

Yeah, the EA charger in Leavenworth is a great location, without it most of our adventures couldn’t happen or would be overnight. I’m glad RAN has several planned chargers along Highway 97, it will open up possibilities for trips in north-central and NE Washington that are off limits right now.

They’ll have RAN up to Whitehorse? That’s going on the bucket list!

 

[SeaGeo]

Yeah, the EA charger in Leavenworth is a great location, without it most of our adventures couldn’t happen or would be overnight. I’m glad RAN has several planned chargers along Highway 97, it will open up possibilities for trips in north-central and NE Washington that are off limits right now.

They’ll have RAN up to Whitehorse? That’s going on the bucket list!

Not sure about RAN up there. There's an EA in Kellogg and chargepoint in Whitehorse. ABRP will say the drive between the two can be a push, but it's apparently pretty easy.

 

[ajdelange]

Hey @TFLtommy, could the 150kW peak be due to the 400V pack? 350kW is only possible at 800V charging.

Time to post the HPC350 envelope again:

As the chart shows 350 kW charging requires a minimum of 700V (because the charger can supply at most 500A).

Those EA chargers could have been current limited...

More probably power limited for a variety of reasons.

 

[ajdelange]

Lotta weirdos out there never using 40% of their battery in the name of protecting 10% of the theoretical capacity

Yes. They tend to be the technical types who have a better understanding of how these things work than the average guy. Of course when they need to use the top or bottom 20% they do. They just avoid doing that where possible understanding the potential benefits.

So, of course, we have to ask: "What's the cost of not using that 40%?"

 

[ajdelange]

...both Model S Plaid and R1T use a peak 450V pack and would be around 430V at 50% hitting ~150kW as both demonstrated with a 350A limit.

A Tesla V3 charger is capable of 600 A and delivers 250 kW meaning its terminal voltage is 417 V

 

[Max]

As the chart shows 350 kW charging requires a minimum of 700V (because the charger can supply at most 500A).

This tells me that there won’t be too many BEV trucks in future that are not 800+ volt when charging. Does charging at 300kW at 800V generate more heat in the battery than 150kW at 400V? Or heat is just a function of current?

Is it safe to assume any 350KW Charger is capable of charging at 800V?

@TFLtommy can you see battery temperature anywhere in display?

 

[ajdelange]

At very best, the R1T and R1S could charge at a peak of 220kW (440V x 500A).

Granted that's 1.63C and it might not be prudent to charge at even that rate for prolonged periods by why not apply enough voltage to get up to 250 kW (1.85C)? Tesla does that on its 385V batteries. The reasons are, of course, that 1.85C may be pushing it and that I^2R losses in the pack itself would go up requiring more cooling.

Even if could sustain an average of 175 kw from 10-80, that's still 30 minutes to get 210-220 miles of range.

That's the reality of charging a BEV at 1.3C. I'm fine with that.

My point is, on an 800V architecture, you could peak at 350kW (theoretically) and likely average something more like 270kw from 10-80.

Yes but that's 2.6C peak and 2C average. Not saying that some day we won't have batteries that can sustain that rate but today we seem to be closer to 1C than 2C.

Now you're down under 20 minutes. That's a BIG difference if you have to do it 2-3 times along a journey.

That's a 10 minute difference per stop. Three stops, 1/2 hour. Everyone's perception of BIG is different, I suppose.

And it's more in line with what drivers of modern Teslas and Hyundais are used to (due to efficiency and charging speed, respectively).

You'll just never be able to get reasonable range replenishment in under 30 minutes on the 400V architecture, not in a vehicle getting 2-2.5 miles/kW-hr.

It doesn't matter what the voltage of the system is first order. What matters is the charge rate. If you are doing 1C it's going to take you 36 minutes to pick up 60% of the rated range. If you are doing 2C, whether you got it by cramming in huge current in a 400V system or half that (approximately) in an 800V system, it will take you 18 minutes. The question is as to whether the battery can stand 2C.

The advantages in the higher voltage systems come in copper savings in both the charger and vehicle - not in charging speed.

 

[ajdelange]

I’ve never owned an EV or charged one before, so I’m interested an explaination of why EA dispensed (and charged) 86 kWh of power while the Rivian only registered around 74 kWh. I understand transmission and conversion losses, but I would have expected transmission losses to be accounted for in the price per kWh put into the vehicle. This represents 15% loss, and I would have expected very minimal losses when the power source is DC, running through a short cord, and being delivered into DC battery (no conversion loss like you have at home when using AC power).

Something is bigtime wrong if 15% loss is incurred in a DC fast charging system. It was suggested in another post that there is a problem with the Rivian software. Seems this might be the case.

 

[Rivian_Hugh_III]

.
I can hear her already: “Why did you pay $80K for this if we have to take my car?"

Well, let’s see. The Rivian is

• Better for the environment
• Better visibility
• Better storage
• Better power
• Better traction
• Better seats
• Better interior
• Better aerodynamics
• Better flexibility for on-road/off-road
• Better cost per mile

But take the outback if you prefer!

 

[ajdelange]

Formula: [base] + ([distance] * [range correction]) = Rated Range to Charge to before departing

It's really exquisitly simple. Take the rated miles for your vehicle (314) and divide by 100 (3.14). That's the rated miles per percent of battery. Take the reciprocal of that (1/.314 = .32). Memorize that number (or write it on a sticky and put that in your truck). When at a charging station find out how many miles to the next one and multiply by that number e.g. 132 miles --> .3*132 + .02*132 =39.6 + 2.64 = 42%. That's how much charge you need to add. Note that in this case you can neglect the .02 and just rough it at .3*132 = 39.4 and then toss in a couple of extra percent. You would also toss in an extra couple of percent if you know the stretch or road you will be driving demands consumption a couple more percent that normal (because it's wet or there is a head wind or its uphill or you know this bit of road). Or just add 10% for "margin". Add 50% to your battery and go on your way.

I've posted this many times before elsewhere and often get responses such as "You call that simple?" I am aware that a frightening number of people are innumerate. This won't appeal to them.

 

[ajdelange]

This tells me that there won’t be too many BEV trucks in future that are not 800+ volt when charging.

I'm not so sure about that. 800V architecture saves copper but bring in a whole new can of worms in insulation and safety requirements. These can be managed (Lucid and I think the Hummer at least have 800V).

Does charging at 300kW at 800V generate more heat in the battery than 150kW at 400V? Or heat is just a function of current?

Higher voltage means less current for the same power and thus less heat.

Is it safe to assume any 30KW Charger is capable of charging at 800V?

Is that a typo i.e. do you mean 300 kW? I'll assume you mean 300. Look at the CHARIN envelope a couple of posts back. The 350 kW locus is the hyperbola that chops off the upper right hand corner. The 300 kW locus is another hyperbola parallel to the one shown but it starts at 600V x 500A. A charger is whatever it is so all I can say on this is that if it meets HPC350 then it will have the envelope given in the other post and will, thus be capable of any voltage between 200 and 920.

 

[branden]

A Tesla V3 charger is capable of 600 A and delivers 250 kW meaning its terminal voltage is 417 V

That's not relevant for comparing to an EA station

 

[branden]

Yes. They tend to be the technical types who have a better understanding of how these things work than the average guy. Of course when they need to use the top or bottom 20% they do. They just avoid doing that where possible understanding the potential benefits.

So, of course, we have to ask: "What's the cost of not using that 40%?"

What's the cost? Almost nothing. Use the battery.

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