2022 R1T Quad Motor Battery Degradation Estimate at 54,000 miles (~4% degradation)

[Budman]

This is a follow-up to a post I did in May of 2024 when my R1T had 42,000 miles on it.

https://www.rivianforums.com/forum/...dation-2022-r1t-quad-motor.27821/#post-538633

I now have 54,000 miles on the R1T and I repeated the test using the same procedure;

1. Fill battery to 100%
2. Drive on a mix of rural roads at 55 - 60 mph and Interstate at 70 to 75 mph
3. Record the energy used and miles driven at each 5% of battery state of charge increment as reported on the main UI screen in the vehicle
4. Stop test at 9% state of charge. Then extrapolate results to 0% state of charge
5. Fill battery from 9% to 100% and record energy put into the battery. Then extrapolate the results to estimate energy needed to go from 0% to 100%.

This gives two estimates of the 100% capacity of the battery. One estimates how much was used, the other estimates how. much put back in. I did not want to drain my battery to 0% so I'm doing linear extrapolations to the full battery estimate. The results are very linear from 100% to 10% but the behavior COULD be non-linear in the last 10% so this is just an estimate of the true capacity.

Estimate 1: Energy used while driving from 100% state of charge to 10% state of charge.

Data taken at every 5% SOC. Full capacity of battery is estimated by where the linear fit to the data crosses the 0% SOC mark.

At 42,000 miles: ~3.9% degradation
At 54,000 miles ~4.8% degradation
assuming the original capacity was 131 kWh as reported elsewhere

The Rivian warranty covers the battery to 70% of original capacity at 150,000 miles (30% degradation)


Estimate 2: Energy put back into battery to go from 9% to 100%. The battery reading when I stopped the test both times was 9% so I had to put 91% back in..

Using this method the degradation estimates are.

At 42,000 miles: ~2.1% degradation
At 54,000 miles ~3.9% degradation


BATTERY DEGRADATION ESTIMATES;

For reference, here is the chart shown miles driven during the test and the estimated full pack range. This is for reference only, environmental conditions, traffic, driving speeds were not the same between the two test so don't read too much into the differences between them. But, ~315 miles of full pack range was seen each time and this agreed very closely with the range estimate given by the vehicle when I started driving at 100% state of charge. This was on a mix of 60 mph and 70 mph speed limit roads.

Sponsored

 

[mudito]

Amazing experiment. Thanks for sharing!

 

[JWortman]

The data provided by logging into your Rivian account in A Better Route Planner shows the actual remaining capacity of your battery accounting for degradation. I’d be curious to see how that data compares for your vehicle against what you found out through your testing. Really cool experiment!

 

[Budman]

The data provided by logging into your Rivian account in A Better Route Planner shows the actual remaining capacity of your battery accounting for degradation. I’d be curious to see how that data compares for your vehicle against what you found out through your testing. Really cool experiment!

ABRP shows a battery capacity of over 130 kWH. Pretty sure the capacity estimate is too high.

 

[JWortman]

ABRP shows a battery capacity of over 130 kWH. Pretty sure the capacity estimate is too high.

Good to know, thanks!

 

[Yossarian]

In spite of possible uncertainty, I very much appreciate information. It is however both good news and bad news. It's good news for Rivian owners who now are likely looking at very robust battery life, likely substantially exceeding estimates. The bad news is this is actually not usual, and has the effect of delaying battery pack recycling at scale.

As I understand it, one major roadblock to large scale EV battery pack recycling is a lack of raw material, that is spent battery packs. This makes investing in large-scale recycling tougher, since battery packs are lasting much longer than expected, and subsequently, there is a lack of raw material to recycle. Consequently, few want want to invest in recycling at this stage because of the apparently long battery pack life and the uncertainty involved.

 

[MannyMan]

So the large pack has a 135kWh physical capacity with a useable 131kWh capacity?
I thought it was 135kWh useable.

 

[shrink]

So the large pack has a 135kWh physical capacity with a useable 131kWh capacity?
I thought it was 135kWh useable.

https://rivian.com/support/article/what-is-the-usable-kwh-capacity-of-your-battery-packs

 

[mkhuffman]

Based on what I have seen with my Mach-e, 5% at 50k+ miles is really good. In my experience, the degradation is more rapid initially and then slows down as the car ages. My Mach-e has 48k miles and 9% capacity loss.

IMO some people will have less than 5% loss, but a higher percentage will have more. I think 8-10% loss at 50k is typical. Again, IMO. It would be great for others to do a similar test to see what they have. My BMS reports State of Health, so it is easy to see what mine is. Too bad SoH isn't reported via the Rivian API.

 

[Luvolbikes]

So if you repeat your test at 66k miles will we have 3 points needed to see if degradation is linear or Infering a nonlinear curve? At a percentage of remaing total or at a steady rate of decline?

 

[UnsungZero_OldTimeAdMan]

So under 10% by 100k miles. Not bad at all. What are your usual charging habits? lower and upper SOC limits?

 

[VSG]

So if you repeat your test at 66k miles will we have 3 points needed to see if degradation is linear or Infering a nonlinear curve? At a percentage of remaing total or at a steady rate of decline?

With 3 points you could fit it to almost ANY function. https://en.wikipedia.org/wiki/Von_Neumann's_elephant

The right way to do it would be to use the functional form of a measured, known degradation curve for this chemistry. Or at least the functional form of the theoretical curve. And if that isn't know, a linear fit is still probably the least speculative way to fit the data.

 

[Budman]

So under 10% by 100k miles. Not bad at all. What are your usual charging habits? lower and upper SOC limits?

I mostly charge at home to 70% and typically it does not get below 40%. seldom has it dropped under 15%.

DC fast charged maybe 40 times on road trips.

Very little exposure to hot weather (live in Minnesota, truck in a garage during the heat of the day most often)

 

[Budman]

So if you repeat your test at 66k miles will we have 3 points needed to see if degradation is linear or Infering a nonlinear curve? At a percentage of remaing total or at a steady rate of decline?

Sadly, or actually it’s happily, I won’t be able to repeat at 66k. I’m trading in this Gen 1 R1T for a Gen 2 R1T max pack in a few days.
Why? My Gen 1 has been awesome. It was inevitable I would replace it with another someday. With the recent trade in offer I figured this was as good a time as any.

And, the new one will give me a great opportunity to test the efficiency of the Gen 2 dual motor with the Rivian motors vs the really early Gen 1 Quad with Bosch motors.

 

[SeaGeo]

ABRP shows a battery capacity of over 130 kWH. Pretty sure the capacity estimate is too high.

Yeah, that's what the BMS reports. It's a little curious that the BMS fluctuates but doesn't seem to reflect the degradation you'd expect.

The right way to do it would be to use the functional form of a measured, known degradation curve for this chemistry. Or at least the functional form of the theoretical curve

Now you're speaking my language.

Sponsored