Battery capacity questions

[impulsoren]

I have generally heeded the “don’t fret about it it’s not as meaningful as you think” advice regarding displayed battery capacity from Rivian Roamer. My displayed capacity has always seemed to be on the low end but the car works fine.
I just looked and this is what I saw:

The only reason I think this is worth my time posting here is because it’s outside the bulk of other vehicles’ data. What is up with the decline starting this last spring?
An artifact of something? Charging habits are the standard ~20-70% on L2, up to 100% a couple times a month, DCFC once or twice every couple months.
An interesting note there was an update around May that gave me regular “regen limited” warnings in conditions it had never before occurred, then the warnings just went away after a few weeks. Related? This is all nothing?

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[MountainBikeDude]

I have generally heeded the “don’t fret about it it’s not as meaningful as you think” advice regarding displayed battery capacity from Rivian Roamer. My displayed capacity has always seemed to be on the low end but the car works fine.
I just looked and this is what I saw:

The only reason I think this is worth my time posting here is because it’s outside the bulk of other vehicles’ data. What is up with the decline starting this last spring?
An artifact of something? Charging habits are the standard ~20-70% on L2, up to 100% a couple times a month, DCFC once or twice every couple months.
An interesting note there was an update around May that gave me regular “regen limited” warnings in conditions it had never before occurred, then the warnings just went away after a few weeks. Related? This is all nothing?

Lots of little factors, typically your capacity will fluctuate between summer and winter.

Edit * what's your current mileage? Are you the original owner?

Just for comparison sake, '23 R1T 75,000kms data was originally tracked via Electrifi, and added to Rivian Roamer.

 

[mkhuffman]

It is good you are doing some charges to 100% a couple of times a month. Are you also running it down to around 10% sometimes? The best way to calibrate the BMS, is to run it down to 10%, charge it to 100%, and then run it back down to 10% again. That gives the BMS a complete cycle of the max and min points of the battery.

IMO that type of slide in capacity is a little concerning especially since it is happening in the middle of summer (I have seen a slide in the cold months). If I were you, I would definitely try the recalibration procedure a couple of times and see if that helps. If it does not, it may mean your battery is doing what these batteries typically do.

My Mach-e was at 89% State of Health (SoH) after three years. It was pretty frustrating, but sometimes that is just what happens. I suspect all the WOTs I did in that car degraded the battery, but it is just a guess. Some people claim WOTs won't cause any issues. I have my doubts. I did run it down to 0-3% a few times, which also could have hurt.

 

[impulsoren]

I almost never get below 20%, only to 5% a couple times, I live far enough out it will require careful planning to avoid stranding myself.
I have no idea what the original owner did. I have put 30,000 out of 55,000 on it.
I do flog it but can’t imagine that’s a problem.
interestingly but maybe not, estimated mileage has always showed 314 at 100% in conserve but I haven’t kept track of how much I actually get because it’s never really that much.

 

[VSG]

Plotting it as a zero-suppressed graph exaggerates the change. 123.5/125.5 is only like a 1.5% drop in efficiency over that time. While not nothing, it's also not really significant unless it keeps going down uniformly.

Gen 1 vehicles have an 8 year/175,000 mile battery warranty, so if your pack really is going downhill you have plenty of time.

Regardless, since you said you bought it used and have 55k miles, I strongly suggest you take it to a service center and pay for the comprehensive inspection before your 60k warranty on other parts comes up. This will certainly save you thousands of dollars on future repair costs.

 

[impulsoren]

With the number of times I have been in for little things already I bought an extended service plan that they call a “warranty”. The xcare discussed here at length last year. I don’t think either Rivian or xcare will replace the battery until it’s super bad.
I still am not excessively worried about battery capacity, even at 250 miles of range I would rarely have to charge away from home. I did spend my car budget for the next 30 years on this vehicle though so that’s why I am thinking about this more than I probably should. (Although I suspect I will figure out a funding source for r3x if that happens.)
I guess my intent with posting here is to verify that this curve actually is an unusual occurrence and hoping someone would chime in with “yeah they often do that then when xx happens it goes away”. Also what will happen to the fuel gauge display as it degrades will it continue to show a predicted 205 miles at 70% or will it display 205 miles at 80%?

 

[KBabione]

For some bizarre reason, I didn't sign up for Rivian Roamer until this month (even though we've had our R1S for 3 years), but I'm seeing the same trend...Since I signed up my battery capacity is down .8 kWh this month alone!

I'll definitely be keeping an eye on it - thanks for making me look!

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