Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health

[clerks]

So 74.5?

Percentage is 79.

 

[AlanSubie4Life]

Percentage is 79.

Yeah about 75kWh. So perhaps 7% capacity loss depending on where you started.

If this happened suddenly there is a chance it is just a glitch and it may recover somewhat. We’ve seen that.

Hard to know how you will fare long term, but capacity loss will slow. I’d guess 10-15% (total) in another 2 years. And then fairly flat from there for a while. As I said, expectations depend on where you actually started.

 

[Jejunjm]

Inspite of charging to 79.5 my NFP still is listed at 79.1.
How is this number calculated or measured?

 

[AlanSubie4Life]

Inspite of charging to 79.5 my NFP still is listed at 79.1.
How is this number calculated or measured?

I don’t know exactly. I think we can say NFP is more a projection/estimate of what you would have at 100%, while the nominal remaining is what the BMS actually guessed/measured in a particular charging event. NFP adjusts over time in response to various charging events, it seems.

 

[AAKEE]

Yeah about 75kWh. So perhaps 7% capacity loss depending on where you started.

If this happened suddenly there is a chance it is just a glitch and it may recover somewhat. We’ve seen that.

Hard to know how you will fare long term, but capacity loss will slow. I’d guess 10-15% (total) in another 2 years. And then fairly flat from there for a while. As I said, expectations depend on where you actually started.

From my information from research posted a few days back, we know that high SOC and high temps will cause the calendar aging to continue, and to level out much later.
The calendar aging shows a square root behaviour, so it lessens with time but do not stop. A small degradation value will look like a straight (linear) line earlier than a high degradation will do.
Because of this, my babied battery at low temps most of the year will seem to degrade linear almost from the start but a battery always sitting at 90% SOC at high temps will go down during a longer time, and when it will hit a low sloping (”linear”) line it will have lost a lot more than my battery have.
Down below, low SOC to the left, high to the right.

Compare my low SOC at some 15C average with a battery to the right at 25C average.
The square root behaviour make it dive hard for long time.

I did grab the Model 3 P 2021 dara from both teslafi and teslalogger.

We can see that at teslafi does the range level out at about 15000km, with some 485 km range. My range is way higher, and as there is a limited number of cars(some 10 doen to o ly a few at my ODO-reading), my values draw the average upwards. Without my car the mine would dive a bit faster.
Teslafi doesnt show the spread, only the average is shown which of course can be stressful for a guy below avg.

Teslalogger show all measuring points.
The average line hit 470km at about 25000 to 30000km. There is quite a few measuring points down to 460km with low ODO readings so @clerks is not alone.

The 2170L-cell is supposed to be a low cobalt battery. We know Tesla advertised it as this but not the number of how low.
Cobalt is amoung other things the stabilizer of the chemistry and the problem historically have been to keep the longevity with less cobalt. Tesla/Panasonic has probably solved this somehow but for me it felt safe to let my batterys life begin on the safe side.

 

[AAKEE]

I could add, that by now members that did read my recebt posts know that time is/can be much worse then miles.
For @clerks this means that you could compare your ar with others, with the same age more or less regardless of the miles.
Miles/cycles have some impact but less than time, specially at high SOC.
Theres cars on the average line with the same age having the same range as @clerks.

 

[AlanSubie4Life]

I could add, that by now members that did read my recebt posts know that time is/can be much worse then miles.
For @clerks this means that you could compare your ar with others, with the same age more or less regardless of the miles.
Miles/cycles have some impact but less than time, specially at high SOC.
Theres cars on the average line with the same age having the same range as @clerks.

I guess at this point we're getting a pretty good idea of whether the new 2170L have better capacity loss characteristics than the prior 2170. Looks to me like it's probably not much different - 6-10% or so after a year looks like it should be expected.

that time is/can be much worse then miles.

Maybe I'm missing something, but it's unfortunate that you can't plot range by vehicle age in TeslaFi, instead of vs. mileage. I guess it's harder for TeslaFi to determine the build date and have that data be "clean."

 

[AAKEE]

Maybe I'm missing something, but it's unfortunate that you can't plot range by vehicle age in TeslaFi, instead of vs. mileage. I guess it's harder for TeslaFi to determine the build date and have that data be "clean."

Yes, thats right: no you can not.

Both the age issue, but mostly I’d say that people do not really know about calendar aging. If most people think miles is the only important factor thats what they want to see, and thats what the teslafi will show. Theres a high probability that the teslafi guys also do not know that much about calendar aging.

I guess that in the most cases the batteries behave like in the research reports. = We can predict how the battery will degrade from ”onest” data.
In the opposite way, but from same data, as calendar aging is the dominant degradation in the early battery life, we also could have the table sorted as per your idea with age instead of miles. If the average resting SOC was marked with colors we would have different lines for different average SOC as per the calendar aging grapghs in my earlier posts. There would be minor variances caused by the different ODO-readings.

 

[AlanSubie4Life]

Yes, thats right: no you can not.

Both the age issue, but mostly I’d say that people do not really know about calendar aging. If most people think miles is the only important factor thats what they want to see, and thats what the teslafi will show. Theres a high probability that the teslafi guys also do not know that much about calendar aging.

I guess that in the most cases the batteries behave like in the research reports. = We can predict how the battery will degrade from ”onest” data.
In the opposite way, but from same data, as calendar aging is the dominant degradation in the early battery life, we also could have the table sorted as per your idea with age instead of miles. If the average resting SOC was marked with colors we would have different lines for different average SOC as per the calendar aging grapghs in my earlier posts. There would be minor variances caused by the different ODO-readings.

You should email the TeslaFi guys, haha. I bet they could go through their data and get reasonable info on average SOC/storage SOC for each subscribed vehicle. And they could probably start gathering (approximate) build date info from customers (this seems more difficult if they haven't already been gathering it - but they could probably do it formulaically and get pretty close in many cases - just look at initial vehicle mileage, join date, and the average rate it was adding miles for the 3-6 months after join date, and then back-extrapolate to the approximate "in-service" date - obviously this would fail sometimes due to varying driving patterns, vehicles that have a long build to in-service delay, etc.).

Then they could generate all the awesome plots!

If the average resting SOC was marked with colors we would have different lines for different average SOC as per the calendar aging grapghs in my earlier posts. There would be minor variances caused by the different ODO-readings.

They could even have a (very sparse) 3D plot of capacity loss vs. age and mileage!

 

[clerks]

I could add, that by now members that did read my recebt posts know that time is/can be much worse then miles.
For @clerks this means that you could compare your ar with others, with the same age more or less regardless of the miles.
Miles/cycles have some impact but less than time, specially at high SOC.
Theres cars on the average line with the same age having the same range as @clerks.

I'm not seeing a lot of cars with 10k km with my range. I do see some. My assumption is most of them with that low mileage are probably newer than mine. My commute is about 30 miles round trip. I guess I'll start charging to 75 just before departure which will keep me between 60 and 75. Does that sound like a reasonable compromise? Or should I be aiming lower?

 

[kailm]

My S has half the degradation and double the miles of my 3. I like the Panasonic 18650's better than the 2170's. 2170 was all the rage, but no numbers to back it up. Now it is starting to show.

The button just dragged everyone back in like a hook with a worm on it that a bass couldn't resist.

Its a numbers game. More cells mean a dead cell counts less towards degradation. Wait till the 4680s have a dead cell. It will have a massive drop in range. Hence 18650 is better, but more expensive.

 

[kailm]

This has been bothering me. If the threshold for warranty is 70 percent, what's the point of tesla giving me a new pack at 70 percent? How does that help someone and how much money could tesla actually save versus a new pack? Strikes me as really unfair.

If you hit 69%, they give you a pack 75% just so they dont have to swap it out in a few days. You dont get another 100% pack.

 

[clerks]

If you hit 69%, they give you a pack 75% just so they dont have to swap it out in a few days. You dont get another 100% pack.

What's the point of giving me a 75 pack if I hit 69? So stupid. Don't bother.

 

[jjrandorin]

If you hit 69%, they give you a pack 75% just so they dont have to swap it out in a few days. You dont get another 100% pack.

I havent combed through the warranty, but its either "the warranty is fulfilled" when they replace the pack and the refurb is under the same warranty as other replacement parts (something like 12 months 12k miles or something), OR you would get "the balance" of whatever is left on your original warranty.
There is almost no chance the "warranty" starts over, unless someone was buying a new pack themselves.

I havent looked through it, but this is likely the case as it would be with replacing a motor in an ICE.

 

[stopcrazypp]

What's the point of giving me a 75 pack if I hit 69? So stupid. Don't bother.

So that you get above 70% at the time the warranty ends. That's all Tesla is guaranteeing, nothing beyond that.
Also avoids people trying to run their battery down on purpose if they get close, to gamble on getting a completely new pack.

 

[Jejunjm]

So that you get above 70% at the time the warranty ends. That's all Tesla is guaranteeing, nothing beyond that.

I suspect it won't be quite that bad. They need to factor in the cost of labor and the math/worry that the refurbished part fails. Refurbished parts should carry there own warranty as well....

 

[stopcrazypp]

I suspect it won't be quite that bad. They need to factor in the cost of labor and the math/worry that the refurbished part fails. Refurbished parts should carry there own warranty as well....

This is the replacement pack warranty:

• Vehicle High Voltage Battery*: 4 years or 50,000 miles, whichever comes first

Then there's also this:

Any Parts or Used Parts repaired or replaced under this Tesla Parts, Body & Paint Repair Limited Warranty continue to be covered by the applicable original warranty period of the repaired or replaced Part or Used Part (mentioned above in "Coverage Period") or for a period of 90 days, whichever is longer.

Vehicle Warranty

Basically the max you get is that 4 years / 50k miles or if your remaining original warranty is longer, the remaining balance. I should note also the warranty on the replacement pack does not appear to warrant for retention, so presumably the time period is still the same as your original (so you don't get an "extension" for retention, only for complete failure).

So perhaps it might not be a 75% pack, but it definitely won't be a brand new pack, as they don't need to give a brand new pack to ensure it remains above 70%, unless you are talking about a car that was essentially brand new when it fell below 70%. Logically they would give you a refurb pack with roughly the same age/mileage and it'll natural work out.

 

[MP3Mike]

This is the replacement pack warranty:

Then there's also this:

Vehicle Warranty

Basically the max you get is that 4 years / 50k miles or if your remaining original warranty is longer, the remaining balance. I should note also the warranty on the replacement pack does not appear to warrant for retention, so presumably the time period is still the same as your original (so you don't get an "extension" for retention, only for complete failure).

So perhaps it might not be a 75% pack, but it definitely won't be a brand new pack, as they don't need to give a brand new pack to ensure it remains above 70%, unless you are talking about a car that was essentially brand new when it fell below 70%.

No. If your battery is replaced under warranty you get the remaining time on the warranty the battery was replaced under. If your warranty expires the day after the replacement, then your warranty is gone 1 day later. (Some manufacturers offer a minimum 30 or 90 day warranty on end-of-warranty repairs, Tesla doesn't.)

If you buy a replacement HV pack you get a 4 year/50k mile warranty on it.

 

[stopcrazypp]

No. If your battery is replaced under warranty you get the remaining time on the warranty the battery was replaced under. If your warranty expires the day after the replacement, then your warranty is gone 1 day later. (Some manufacturers offer a minimum 30 or 90 day warranty on end-of-warranty repairs, Tesla doesn't.)

If you buy a replacement HV pack you get a 4 year/50k mile warranty on it.

You may be right, that part does say "purchase". They have a separate section for parts replaced under the original car warranty:

Parts repaired or replaced, including replacement of the vehicle, under this New Vehicle Limited Warranty are covered only until the applicable warranty period of this New Vehicle Limited Warranty ends, or as otherwise provided by applicable law.

They actually clarify what is the expected condition of the replacement pack under warranty:

If your Battery or Drive Unit requires warranty repair, Tesla will repair the unit, or replace it with a new, reconditioned or re-manufactured part at the sole discretion of Tesla. The warranty replacement may not restore the vehicle to a "like new" condition, but when replacing a Battery, Tesla will ensure that the energy capacity of the replacement Battery is at least equal to that of the original Battery before the failure occurred while taking into consideration other factors, including the age and mileage of the vehicle.

https://www.tesla.com/sites/default/files/downloads/tesla-new-vehicle-limited-warranty-en-us.pdf

Basically they'll give you a pack in a condition expected of the age/mileage of the vehicle at the time.

 

[MaxRSM]

In Europe the warranty is 8 years 160'000 km on model 3 Sr+ and 192000 km on LR e performance, with a threshold of 70% of the capacity when brand new.

i doubt Tesla has so much packs with 75% capacity laying around.
Maybe they have some cars that are so bad built that they need to swap the car with a new one to the customer and they need to scrap the bad one and probably they remove the battery to recoup some money.
But i doubt that those batteries have lot of wear.