Battery capacity loss question

[modlyowner]

I have a 2021 MY delivered Dec 2020 with about 23K miles on it. I would note that because I live in a city, the car has been charged almost exclusively at Tesla Superchargers.

I know there are many threads on "expected" and "normal" capacity loss (even though Tesla does not mention this unless you are talking to their service department AFTER you have purchased a car). The typical loss mentioned seems to be 3-5% in the first year, and then maybe 1-2% in subsequent years.

I first became interested in this as I noticed at 100% charge my car recently shows a range of under 300mi (assumes 250wh/mi) whereas last year I recall this being in the 315-320mi range when I charged. (I typically look at battery percentage and not estimated range, so I have no idea when this number actually started to decrease).

At 16 months of age and 23k mi, TeslaFi and Recurrent are telling me my battery has lost about 9% of its rated capacity, which is even outside the "expected" range. This lines up with what the car is telling me in the UI.

I have taken this up with Tesla support, who have run diagnostics on my battery. They will only tell me I have "some capacity loss, but within the normal range". They will not provide me any detailed data from what they are seeing on their end.

I have a few questions for others on this board:
1. It is normal for Tesla to not share their diagnostic results? I am concerned because third party apps like Recurrent are definitely telling my the capacity has decreased well beyond what is normal in the first 1-2 years.

2. Has anybody else experienced capacity loss at this scale under these conditions? How did you deal with it? Was a battery replacement or other remedy possible even though this hasn't triggered the 70% level in the warranty?

3. I have seen many threads parroting the comment from Tesla support that 3-5% range loss in year one of ownership is "normal". However, I cannot find any marketing material, disclaimers, whitepapers, etc. from Tesla supporting this assertion. I am trying to determine where I could have gotten this info from Tesla (not from a message board) before purchase. In fact, the only official statement on battery capacity I have been able to find from Tesla is that the battery should retain 90% of capacity by 200k miles (Tesla: Battery Capacity Retention Averages 90% After 200,000 Miles). This is obviously very different than what I have been told by Tesla support and the common knowledge on this board.

 

[jjrandorin]

which is even outside the "expected" range.

No, it isnt. Not sure where you got your "expected range of 3-5% first year" but thats not what I have seen from the 100s of threads on this topic.

No, you would not have gotten anything from tesla stating any amount of "normal" loss, all you would likely have is a statement that batteries degrade over time and that the warranty is for 70% at 8 years or 120k miles.

That last statement is "model S and X" data, which is not the same battery as model 3 / Y.

I will point you back to the warranty they offer, which is the only official statement "70% capacity over 8 years or 120k miles" for a AWD model Y. Your capacity loss is normal, there is nothing I have read on all of these threads for model 3 / Y that says "3-5% 1st year.

I doubt you will find anything that says that with in the 226 page (not post, page) thread we have on this topic in the model 3 subforum either:

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

i bought my model 3 in aug 2018. After the software upgrade I only got 316 miles when charged to 100%. Last night I got only 312 miles from 5% SOC to 100%. A 4% degradation within 10 months? Have others degraded similarly?

teslamotorsclub.com

TL ; DR -- up to 10% is "normal" the first year. Calendar aging has the most to do with capacity loss, for more detail and data, search the thread above for posts from @AlanSubie4Life and @AAKEE

 

[modlyowner]

@jjrandorin This is why I specifically posed the question as to what TESLA has said with regards to this issue.

That 3-5% number (with 1-2% thereafter) is a direct quote from my service technician from last month. It also lines up with what has been widely posted on this forum.

I don't recall many anecdotes highlighting how 10% loss is normal, but if you want to DM me some of those posts I'm happy to take a look.

Your response doesn't address any of my specific questions on this issue. I know this isn't a new topic but I haven't been able to find answers to those anywhere on this forum.

 

[jjrandorin]

1. . It is normal for Tesla to not share their diagnostic results? I am concerned because third party apps like Recurrent are definitely telling my the capacity has decreased well beyond what is normal in the first 1-2 years.

Yes, it is normal for tesla not to share any of their internal data. You also have not experienced capacity loss that is abnormal. I am not going to search out specific posts, but that 226 page thread has several (likely dozens to multiple dozens) of posts on exactly that discussion that will show that this is fairly normal.

2. Has anybody else experienced capacity loss at this scale under these conditions? How did you deal with it? Was a battery replacement or other remedy possible even though this hasn't triggered the 70% level in the warranty?

Yes, multiple dozens of reports in the thread I linked you to above. I would say "hundreds" but I havent counted, but feel comfortable stating multiple dozens, enough to say that "3-5% first year for model 3 / Y would be low, not "average". No, tesla will not do anything at all unless it triggers the warranty (nothing, they wont even talk to you other than to try to poorly explain "its normal" or spout off some nonsense.

3. I have seen many threads parroting the comment from Tesla support that 3-5% range loss in year one of ownership is "normal". However, I cannot find any marketing material, disclaimers, whitepapers, etc. from Tesla supporting this assertion. I am trying to determine where I could have gotten this info from Tesla (not from a message board) before purchase.

If you got anything at all from tesla "before purchase" it would have been verbally. There is no information from tesla that states "3-5% for model 3 / Y is average, either from tesla, or not.

 

[AlanSubie4Life]

At 16 months of age and 23k mi, TeslaFi and Recurrent are telling me my battery has lost about 9% of its rated capacity, which is even outside the "expected" range. This lines up with what the car is telling me in the UI.

Completely normal. And looking at miles in this way you are doing is the best way to estimate capacity loss. (Just make sure you know the original rating for your vehicle - covered earlier in this Model Y thread or others - and there are sometimes some subtle details which hide a small % of initial loss; these are discussed elsewhere - but for the most part taking ratio of current 100% to original EPA 100% gives a good estimate with foregoing caveats). The estimate bounces around a few %, so just slap some error bars on your capacity loss.

As long as you're above 70% you're good to go. It's extremely common to see 10% loss at your vehicle's age and mileage (better results are also very common). You can see this in this forum and oodles of stories in the Model 3 forum as well as @jjrandorin says. Not going to link to them - you'll have to take my word for it. It's extremely normal.

If you want to slow it down (less impactful now since the loss will be much slower from this point anyway), just charge to 50% or so regularly, and keep cycle depth to a minimum (charge often to 50%); general Lithium-ion battery characteristics suggest that could be the best strategy. This reduces calendar aging (nothing to do with the miles on the vehicle). If 50% doesn't work for you, don't bother, and charge to the level you need to comfortably meet all your daily needs.

At the moment, capacity loss of 15% seems to kind of be the upper limit (this upper limit is increasing every day). Reports of 20% loss are very uncommon, at least at this point in time. I assume we'll get to that point eventually (time!), but not there yet.

Enjoy your car! Sounds like it is doing great. Just a little harder to make it between long Supercharger gaps (in some cases impossible).

 

[Dennisis]

There is a ton of info on the threads referenced, should spend more time there. One significant point you'll see many have made is NOT to give much weight to what your indicated range is at any given time. It's based on the best estimates your battery management system (BMS) can make based on available data given your charging habit's and vehicle settings (sentry mode, etc...). And this info is "parroted" many places based on owners experiences - if you don't find these experiences helpful you're free to move on and draw your own conclusions.

 

[modlyowner]

@jjrandorin
@AlanSubie4Life

Your responses are kind of along the lines of "it is what it is"...which I can accept. But doesn't the whole situation here seem strange to you?

- Tesla won't provide me specific data on my car's battery capacity. I need to use a third party app (whose accuracy is unknown) to determine this. I've never heard of a car company or mechanic witholding diagnostic info that is so fundamental to performance from a car's owner.

- Tesla does not discuss any specifics around capacity loss until the issue crops up, and has made no public/official statements on what, if any, capacity loss is "normal". It is only determined as "normal" because of the many anecdotes posted on this forum and others like it. If 80% of TMC users experienced battery fires, but Tesla remained silent, would we also call that normal? It also goes without saying, but the limits of a warranty are not ever what is construed as "normal" performance for almost any good, much less a car.

- If the consensus on this forum is that 10% range loss in year one is normal, why is Tesla support saying that this number is actually 3-5%?

 

[jjrandorin]

Tesla won't provide me specific data on my car's battery capacity. I need to use a third party app (whose accuracy is unknown) to determine this

No, you actually dont (and any third party app is not necessarily accurate related to this at all).

You can calculate your degradation directly from the information on the tesla screen itself, which is the only thing tesla would accept anyway. The second you start talking to them about "I have (insert some third party app) and it says I have....." they will either politely or less politely ignore you, for the most part.

For calculating it from the information on the screen in the car, see this stickied post (that I sticked, written by @AlanSubie4Life )

Calculating Your Battery's Estimated Capacity Using the Car's Energy Screen

Re posting here and making this a sticky post so it doesnt get lost. @AlanSubie4Life originally posted: =========================================== (originally posted by @AlanSubie4Life. Original thread this appeared in can be found here: ( 2021 model Y scan my Tesla battery size)...

teslamotorsclub.com

If the consensus on this forum is that 10% range loss in year one is normal, why is Tesla support saying that this number is actually 3-5%?

If someone is telling you that, it wouldnt be the first time they were wrong. Lets assume that, because they get that question all day, every day and 10 times on sunday, that they lost track of the fact that they were talking to someone about a model 3 or Y, instead of an S or X which have a different, older battery.

 

[WhiteWi]

Range and degradation questions threads as old as universe. my recommendation is not to worry and be happy.

 

[AlanSubie4Life]

esla won't provide me specific data on my car's battery capacity. I need to use a third party app (whose accuracy is unknown) to determine this. I've never heard of a car company or mechanic witholding diagnostic info that is so fundamental to performance from a car's owner.

The third party app (specifically speaking of ScanMyTesla and similar readers) was shown to match the internal diagnostics for a brief period of time they were both available (due to a service mode bug I believe). It's not very complicated. The meaning of these rated miles is also extremely well understood (and equivalent to SMT for practical purposes) . There's no need to create uncertainty where there is no uncertainty.

Tesla does not discuss any specifics around capacity loss until the issue crops up, and has made no public/official statements on what, if any, capacity loss is "normal".

All we have is the warranty, and data from many, many vehicles (which have selection bias towards reporting higher capacity loss). Why is there a need for anything else? I'd take the warranty as the expectation of Tesla (that vehicles will be BETTER than 70%), after 8 years/100k miles for x% of vehicles. (Where x is a number fairly close to 100.) That's really all we need, and the two datasets/numbers align really well as far as I can see (x is ~100 currently but we're not to 8 years yet).

why is Tesla support saying that this number is actually 3-5%?

Tesla Support is not the same as Tesla, really. There's a small group of engineers (and the people who engineer the warranty) who know what normal is. They're not going to talk about it.

Maybe I'm blasé about this after years of reading about it and discovering that it's extremely deterministic and quite well controlled. But it is what it is. (As you say!)

The 3-5% myth (for Model 3/Y) is definitely floating around out there - I understand you getting that impression. But it's false for the Model 3 (and Model Y, same pack). Some people get that result, either due to their particular environmental conditions and use patterns, or luck, but it certainly should not be EXPECTED.

It's just a matter of adjusting expectations. People should expect 15% after 2-3 years, and they'll usually be pleasantly surprised. (I'm at about 9-10% and have been for over a year.)

Anyway, the good news is you have nothing to worry about. When your car tells you the battery is shutting down (not the 12V) and main battery replacement is required, a rare occurrence, that's when you can worry (and hope it happens in warranty).

 

[jjrandorin]

It's just a matter of adjusting expectations. People should expect 15% after 2-3 years, and they'll usually be pleasantly surprised. (I'm at about 9-10% and have been for over a year.)

Im at either 7-8% or 10-11% depending on if you count my starting mileage number 310 (which it was when I bought the car in 2018) or 299 (which they changed the capacity number to with 20 inch wheels, which my car came with). Its 3.5 years old, but has 29k miles.

 

[modlyowner]

Range and degradation questions threads as old as universe. my recommendation is not to worry and be happy.

Feels like the company should be upfront about the fact in marketing materials that it is completely normal for that range advertised in huge numbers on the website to be 10% less within 12 months, or 15% less in three years. We pay a lot of money for these vehicles and should expect a higher standard of transparency on performance and customer communication.

"Don't worry be happy" doesn't seem like the correct response to poor customer service, but that's just me.

 

[WhiteWi]

Feels like the company should be upfront about the fact in marketing materials that it is completely normal for that range advertised in huge numbers on the website to be 10% less within 12 months, or 15% less in three years. We pay a lot of money for these vehicles and should expect a higher standard of transparency on performance and customer communication.

"Don't worry be happy" doesn't seem like the correct response to poor customer service, but that's just me.

There is plenty of information about battery technology. No reason no to read it before you spend big money on the car that uses that tech. No surprises for me bc I did my research.

 

[jjrandorin]

Feels like the company should be upfront about the fact in marketing materials that it is completely normal for that range advertised in huge numbers on the website to be 10% less within 12 months, or 15% less in three years. We pay a lot of money for these vehicles and should expect a higher standard of transparency on performance and customer communication.

"Don't worry be happy" doesn't seem like the correct response to poor customer service, but that's just me.

Sorry for sounding "short" but there is likely no complaint I havent heard already over 226 pages of pretty much the same exact conversation. Its not that I dont have some sympathy, but "it is what it is".

I personally tend to be a person who shows my displeasure with something with my wallet (by either not buying it or selling it and moving on). Now would be a great time for anyone unhappy to sell their tesla and recoup most, if not all, of their spend on it, and move to something else that might suit them better.

There is no combination of talking about it on this or any other website that is going to change how this plays out. We are telling you 10% is normal, and even if it were not normal, there would be nothing tesla would do about it unless or until it reaches 30% degradation (as measured by the data on the screen, not anything else, no third party tools etc).

We are not saying you have to be happy with it, just that its normal. If you are unhappy with it, then now is a good time to exit out. You say you mostly supercharge, so you do not have the ability to limit your charging much, so you should plan on the car having 10% degradation (ish) after the first year, perhaps 15-17 % after year 2-3 and slowing down from that, or you should plan on selling it now while we are in this once in a lifetime used car market.

There isnt any combination of "I will talk to tesla about" or "maybe tesla will look at", or "what did tesla actually say?" that is going to change any of this.

 

[Dennisis]

You're starting with the premise your battery capacity has degraded further than you expect when the fact is it's doubtful that you actually know how much it's dropped. As stated previously, your charging and usage habits are probably resulting in inaccurate data. Read a bit more about how to change those habits and it's likely you'll be please with the results.

 

[AlanSubie4Life]

Feels like the company should be upfront about the fact in marketing materials that it is completely normal for that range advertised in huge numbers on the website to be 10% less within 12 months, or 15% less in three years. We pay a lot of money for these vehicles and should expect a higher standard of transparency on performance and customer communication.

"Don't worry be happy" doesn't seem like the correct response to poor customer service, but that's just me.

Buyer beware. All EVs have capacity loss, some more than others. My Chevy Spark EV has 30%+ capacity loss after 4.5 years. I basically expected this because every lithium battery I have ever owned for the last 20+ years has behaved exactly the same way. (Check out all the laptops (which report capacity), cell phones, etc.)

Anyone researching buying an EV will immediately discover that capacity loss can be significant (and is managed in different ways by different manufacturers - some build buffer in to the number so that there is much less realized loss (never allow 100% charge initially), others like Tesla do not). If you're going to spend $50k on a vehicle you should realize this. I understand many buyers will not, or won't care. But that's just life with capitalism.

The information is out there if you search for it. Just like for any other purchase.

Similarly, there are best practices for how to care for your battery (see above), which may or may not be desirable for various reasons, and are not guaranteed to lead to an excellent result.

I'm not being an apologist for Tesla. I think they could be more upfront with things. I think there could be federal regulations which set expectations correctly, but that's complicated, and I'm not really advocating for that (not all EVs will behave exactly the same way depending on the battery, etc.).

They don't say it upfront because being upfront would hurt their vehicle sales at the margin (unclear whether it would matter to them given the current market). It changes the perceived value of the vehicle (because people who don't do their research would end up being informed and thus price the vehicle properly).

the fact is it's doubtful that you actually know how much it's dropped.

The mileage method works pretty well. The estimate bounces around. More than +/-3% is pretty rare but we've seen 15% recoveries (very rare, transient event!). It's important (to Tesla) that the estimate is fairly accurate otherwise you can run out of charge unexpectedly. They have a 4.5% buffer so generally I'd expect that it's pretty rare for the estimate to be off by more than about that.

Could a battery showing 10% mileage loss actually recover to 5% loss? Sometimes. Probably pretty rare though and any recovery to that level I would not expect to be sustained.

I'm of course only talking about numbers where the car is charged to 90% plus. Lower levels have tons of error.

 

[modlyowner]

is it's doubtful that you actually know how much it's dropped.

Well, no. I am using both TeslaFi and Recurrent independently. Tesla support won't tell me how much the capacity has dropped, which is odd in and of itself.

This discussion is quickly trending in a typical direction for those who reflexively apologize for Tesla:
- you didn't do your research (pore over random forum posts) - your fault, not Tesla's for hiding the ball
- you are wrong, please read these random anecdotes and become an amateur technician to calculate your car's performance
- you are not operating/charging your car properly - your fault
- don't like it? sell the car

I look forward for posts from users who might have a more reasonable point of view. But your reactions are noted.

 

[WhiteWi]

Good luck.

 

[Dennisis]

Well, no. I am using both TeslaFi and Recurrent independently. Tesla support won't tell me how much the capacity has dropped, which is odd in and of itself.

This discussion is quickly trending in a typical direction for those who reflexively apologize for Tesla:
- you didn't do your research (pore over random forum posts) - your fault, not Tesla's for hiding the ball
- you are wrong, please read these random anecdotes and become an amateur technician to calculate your car's performance
- you are not operating/charging your car properly - your fault
- don't like it? sell the car

I look forward for posts from users who might have a more reasonable point of view. But your reactions are noted.

Yeah OK so your apps must be right? Why post if you just ignore what you don’t already believe?

 

[jjrandorin]

Well, no. I am using both TeslaFi and Recurrent independently. Tesla support won't tell me how much the capacity has dropped, which is odd in and of itself.

This discussion is quickly trending in a typical direction for those who reflexively apologize for Tesla:
- you didn't do your research (pore over random forum posts) - your fault, not Tesla's for hiding the ball
- you are wrong, please read these random anecdotes and become an amateur technician to calculate your car's performance
- you are not operating/charging your car properly - your fault
- don't like it? sell the car

I look forward for posts from users who might have a more reasonable point of view. But your reactions are noted.

if you actually took the time to look through either my or @AlanSubie4Life 's posts, you would absolutely NOT find "tesla apologist".

What "reasonable point of view" are you looking for? People to say "yeah its wrong!!" ? People to complain along with you? You can find plenty of that in the thread I have linked you to a couple times now. "Sell the car" is a reasonable point of view, since its not working for you. Expecting tesla to do something about 10% degradation when the warranty is 30%, isnt.

EDIT:

I am going to leave what I posted here, but am going to dis engage from this thread. However, this is how most of these threads go, which is why I generally dont participate in them. In general, people dont want actual answers to the question of "is there something wrong with my car". They want to talk about why XY and Z are unfair.

In general, I like to help people know whats going on, but dont particularly like online arguments. It sounds like you have the information you now need, so, I wish you the best in figuring the rest out.