Vendor Official Tessie app talk

[AlanSubie4Life]

James@Tessie, given that the "Usable Capacity" on the health page includes the buffer, should we be using the nominal original capacity in order to get an accurate before and after capacity comparison? For example, for my 2019 Model 3 SR+, Tessie recommends 51.6 kWh for the original capacity:

View attachment 924375

...but I believe that would be the "original usable capacity" and does not include the buffer. So should I bump that to the original nominal capacity to include the buffer to match the current capacity which also includes the buffer? If so, does anyone know what the original nominal capacity of my model would be?

Original capacity for that vehicle is 52.5kWh to show 240 miles. If you have less than that, you will not show 240. Most (but not all) vehicles started with at least that. And usable initially is 95.5% of this, 50.1kWh. So each of the 240 displayed rated miles has an energy content of 50.1kWh/240rmi, or 209Wh/mi.

The buffer is always (for Model 3/Y) 4.5% of the nominal full pack. 95.5% of NFP is the usable quantity.

This is all extremely well documented here with rock-solid evidence base. Just search for 52.5kWh and look for screen captures and pictures of the range. Or 209Wh/rmi or 209Wh/mi.

Charging constant is 219Wh/rmi.

As you can see, it is straightforward to determine your current usable and full pack capacity with this info.

Note for the 2020 it went to 250rmi with no relevant change to the pack or vehicle. That was a software update which also applied to your car to improve efficiency, but did not change your constant (since that is not changed from the EPA value - which was better in 2020 than 2019 (2018 actually I think) because of these several updates). 210Wh/rmi or 200Wh/drmi.

 

[johnny_cakes]

Original capacity for that vehicle is 52.5kWh to show 240 miles. If you have less than that, you will not show 240. Most (but not all) vehicles started with at least that. And usable initially is 95.5% of this, 50.1kWh. So each of the 240 displayed rated miles has an energy content of 50.1kWh/240rmi, or 209Wh/mi.

The buffer is always 4.5% of the nominal full pack. 95.5% of NFP is the usable quantity.

This is all extremely well documented here with rock-solid evidence base. Just search for 52.5kWh and look for screen captures and pictures of the range. Or 209Wh/rmi or 209Wh/rmi.

Charging constant is 219Wh/rmi.

As you can see, it is straightforward to determine your current usable and full pack capacity with this info.

That's great information, thank you! I didn't realize the original capacity was only 52.5kWh. It's incredible how efficient Teslas are compared to the competition that they can be rated at 209Wh/mi & 240 original miles.

James@Tessie, is this (52.5) the original capacity that I should be entering into Tessie in order to get an accurate degradation number? Unfortunately I only started using Tessie a couple of months ago so I don't have the full historical data.

 

[AlanSubie4Life]

Teslas are compared to the competition that they can be rated at 209Wh/mi & 240 original miles.

The RWD vehicles are incredibly efficient. And they got even more efficient after that model year with software, and even more so since they got the heat pump (the 263rmi is accomplished with 53.5kWh though IIRC).

The AWD vehicles not so much. Hopefully the next generation mostly fixes that problem, with PM in the front. And maybe we could get some carbon-sleeved rotors as well. And more power; 750HP would be good with minimal dropoff.

 

[AAKEE]

...but I believe that would be the "original usable capacity" and does not include the buffer.

Full Pack When New 52.4kWh in the SR+ ’19.
Which is the total capacity including the buffer.
The buffer is always 4.5% of the Nominal capacity, so a new pack that is 52.4 kWh had a buffer of 2.358 kWh.
In this case the battery have degraded to 46.7 kWh, and the buffer is 4.5% = 2.10 kWh.

 

[AlanSubie4Life]

Full Pack When New 52.4kWh in the SR+ ’19.
Which is the total capacity including the buffer.
The buffer is always 4.5% of the Nominal capacity, so a new pack that is 52.4 kWh had a buffer of 2.358 kWh.
In this case the battery have degraded to 46.7 kWh, and the buffer is 4.5% = 2.10 kWh.
View attachment 924379

I think we have screen captures showing the rated line at 224Wh/mi (which means (rounded) 219Wh/mi charging constant, or greater than 218.5Wh/mi…which would be 52.44kWh…which would round down to 52.4kWh…).

Degradation thresholds are always set less than or equal to FPWN as far as I know (assumed here).

If FPWN > deg threshold and
FPWN = 52.4kWh (known)
Assume Deg threshold < 52.44kWh
=> constant < 218.5Wh/rmi
Therefore assumption is false.
So deg threshold must be >= 52.44kWh
But since it must be less than FPWN then it must be < 52.45kWh.

So 52.44kWh<= FPWN = deg thresh < 52.45kWh.

Probably, lol. I think this is WAY too much precision. But would be consistent.

 

[Adopado]

Original capacity for that vehicle is 52.5kWh to show 240 miles. If you have less than that, you will not show 240. Most (but not all) vehicles started with at least that. And usable initially is 95.5% of this, 50.1kWh. So each of the 240 displayed rated miles has an energy content of 50.1kWh/240rmi, or 209Wh/mi.

It's a thorny question though. I have seen "useable capacity" figures for the SR+, from apparently reliable sources, that quote 49kWh, 50kWh, 51.6kWh, 52.5kWh and 52.6kWh! Obviously that doesn't include the SR+ that introduced the 60kWh LFP pack (made in China, delivered to European countries.) I honestly can't remember what my own Fremont SR+ displayed in total miles when new.

 

[AlanSubie4Life]

It's a thorny question though.

Not really. To within a small fraction of a kWh, you can just look at the energy screen and get the charge constant and go from there. See above.

That’s how this works. Admittedly that is for the degradation threshold - but we know these vehicles quickly lost range so the actual capacity was very close to that level when new.

The reliable sources are not so reliable. Just use what your car tells you is required to show your full rated range!

The best part is you can just figure it out for yourself and prove to yourself that that is the right answer. Tesla doesn’t hide anything (except excess capacity above the threshold when new).

I honestly can't remember what my own Fremont SR+ displayed in total miles when new.

It’s true that some people take delivery of a car that does not show the full EPA range, but this is generally the exception rather than the rule. Since if it wasn’t Tesla would be delivering vehicles with capacity that does not closely match what the EPA results require.

 

[Adopado]

Just use what your car tells you is required to show your full rated range!

I know what my range is now if I do the check at 100%. It's slightly higher than what Tessie predicts and I don't know for sure what it said initially because I didn't charge to 100% in its first year. I've only had Tessie over the past few months so I don't have a full history. I also now know that a couple of 100% charges makes a few miles difference due to BMS calibration. I've seen as low as 216 and Tessie predicts 218 but recent 100% charges show 222 on the car, and as Tessie gathers more information it is actually showing my degradation reducing rather than increasing.

 

[AlanSubie4Life]

I know what my range is now if I do the check at 100%.

I don't know for sure what it said initially because I didn't charge to 100% in it's first year.

Sure. As I said, hard to know that 100% for a specific vehicle. However, in general most vehicles showed the full rated range when brand new (you can just look at old posts - and I mean brand new).

And then even right now you can determine what level is required to show that EPA 240mi (2019 model year), in your current car even if you personally were never there. Just do the calculation. It’s deterministic. There are 3-4 ways to get the charging constant, listed recently elsewhere.

In spite of it being described many times here, it is not widely known how this works, I guess. And there is no debate because none of my claims have to be believed. It is all in the car and can be deduced through observation.

At 218 currently for your 2019 it is very likely you once showed 240. That is just a good result.

 

[AAKEE]

It's a thorny question though. I have seen "useable capacity" figures for the SR+, from apparently reliable sources, that quote 49kWh, 50kWh, 51.6kWh, 52.5kWh and 52.6kWh! Obviously that doesn't include the SR+ that introduced the 60kWh LFP pack (made in China, delivered to European countries.) I honestly can't remember what my own Fremont SR+ displayed in total miles when new.

Seems like you have looked at the Tessie number, hence the "usable capacity" term?

I have seen more or less *any* number of the original capacity in Tessie examples. Most often we do not se the specified full pack when new, but numbers well below and people think that that is the "when new value" without the buffer. Which is wrong. They also think that they have way lower degradation they they actually have.
Discussing degradation I put my 4% in the discussion (78.8kWh nominal full pack, from 82.1) and they say I have only 2.9%, but the screen shows "usable capacity" 75 kWh. So the direct conclusion they draw is that they have less degradation than I have despite charging to 90% daily so they find that much better to do. They also are supported by the Tessie home site information about how to take care about the battery, which information I do not agree with.

 

[Adopado]

Seems like you have looked at the Tessie number, hence the "usable capacity" term?

Of course ...

 

[johnny_cakes]

And they got even more efficient after that model year with software,

It's too bad that they didn't retroactively apply that software improvement range increase to older models. I've heard that they've done something like that in the past, but perhaps not to the 2019 M3?

 

[johnny_cakes]

Thanks @AlanSubie4Life and @AAKEE for those capacity numbers. It sounds like the original nominal capacity for 2019 M3 SR+ was between 52.4 and 52.5 kWh. FWIW, here's my updated Tessie numbers. It's a little disappointing that it's got 11.5% degradation already, especially since I'm not in a high climate (Vancouver, Canada), but I suppose it's pretty normal for an almost 4 year old M3. It felt a little better when I was using Tessie's recommended 51.6 kWh starting value, LOL!

The estimate seems to be climbing and I got a bit of a boost a few days ago when I charged to 100% and let is sleep there for a couple of hours, so I'll see where it goes from here.

 

[AlanSubie4Life]

It's too bad that they didn't retroactively apply that software improvement range increase to older models.

They did, AFAIK. Your car has better “range” (Edit: I mean efficiency) (for a given drive) than when it was sold. Has nothing to do with this other stuff though. That update affected actual efficiency. It doesn’t matter what the car says.

 

[johnny_cakes]

They did, AFAIK. Your car has better range (for a given drive) than when it was sold. Has nothing to do with this other stuff though. That update affected actual efficiency. It doesn’t matter what the car says.

Oh that's great to hear

 

[AlanSubie4Life]

Oh that's great to hear

This was very poorly stated. No coffee.

I mean you have better efficiency. What the car says of course does matter - it affects the energy you have left. (I meant it is not a reflection of your efficiency or whether you got the update and does not matter in that way.) Otherwise the rated range wouldn’t matter. But it does. Affects your energy. But not a reflection of efficiency.

But what I mean (to be clear (?) ) is that this software update improved your efficiency but did not change the constant (energy in each mile). The 2020 with 250 miles when new has miles that contain less energy than your miles since it has more with the same total energy (because it is more efficient with the new software it was tested with).

And both vehicles received about the same update. Per announcements at the time.

 

[johnny_cakes]

I mean you have better efficiency. What the car says of course does matter - it affects the energy you have left. Otherwise the rated range wouldn’t matter. But it does. Affects your energy. But not a reflection of efficiency.

This makes sense. As I understand it, the EPA range didn't change, so the the software update didn't impact the rated range remaining (i.e. charge to 100%, rated range stayed the same). But the real world range increased after the software update due to the improved efficiency. Let me know if I misinterpreted anything.

But what I mean (to be clear (?) ) is that this software update improved your efficiency but did not change the constant (energy in each mile). The 2020 with 250 miles when new has miles that contain less energy than your miles since it has more with the same total energy (because it is more efficient with the new software it was tested with).

This is really fascinating. So the 2020 model has a higher rated range (250 miles instead of 240 miles) with the same battery and the same software? The only difference is that when they were tested, the 2019 model had software before the efficiency update and 2020 had software after the efficiency update, so the 2020 is rated higher, but actual real world range is the same between the 2. Did I get that right?

 

[AlanSubie4Life]

The only difference is that when they were tested, the 2019 model had software before the efficiency update and 2020 had software after the efficiency update, so the 2020 is rated higher, but actual real world range is the same between the 2. Did I get that right?

Yes. That is what I am saying. Wish I had thought of saying it that way.

Now, of course, there presumably are changes between the two years, but none that likely impacted the efficiency. (However, I of course don’t know that for sure.)

Evidence: There were several publicly announced software updates to improve efficiency to existing vehicles (and announced as such) during this intervening time period.

 

[jpbcx43]

@James@Tessie Can't say enough about Tessie! I wanted to make a feature request if possible. Similar to TeslaFi, I would love to have climate presets. Would be great to set the temperature, configure seat and steering wheel heat levels, all at once. I'm currently doing this with several actions.

Would also be great to send a preset to the car, whether automated or not. Not sure if this has already been requested, or is on the roadmap, but it would be awesome.

Another thing I would love is the ability to view certain status of a drive, such as average tire pressures, what the climate was set to, avg fan speed, etc. Also similar to TeslaFi, but more of a nice to have vs a need.

 

[johnny_cakes]

So each of the 240 displayed rated miles has an energy content of 50.1kWh/240rmi, or 209Wh/mi.

Charging constant is 219Wh/rmi.

@AlanSubie4Life What's the difference between the energy constant and the charging constant? I think I understand the energy constant as the rated energy consumed for every mile driven, but curious about the charging constant. Is that the amount of energy added to the battery during charging for every rated mile increase in the available range? Does the difference between the 2 reflect the loss in a charge + discharge cycle?

Note for the 2020 it went to 250rmi with no relevant change to the pack or vehicle. That was a software update which also applied to your car to improve efficiency, but did not change your constant (since that is not changed from the EPA value - which was better in 2020 than 2019 (2018 actually I think) because of these several updates). 210Wh/rmi or 200Wh/drmi.

Where did the 210Wh/rmi and 200Wh/drmi come from? On that note, what is 'drmi' (sorry, still pretty new to all of this ).

Thanks in advance!