MASTER THREAD: 2021 Model 3 - Charge data, battery discussion etc

[FredMt]

@ AlanSubie4Life, here are energy screens from 100%. It stay at 100% /506km during 3,3km.

 

[FredMt]

Unfortunately, really need the energy screen (which tells you how much energy you have left). Calculating Your Battery's Estimated Capacity Using the Car's Energy Screen

Yes i know, it was just to show you before. Look at time. Screen seems to be cap at 507, but you can see, it go on charging during a long time.

 

[AlanSubie4Life]

And from 100%

If you could take just one more, in distance mode, corresponding to the 98% picture, that would be great. Just to avoid any ambiguity, take at the same time (when stationary!), one in each display mode, not at 100%. You can (and should) be in park for these pictures. For safety, and it also improves the data since you're taking two pictures which are supposed to be at the same energy level.

It can be lower than 98% of course.

EDIT:

However, I think we have what we need (since your car does not charge to 508/509km - if it charged to 508/509km we'd need the above, but it doesn't):

Constant is ~159.65Wh/rkm (we'll call it 160Wh/rkm but it's probably 257Wh/mi).

And your energy at max is 80.8kWh or so. (396km *204Wh/mi = 80.8kWh. 80.8kWh/506km = 159.7Wh/rkm = 257Wh/mi)

This constant does seem different than in the past. So it seems like it has now changed twice:
1) The first time it was a constant adjustment with constant energy (so just bookkeeping). I'd have to review this thread to see the concrete evidence for this, but we have a datapoint from @AAKEE. Just not sure about energy screen captures. For sure the constant adjusted, no question - it's just a question of what the exact limit was and the exact constant...
2) Now they seem to have increased the available battery limit, while keeping max display km the same, which means a larger constant. The evidence for this is pretty clear (though I'd like to see the energy screen from someone with a very high capacity battery).

The new battery limit (pending details from someone over the cap) seems to be 508.5km*159.7Wh/rkm = 81.2kWh.

I'd expect that this limit can be exceeded (it's a display limit I think, not an actual limit on max capacity), and it would be very interesting to see an energy screen capture (both % and km at the exact same time) from someone who does exceed it (both fully charged and also at lower charge).

 

[FredMt]

If you could take just one more, in distance mode, corresponding to the 98% picture, that would be great. Just to avoid any ambiguity, take at the same time (when stationary!), one in each display mode, not at 100%. You can (and should) be in park for these pictures. For safety, and it also improves the data since you're taking two pictures which are supposed to be at the same energy level.

It can be lower than 98% of course.

EDIT:

However, I think we have what we need (since your car does not charge to 508/509km - if it charged to 508/509km we'd need the above, but it doesn't):

Constant is ~159.65Wh/rkm (we'll call it 160Wh/rkm but it's probably 257Wh/mi).

And your energy at max is 80.8kWh or so. (396km *204Wh/mi = 80.8kWh. 80.8kWh/506km = 159.7Wh/rkm = 257Wh/mi)

This constant does seem different than in the past. So it seems like it has now changed twice:
1) The first time it was a constant adjustment with constant energy (so just bookkeeping). I'd have to review this thread to see the concrete evidence for this, but we have a datapoint from @AAKEE. Just not sure about energy screen captures.
2) Now they seem to have increased the available battery limit, while keeping max display km the same, which means a larger constant. The evidence for this is pretty clear (though I'd like to see the energy screen from someone with a very high capacity battery).

The new battery limit (pending details from someone over the cap) seems to be 508.5km*159.7Wh/rkm = 81.2kWh.

I'd expect that this limit can be exceeded (it's a display limit I think, not an actual limit on max capacity), and it would be very interesting to see an energy screen capture (both % and km at the exact same time) from someone who does exceed it (both fully charged and also at lower charge).

Here are 2 pictures after with distance.

 

[AlanSubie4Life]

Here are 2 pictures after with distance.

To be clear this is what I mean:

Must be stationary...otherwise the two numbers are harder to line up (though the delta in the trip meter does help back calculate the error I suppose...but it can take a while to update so stationary is better).

Again, ideally I'd like to see from someone with a very high capacity battery:
1) Absolute 100% energy screen, both in %, and in km (but obviously it's going to be 100%), at absolute max (SMT capture too, to see what actual BMS value is). If there are two km values, capture them...seems like 508/509km are the numbers in this case.
2) Two energy screen pics soon thereafter, same vehicle, at something like 90-95%, both in % and in km, while stationary.

Would clear up some mystery maybe.

 

[FredMt]

Must be stationary...otherwise the two numbers are harder to line up (though the delta in the trip meter does help back calculate the error I suppose...but it can take a while to update so stationary is better).

Sorry AlanSubie4Life, these pictures were taken almost 2 months ago. I understood and I will do as you said next time thank you again!

 

[AlanSubie4Life]

Sorry AlanSubie4Life, these pictures were taken almost 2 months ago. I understood and I will do as you said next time thank you again!

That's even better, actually - that kind of suggests we just had the wrong constant value calculated a couple months ago (due to lack of good data), and it may be that the current value is what it has been since they changed it, to give you the 508/509km rather than 499/500km. So rather than a recent change, there has been no change. Just one change.

Makes another set of pictures (at your convenience) showing things are still exactly the same even more helpful. Doesn't require a 100% Supercharge to get some information.

It's very hard to determine this information without actually having a vehicle in possession. There just aren't a lot of people taking pictures of this stuff and correlating with SMT data. Bjorn does occasionally but that's not his primary focus so it's difficult to get the info.

 

[AAKEE]

If possible, if you could also take an energy screen picture as described above, that would be helpful. Here is the sample to avoid any confusion: Calculating Your Battery's Estimated Capacity Using the Car's Energy Screen

I might do another trip to the closest SuC to fo another full charge.
I took a lot of pictures but I also bought a new iphone when I waited for the Service at SC. I have now switched the data over and I did throw away a lot of photos during this, and most of the photos from the Supercharging session is gone.
I know I didnt have the energy app photos anyway so.
I see the use of the energy app to get the constant, but I would guess the energy app use the nominal remaining as the base for that calculation? All my calculations have been quite close to the energy app so far. Most probable it has been within the rounding errors of whole percent.

 

[AlanSubie4Life]

I see the use of the energy app to get the constant, but I would guess the energy app use the nominal remaining as the base for that calculation?

I'm not sure; you could answer the question though. (As discussed previously (in this thread I think), the actual kWh value it uses for the calculation is a scaled (by the SOC) version of something like Nominal Full Pack (which exact Nominal value is used (there are two in SMT) I am not sure). In other words, because of this scaling, the amount of the buffer included in the kWh value used for the calculation is scaled by the SoC. None of the buffer is included at 0%, 90% is included at 90%.)

and most of the photos from the Supercharging session is gone.

That's ok, you could take new ones now! And there's no reason to wait for a Supercharging session. For your car (since it has a very high nominal full pack), even values (% and km) taken at above 80% SoC (90% would be awesome) would be very helpful. At exactly the same time - an SMT capture showing what is your Nominal Full Pack and Nominal Remaining (or whatever it is called). The primary reason is that it would allow us to determine which "nominal remaining" value is used for this energy screen. Obviously the higher the SoC the better the accuracy, so at 90% it might not be good enough, depending on rounding error (only two significant figures...). You can also switch to the Trip page if you're navigating somewhere close (the closer the destination the better the zoom works) and you can apparently interpolate your SoC % (hit the + magnifier in the upper right hand corner to zoom in), though I have not tried this to see how well it works - and maybe get the one extra significant digit we need. Just make sure they are taken when the car is in Park.

So three simultaneous pictures (maybe 4 if you include the interpolation picture below):

%. (Energy screen, capture all three numbers)
km (Energy screen, capture all three numbers)
SMT captures of nominal remaining, nominal full pack, remaining to full (not sure if you have to be plugged in for that, charge slider would have to be set to 100% regardless), etc. - all the relevant values.
Extra credit: Energy Screen, Trip page, navigating somewhere nearby, zoom in.

You don't need to drive anywhere or do anything other than take the pictures. Capture them all within 30 seconds of one another if possible (that battery is constantly draining!), and make sure climate control is completely off. It is possible that a cold pack could throw the numbers off (I'm not sure - but SMT will tell you), but you could just check after a nice long somewhat fast charge at home. Your discretion.

The same thing captured after a 100% Supercharging session would be awesome (for documentation purposes), but just a bonus, and not strictly necessary right now since we know you have a very high energy nominal full pack (81.5kWh+) and we know what your rated km max out at, already. Such captures WOULD help us understand how the energy screen behaves when the energy cap (81.2kWh?) is exceeded. It's never been done, to my knowledge, or at least not documented.

For example, this is about 75.7% SoC...

 

[TimothyHW3]

Found this interesting Performance Video from Switzerland with 90km/h.

Beeing Switzerland it wasn't very flat, so there surely was some regen in the calculation, but nevertheless he managed to pull 75kWh, with about 2% or 1.6kWh to spare and 3.6kWh below 0%.

Makes total 80+kWh and if we factor in 500Wh heat loss then the 81-81.5kWh are realistic.

 

[AlanSubie4Life]

Found this interesting Performance Video from Switzerland with 90km/h.

Beeing Switzerland it wasn't very flat, so there surely was some regen in the calculation, but nevertheless he managed to pull 75kWh, with about 2% or 1.6kWh to spare and 3.6kWh below 0%.

Makes total 80+kWh and if we factor in 500Wh heat loss then the 81-81.5kWh are realistic.

Yep, sounds like exactly what would be expected. Not optimal since he was sitting there in Park for a bit, but at least he had the climate control completely off while doing his talking (very important!), so the test is probably pretty good.

Of course, he could have just switched to the Energy -> Consumption screen and got the answer without any driving. But this was for science.

You should expect to be able to extract 81kWh*0.955*0.99 = ~76.6kWh to 0% from a Model 3 battery that shows on the Energy Screen as containing 81kWh when at 100%.

 

[FredMt]

Makes another set of pictures (at your convenience) showing things are still exactly the same even more helpful. Doesn't require a 100% Supercharge to get some information.

I took some pictures this morning after charging to 80% during last night. Note that i don t have SMT, sorry. We have also to keep in mind that for the last 2 months, my car has been in my garage most of the time because of teleworking, and SoC has been kept on average around 60%.
(Edit : I drive with überturbine wheels at the moment).

 

[AAKEE]

I'm the actual kWh value it uses for the calculation is a scaled (by the SOC) version of something like Nominal Full Pack (which exact Nominal value is used (there are two in SMT) I am not sure)

Well, it should be quite safe to guess that the NFP is the value that the BMS thinks the battery capacity approximately is. Probably there is a uncertainty about exact capacity, a plus or minus value, and the nominal full pack is the approximately middle. We could call it BMS best guess, I guess.
Id say the NFP is used for the range calc on the energy app.

Nominal remaining, should be how much energy the BMS thinks the battery approximately holds at the moment, with the same uncertainity.

In SMT theres a clear connection between the NFP and the ”Full Rated Range”, shows the full range with full battery but in turn max out to the EPA range. (508km for my ’21M3P with 315mi EPA).

There also seem to be a clear connection between the Nominal remaining and the ”Rated Range”, which seems to be the same as the presented range on the screen. Shows the same and also maxed out at 509km.
I guess all BMS data needed is present in SMT values to perform the calc’s but I will of course secure the energy app values as well.

 

[AAKEE]

and 3.6kWh below zero

Its even 3.7kWh when you go NFP above 81.0kwh.

 

[conv90]

I took some pictures this morning after charging to 80% during last night. Note that i don t have SMT, sorry. We have also to keep in mind that for the last 2 months, my car has been in my garage most of the time because of teleworking, and SoC has been kept on average around 60%.
(Edit : I drive with überturbine wheels at the moment).

It seems you are perfect 78%
So on calculations : (159Wh/km * 394 km) / 78% = 80,31 kWh
good also that km on capacity are 395 and the km onEnergy screen is 394 confirming the 159 Wh/km constant

 

[conv90]

Stone cold car (not used since yesterday night) cell temp 18°C
I presume it's 54,3% based on screen energy trip.
SMT SOC is 54,6% and SOC expected 54,1%
So made calculations on 25km history and 50 km history I have about 79,7 kWh

 

[TimothyHW3]

Just drive your car and stop worrying about 0.5kWh. It will be gone soon so or so. You can expect around 10% degradation over the lifetime of the car.

 

[mpower99]

Just drive your car and stop worrying about 0.5kWh. It will be gone soon so or so. You can expect around 10% degradation over the lifetime of the car.

To me it's more like a fun science project to learn more about Tesla's battery tech and which battery is in the newest LRs. I don't think anyone is going to cry about plus or minus 0.5kwh

 

[AlanSubie4Life]

I took some pictures this morning after charging to 80% during last night. Note that i don t have SMT, sorry. We have also to keep in mind that for the last 2 months, my car has been in my garage most of the time because of teleworking, and SoC has been kept on average around 60%.
(Edit : I drive with überturbine wheels at the moment).

It does seem likely we had the constant about right (around 159Wh/rkm, and in fact slightly lower as pointed out above...80.6kWh/316mi = 255Wh/mi = 158.5Wh/km). I use 316mi because of @AAKEE ’s observations above about 508/509km...

I am not sure what is going on with your trip % though - it seems way off - 82.5% rather than the actual 78%??? A bug? (I’ve never used this info before to try to interpolate SoC % so maybe it is unreliable. It was fine in my car...)

The only thing a bit inconsistent is @AAKEE ‘s observations, but that may be because he has a pack which exceeds the 80.6kWh “cap.” The constant may get inflated in that case - would be great to see his results at a lower SoC and a very high one as detailed above. It’s rare to see data captured in that “over the cap” state from SMT and the energy screen.

 

[DeltaOne]

I've had my 2021 Model 3 SR+ for almost two months. Installed TeslaMate soon after taking delivery, so I have lots of data. I saw the sticky post about using the car's energy screen to calculate battery capacity and decided to track my battery. Here's what I started today:

Does that look right so far? How often should I record data? Once or twice a year?

I looked for the Model 3 SR+ battery specs and saw both 50 and 55 kWh. Which is right?