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

[Filip K]

They're probably very concerned about lithium plating with this new cell so they're not taking any chances. It's quite irreversible, so why risk it right now, when they're just trying to fully validate a pack from a new vendor?

It could also just be a software bug, if lithium plating is not a concern at 15-16C, where it started, before engaging the heater. I thought that for relatively low charge rates it really should not be a problem until close to 0C. You can see the BMS Max Charge value (looks like the maximum amount of charge power the battery can accept) far exceeds the available power at all times, so it seems like it really shouldn't need to warm the battery.

Interesting data though. Interesting how cell voltage doesn't get all the way to 4.2V. But there's no data on that value when nothing is running (heater was running pretty hard) so hard to say what the open-circuit voltage would be. Maybe it's actually 4.2V.

Definitely, there is a deadline to a max charge / regen power 0 kW when the pack temp is under 0 °C. No regen (0 kW) today at 60 % SoC and 0 °C. You are right, it should be OK if a new pack is heated to 20 °C due to lithium plating. But why 40 °C with 0.15C? The car is now sleeping at 99 % SoC and I will see the values after a couple of hours when the BMS will be done.

 

[jaqueh]

Took delivery of my 2021 Model 3 LR at the end of the quarter q4 push so I got free supercharging for a year! Some panel gap and door closing issues aside...wonderful car! Charged to 95% and drove down to 50%. Trip said 33kWh used, suggesting ~74kWh (+/-1) usable from indicator’s 100% - 0%. Including the 3% buffer I calculate 75.5 usable. So it does seem to indicate we are still getting the old 78 batteries in the US.

Relevant pictures attached.

 

[Npap]

Took delivery of my 2021 Model 3 LR at the end of the quarter q4 push so I got free supercharging for a year! Some panel gap and door closing issues aside...wonderful car! Charged to 95% and drove down to 50%. Trip said 33kWh used, suggesting ~74kWh (+/-1) usable from indicator’s 100% - 0%. Including the 3% buffer I calculate 75.5 usable. So it does seem to indicate we are still getting the old 78 batteries in the US.

Relevant pictures attached.

Nice! Enjoy the car!
If 45% used 33kWh then 100% would be 73.3kWh. Could this mean that this is an LG battery?

 

[AlanSubie4Life]

Nice! Enjoy the car!
If 45% used 33kWh then 100% would be 73.3kWh. Could this mean that this is an LG battery?

No.

32.99kWh/0.45/0.99/0.955 = 77.5kWh

That’s the math. Obviously there is rounding error here, so it should be between 77 and 78kWh.

So it’s a 77.8kWh nameplate.

Including the 3% buffer I calculate 75.5 usable. So it does seem to indicate we are still getting the old 78 batteries in the US

It’s a 4.5% buffer. You have the Energy page set to instantaneous so it isn’t possible to calculate your battery capacity that way. But it is normal at over 77kWh right now.

 

[TimothyHW3]

Some panel gap and door closing issues aside...wonderful car! Charged to 95% and drove down to 50%. Trip said 33kWh used, suggesting ~74kWh (+/-1) usable from indicator’s 100% - 0%. Including the 3% buffer I calculate 75.5 usable

Buffer is 4.5% or 3.5kWh when new.

You have about 77-77.5kWh which suggests that you have the same Panasonic packs we have in Europe, but without the softlock.

Also, it does seem like these Panasonic packs use the new cells as I have data and screenshots at 100% that suggests there is even more room at the top.

What does the car say for miles at 95% or 100%? 563km or so at 100%?

 

[jaqueh]

Buffer is 4.5% or 3.5kWh when new.

You have about 77-77.5kWh which suggests that you have the same Panasonic packs we have in Europe, but without the softlock.

Also, it does seem like these Panasonic packs use the new cells as I have data and screenshots at 100% that suggests there is even more room at the top.

What does the car say for miles at 95% or 100%? 563km or so at 100%?

When adjusting the slider in the app, 100% should be 353 miles.

 

[jaqueh]

No.

32.99kWh/0.45/0.99/0.955 = 77.5kWh

That’s the math. Obviously there is rounding error here, so it should be between 77 and 78kWh.

So it’s a 77.8kWh nameplate.



It’s a 4.5% buffer. You have the Energy page set to instantaneous so it isn’t possible to calculate your battery capacity that way. But it is normal at over 77kWh right now.

I calculated it as 33kWh/(.45/1.045)

 

[AlanSubie4Life]

I calculated it as 33kWh/(.45/1.045)

Yes. That’s incorrect. Could use 1.047 (1/0.955).

The 0.99 represents that the trip meter doesn’t capture every bit of energy used as demonstrated with SMT data. It’s a bit of a fudge factor, but 0.99 is usually pretty close.

 

[TimothyHW3]

100% should be 353 miles

should be or IS? I can't really see 353 in your car with that data. What did 95% give you for miles?

 

[jaqueh]

should be or IS? I can't really see 353 in your car with that data. What did 95% give you for miles?

95% is 335. The app indicates 353 when I move the slider to full

 

[jaqueh]

Yes. That’s incorrect. Could use 1.047 (1/0.955).

The 0.99 represents that the trip meter doesn’t capture every bit of energy used as demonstrated with SMT data. It’s a bit of a fudge factor, but 0.99 is usually pretty close.

How is it incorrect? Math is the same. This way makes more sense to me conceptually.

 

[AlanSubie4Life]

How is it incorrect? Math is the same. This way makes more sense to me conceptually.

All I was saying is 1/0.955 is not equal to 1.045. Admittedly it is a small difference. The main issue is the 0.99 factor; trip meter loses about 1% of the energy. (This is a fudge factor; it varies a bit, but based on many data points, this is a good approximation.)

You can certainly do:

33kWh/(0.99*0.45/1.047) if that makes more sense to you.

As you say, it is all the same. As long as you get all the factors correct.

 

[jaqueh]

All I was saying is 1/0.955 is not equal to 1.045. Admittedly it is a small difference. The main issue is the 0.99 factor; trip meter loses about 1% of the energy. (This is a fudge factor; it varies a bit, but based on many data points, this is a good approximation.)

You can certainly do:

33kWh/(0.99*0.45/1.047) if that makes more sense to you.

As you say, it is all the same. As long as you get all the factors correct.

Got it yeah. The kWh is up to .5kWh off and percent is up to .5% off, so that makes sense. Also, parasitic losses. Car is still pretty efficient though, but same as pre 2021 Model 3's. Looking at your lifetime Wh/mi is very similar to mine.

 

[AAKEE]

I had nominal full pack 80.6 that went to 80.7. Yesterday after work I let the M3P stand in the garage without connecting the charger for 3 hours at 46% then I charged to 90% instead of 70. After letting it stand with complete charge for a few hours and I checked SMT nominal full pack which now say 81kwh. The cell imbalance is cut in half to 4mV instead of 8.
Decided to charge to full for the fotst time, will go for a small trip when the charge is complete.

 

[AlanSubie4Life]

95% is 335. The app indicates 353 when I move the slider to full

@TimothyHW3 really was convinced that US Model 3s wouldn't display ~353 rated miles at 100%, and tried to bet me $1000 that they wouldn't (I refused to take his money)...that's why he's so interested.

Seriously, though, I'm not sure why he's asking - we already have multiple datapoints in this thread showing that US market Model 3s now (after a late-2020 software update which adjusted the constant, as documented here) have the full 353 rated miles (~77.8kWh). But, it's always good to have another one! Thanks.

I'd go back and substitute in the links to each individual post in this thread showing this, but feeling a bit lazy tonight, so I just included one of the links here.

 

[Marius A]

Here's my battery stats, just installed obdlink and SMT

 

[AAKEE]

So you have a Performance also? ( 82.1kwh-battery)

 

[Marius A]

So you have a Performance also? ( 82.1kwh-battery)

Yes

 

[TimothyHW3]

obdlink and SMT

Did the foot OBD II work or did you need the extra adapter cable in the midle console? Can you please charge to about 90+% and see at what kWh you reach 4.14 to 4.15V?

 

[AAKEE]

I also have a ’21 M3P with the 82kwh batt.

Charged to 91 the other day for balancing purpose.

SOC 91% and 4.12V/cell. 10 degree C in the garage if it have any input on voltage.
[Edit] found Nominal remaining 73.00kw and SOC 89.66% on another pic from the same time.

BTW, wheres the ODB2 Didnt think there was any so I use the ODB-connector in the middle console.