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

[Devils son]

Cool. Interesting. No idea what to make of the reports. So hard to know, with a lot of drama involved. Maybe it is different in different cars - and of course we have the LR vs the Performance difference as well. Maybe there is really no issue with Performance?

I wouldn’t say that there is no problem, because driving to 0% in low temperatures is not working properly.

But as always with Tesla, problems tend to be exaggerated. With minus 25 the Performance might not perform well, but that is extreme and I don’t think these extremes should be put out there as the norm.

 

[AAKEE]

I drove down to 6% when reaching the SuC on the way from picking up my ’21 performance which is about a 1000km drive.
Was about -6 degrees Celcius, had a navigation to home running so I did get the automatic battery preheating. It was a 110 km/h highway in the middle of the night so a
I had a slight ”tax” added on the speed, maybe about 120-125 km/h( 75-80mph)..
I did read about this issue before picking up the car an I sid try to floor it when I was around 20%. It was just a brief WOT, but I could feel the power being less than normal( no SMT mounted at that time).
Still, I could keep the highway speed until I left the highway( at 7% SOC) so I didnt have any problem traveling with the power curve of the battery.

Im happy with the battery power curve.
It tells me, either Tesla has limited it before having enough data on this new 2170L cell( low on cobilt?), or Tesla now it suffers more from low temps+low SOC and limits the power to keep it safe. The heat pump seem to make the battery cooler than the old performance which could not use battery heat to heat the coupe. I guess the old battery would not perform very much higher if the cells had the same temperature.

From all I know so far, it tells me Tesla takes the responsability to keep the battery safe so the driver dont need to be a Lithium battery engineer. Im happy with that approach from Tesla and also from my 15 year experience with lithium batterys I know they usually is sensitive to both high power at low temperatures and high power below 20% SOC. Ive seen a lot of lithium cells( Lipo) dy from being used wrong, mostly my friends and I also seen my own live very long despite being in a hard environment.

My thinking is that, even if Tesla has made electric car living much like ICE-car living there are differences. You either need to accept the nature of current battery technology or you maybe need to drive ICE-cars for a while further.

I have a hobby car that can do 10-11s and 205km/h 127mph on the quarter mile. For that car it really comes to live above 120 kmh where I can use full power without wheel spin.
Tesla dont use any gears and loose power above 100 or120 km/h. This high speed loss of power is worse to me than low power at very low SOC(which I wount use anyway) but still as I understand why this happens I can accept it. If I couldnt, I would have got a high performing ICE car instead.

I do not try to defend Tesla and I see people having problems accepting the low power@low SOC, but from my point of view this is the limitations of the current battery technology. Maybe in the future we get a separate battery heat function to keep it warmer if needed.

 

[MasterC17]

( I might have already posted this)

This is values I got with Scan My Tesla:
It was -25C outside and I only had the car inside the garage for about one hour before this test, after a 50km drive from work.
The power is the actual battery power (power delivered from the battery) according to SMT. The Max discarge power seems to shows a lower value.

M3P refresh 2021:
30% SOC = 292hp /215kW (battery +6C)
25% SOC = 245hp /180kW (battery +8C)
20% SOC = 210hp /150-160kW( battery +10C)

I didnt test power below 20% SOC as I know from other lithium battery implementations that that is a hard hit on battery life.
In the other implementation which use high power we know for sure that going below 20% drastically reduces the battery life.
I do not need a lot of power below 20% SOC, as I wont use it.

I guess I don't understand. It's -25C outside, and the car was parked in the garage for an hour, after a 50km drive - I'm 100% certain the battery pack is not even close to optimal temperature without even knowing the actual values. 50km (30 miles) is not a long enough drive to fully warm up the battery on a 0C day, nevermind a -25C day. And then the battery cold-soaked for an hour. You aren't going to have full power no matter your SOC.

I think this comes down to people expecting the battery pack to warm up much faster than is actually possible in really cold weather. 10C battery temperature (50f) is too cold for full power. You aren't going to see "full" power until ~27C (80f). I realize the limiting dots go away around 16C (60f), but you are limited even then to some degree.

The solution comes down to Supercharging during road trips, and pre-conditioning the battery at home at higher levels of SOC before a drive. I am fairly certain if you home charge to 80%, pre-condition, and then go on a 240km/150mi drive the battery pack will be warm and deliver decent power even at lower SOC (20%) levels.

FWIW, I am not personally seeing a behavior change from the 2018-2020 Models, just some bad data (not saying it was on purpose), misinformation, and a lack of experience with EV's. If anything, my 2021 battery is consistently warmer parked in low ambient temps than either of the 2018's are.

 

[Everybody]

There is more data in the latest video from Bjorn :

Even starting with an hot battery, with an external temperature <6-10°C, the battery is cooling down too much on the 2021 version.

 

[AAKEE]

I guess I don't understand. It's -25C outside, and the car was parked in the garage for an hour, after a 50km drive.

The car was preheated at work with the planned trip before leaving work. There was no power- or regen limitation on the power/regen bar when I left work. I think the car used about 7% SOC during this preheating.
If you have a ’21 refresh with heatpump you might have seen the battery actually get cooler after departing from preheat( indivated by some dots on regen).

I did drive 50km after preheat and i left it in the garage which keeps +10c( but colder after opening and putting the car in).

I did on purpose not navigate to a SuC which would preheat the battery, because:
1) I already did this once and as I described at that time I had no problems with keeping highway speeds as ”TeslaBjörn” had.
2) I did this test because people on a swedish forum ranted about the M3P 21 not being able to be driven at all on highways. As for the battery temps, you can se them in my post, for each SOC.

At least it shows the ’21 M3P having enough power to be used on highways even if the battery isnt preheated for SuC( as I did once down to 6%SOC). It also shows that with cold battery we do not get 400kw at low SOC.

The ’21 refresh uses heat from the battery to heat the driver compartment in some scenarios. This cools the battery and give us performance hit. There most probably isnt any difference between US and EU in that area, because the whole idea with the heat pump and octovalve is to get very energy efficient.

The battery gets drained from heat as we see on the regen dots coming during driving and further on the drive the battery regains temp(most probably the heat loss in the battery). The car ”lends heat energy” from the battery that otherwise would be taken from the battery SOC. And the battery slowly get heated by itself anyway so there is no need to heat it with battery SOC. A smart solution.

I dont think that the people co plaini g snout this issue would accept the need to drive 150 or 250km to heat the battery to get the power. In fact, I guess the heat pump/ octovalve use any excess heat to heat the cabin and that the battery will not get ”high power warm” at all, despite a long trip.
( again, the whole idea with heat pump/ octovale is to make the very best use of any energy available).

As it looks from your power curve, it isnt a ’21 refresh. Unless maybe preheated for a Supercharging session?

 

[AAKEE]

Even starting with an hot battery, with an external temperature <6-10°C, the battery is cooling down too much on the 2021 version.

The vaules in that graf is quite close to mine SMT values for 30% and 20% ( I didnt try below 20%)

 

[Oktoberfest]

New tests from Bjorn shows the 2021 LR is faster from SoC 40% and lower than the 2021 Performance!

 

[srk67]

Did he state ambient temp anywhere?

 

[Oktoberfest]

Sorry I haven't seen #784 when writing my post and can't edit it, please delete.

 

[AAKEE]

I wouldn’t say that there is no problem, because driving to 0% in low temperatures is not working properly.

But as always with Tesla, problems tend to be exaggerated. With minus 25 the Performance might not perform well, but that is extreme and I don’t think these extremes should be put out there as the norm.

I do not think it need to be -25 to get into low power. Maybe it need to be quite cold to get such low power that it limits highway driving.

For me, living far north(approx. polar circle ) I need to use spike winter tyres during 6 month each year and these do not take a lot of high powered driving that well( it kill the tyre premature) so I anyway dont need more than ”Chill mode” power during the winter season. It doesnt seem to be a problem for me.
During summer tyre season the battery probably gets hot enough so I guess people wont have any trouble then.

 

[Devils son]

New tests from Bjorn shows the 2021 LR is faster from SoC 40% and lower than the 2021 Performance!

View attachment 636417

Well, mine was faster at 20% SOC than the LR with 90%, on a damp road, no preheating, battery at 12 degrees, ambient temperature just above 0 degrees celcius.

But of course, this will get him more clicks.

 

[eivissa]

Well, mine was faster at 20% SOC than the LR with 90%, on a damp road, no preheating, battery at 12 degrees, ambient temperature just above 0 degrees celcius.

But of course, this will get him more clicks.

We have done some extensive testing and number crunching in the German Forums and Björns numbers match ours both in that the LG LR is surprisingly powerful at low Temps and SoC and that the Performance Refresh is not. His numbers match ours exactly with the turning point being 40%.

No comparison has been done to the Panasonic long range, but no point doing that really as it will be somewhere in the middle.

I think you should provide some measurements from your performance at low SoC (and temperatures if possible) as I doubt that these cars run different software around the globe. The interesting number is actually if yours also limits it's lower voltage to 280V. If so, then I am sure they are all equal(ly low) in power output below 40% SoC.

 

[Devils son]

We have done some extensive testing and number crunching in the German Forums and Björns numbers match ours both in that the LG LR is surprisingly powerful at low Temps and SoC and that the Performance Refresh is not. His numbers match ours exactly with the turning point being 40%.

No comparison has been done to the Panasonic long range, but no point doing that really as it will be somewhere in the middle.

I think you should provide some measurements from your performance at low SoC (and temperatures if possible) as I doubt that these cars run different software around the globe. The interesting number is actually if yours also limits it's lower voltage to 280V. If so, then I am sure they are all equal(ly low) in power output below 40% SoC.

What is your point with extensive testing? I did a run with dragy, 20% soc, battery temp 12 degrees, damp road and got a 4,2 sec. time 0-100, standing start, flat road.

So the MY2021 Performance can still outperform a LR at 20% soc. Period.

 

[emmz0r]

What's worse is that a 2019 LR will outperform a 2021 P in supercharging time. This is personally my biggest concern.

 

[Devils son]

What's worse is that a 2019 LR will outperform a 2021 P in supercharging time. This is personally my biggest concern.

For now, in the cold. Not sure how the performance will be when the temperature rises.

And I am guessing that Tesla now has very restricted settings on the new batteries, bit will release more of the potential later on.

 

[AlanSubie4Life]

The interesting number is actually if yours also limits it's lower voltage to 280V. If so, then I am sure they are all equal(ly low) in power output below 40% SoC.

Why do you say this? Are you saying that at max power where people are having “problems” the voltage is dropping (sagging) to 280V, whereupon higher current draw is prohibited, and that is what is limiting the power output? Seems to me that would take an awful lot of internal resistance unless you were at very low SoC, but I’m not saying you are wrong - just wondering about the supporting data for this claim.

By itself, of course, 280V wouldn’t really limit power much at all, as long as 250HP (or whatever is deemed good enough) was “sufficient” and you could still draw 700A at 280V after droop. Certainly power would be much more limited than it is at 400V, but I mean in the context of this discussion - people are throwing around very low power numbers.

What is your point with extensive testing? I did a run with dragy, 20% soc, battery temp 12 degrees, damp road and got a 4,2 sec. time 0-100, standing start, flat road.

So the MY2021 Performance can still outperform a LR at 20% soc. Period.

To be fair, you only hit peak HP around 45mph or so, so there isn’t necessarily a direct relationship between peak power and 0-~60mph (0-100kph) time (though of course under normal conditions there is with these vehicles since peak HP and Max torque are tightly correlated (usually peak HP is the peak torque*RPM at ~45mph)). Anyway: It’s possible to both have lower peak power AND a faster 0-60 time, if you have much higher torque from 0-35mph than the LR (which you do). I am not saying that is exactly the case here - my guess is you probably do have peak HP exceeding the LR - but would have to go through the numbers side by side to really know.

My point: For this discussion, seeing how the 60-80mph times compare would be more relevant, since you’re on the flattish part of the HP curve there, which is much more directly related to your peak HP.

 

[AAKEE]

Why do you say this? Are you saying that at max power where people are having “problems” the voltage is dropping (sagging) to 280V, whereupon higher current draw is prohibited, and that is what is limiting the power output? Seems to me that would take an awful lot of internal resistance unless you were at very low SoC, but I’m not saying you are wrong - just wondering about the supporting data for this

The other way around. Tesla has put a limit to the power draw at low SOC/low temps. Either you limit the Ahmps, or you limit the lowest allovable voltage during load. The limit causes the voltage to not drop as far as it otherwise would.

-At low SOC / cold battery and full throttle the battery voltage is higher than at higher SOC’s on the M3P 2021. Normally it should be lower the lower the SOC.
-The more power you use, the more the voltage drop( The physical law, due to internal resistance).

In this case the lowest voltage during WOT at low soc is higher than with higher SOC.
This tell us that it is not the battery not being able to deliver( internal resistance not the limit), If it was, the voltage would have droped to a value lower than with higher SOC. This we know from the data we have seen. Either Tesla need more experience before unleashing the power or the new low cobolt cells are sensitive and they protect the cells from ”us”.

I did see this for my self, and I actually took some screen dumps but I think i deleted most of them. Maybe have a few left.

Look at teslabjörns tests, and pay attention to the battery voltage drops during the acceleration tests:

Theres no doubt about its a mankind induced limit, and not the battery not being up to to task.

Eivissa probably means that when/if Tesla lowers the battery minimum voltage during load to the same as the old Performance, we will se it drop to 280V instead of 295-ish as we see now. A higher drop at the same SOC means more power.

 

[AlanSubie4Life]

In this case the lowest voltage during WOT at low soc is higher than with higher SOC.

I see, I think. Yeah, that all makes sense. If this is happening on the same vehicle that does suggest they are concerned about how much current to draw from the cell at low SoC, for whatever reason. And that sort of behavior (keeping voltage under load higher at low SoC than they do at higher SoC) would lead to a pretty rapid drop off in power!

Thanks.

 

[eivissa]

And that sort of behavior (keeping voltage under load higher at low SoC than they do at higher SoC) would lead to a pretty rapid drop off in power!

Yes. That is the part I am referring to. My performance refresh would not drop below 280V in any circumstance on the 4000km I have done in it so far. In Björns runs the difference is even higher. 295V vs 268V.

 

[Devils son]

So most likely it is a temporary protection of the battery.