Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register
  • We just completed a significant update, but we still have some fixes and adjustments to make, so please bear with us for the time being. Cheers!

Has anyone tested the decline of power on the P3 with the decline in total battery?

Electric Dream

Pilots the Millennium Milkfloat
Jul 21, 2016
1,593
2,671
UK
Feel...number of people I pass and the ease at which I pass them. 2 track days with same results. Ambient temp probably around 90. I don't have any data to back it up but I'm 100% confident power is down quite a bit below 20%....30 may be too high. Below 10% the car is a complete dog.
Could be temperature dependent?
I was lapping at 10% in an ambient temperature of 62F and no noticeable difference. Even in track mode with better temperature control, maybe it struggles over a certain temperature?
 
  • Like
Reactions: destructure00

Adam3

Member
Oct 4, 2015
730
950
USA
This was posted to reddit today

PhSAgGt.png
 
  • Informative
Reactions: destructure00

MagnusMako

Member
Jan 29, 2019
705
1,205
Austin, TX
It is a well known fact that power decreases as SoC lowers. There should be other threads on this on these forums.

Youtuber DamienG did thorough acceleration testing at various SoC levels with his P3. LINK

SoC.png
 

ElectricOrgan

Member
Oct 11, 2019
131
-29
USA
There's some good information and test results in this thread: P3D+ Acceleration

My experience on track suggess the P3D+ in track mode performs in a very similar way from 90% all the way to 10% at least. Looking at data I logged last time I tracked it, there was very little difference in top speeds at the end of the fastest straight (2-3mph tops) between 80% and 10%.

The voltage curve for most battery types is sharp near 100% and near 0%. In the middle it is flatter. I've never heard of a difference in internal resistance which is the parameter that would limit current. So the major impact to power from the battery state of charge is the voltage change near the ends. Of course the temperature of the battery makes a larger difference I believe. That's why they heat the battery in performance+ mode.
 

ElectricOrgan

Member
Oct 11, 2019
131
-29
USA
It is a well known fact that power decreases as SoC lowers. There should be other threads on this on these forums.

Youtuber DamienG did thorough acceleration testing at various SoC levels with his P3. LINK

View attachment 472912

These numbers make pretty good sense. The 0-60 times are all on the part of the power curve that is limited by the motor torque rather than the battery power. That is, the motor output is torque limited rather than power limited. I can't explain the large change at 30% SOC, but the rest are small or zero until getting down to 10% SOC.

The 0-100 mph is controlled much more by the other part of the power curve where the power limit very much depends on the SOC of the battery and so most of the deltas are at the high and low ends. Not sure why the 100 vs. 90% SOC points are only 1.5% different, but there may be something special about 100% SOC that impacts that.
 

Electric Dream

Pilots the Millennium Milkfloat
Jul 21, 2016
1,593
2,671
UK
I did some 0-60 runs today at low SoC (10-20%). There are some differences I can see from the data I logged between using Sport mode and Track mode (P3D+).

In Track mode, the acceleration and speed traces look to be much smoother, whereas in track mode there are more spikes, particularly at launch. The data is showing slightly harder initial launches in Track mode.

I've seen some reports from those who have tried both on the dragstrip and don't think there's a difference, but I believe there is, albeit a subtle one which won't always show up in time/speed measurements alone.

It needs more research, but I feel there are benefits to be had using Track mode for 0-60 runs and at low SoC generally if you want to extract the most performance regardless of whether you are on the dragstrip or a circuit. Of course, everyone who is taking their Model 3 to a track is going to want the highest SoC anyway, but it's nice to know what's going on and there may be benefits to be had at much higher SoCs in any case.

I've looked at a number of 0-60/0-100 results on various forums and it's often not stated whether the runs have been in Track mode or not. I suspect most people testing on the street have been using Sport mode.

When SoC is low and the dots appear on the right end of the power meter, I have seen a couple of times that the power is has been limited less when I've been in track mode at the same SoC as when I've been in Sport mode. This again might account for some people saying the car is a slow dog at <20% when I felt it was doing pretty well withTrack mode on at 10% recently.

Now I've got data from the Scanmytesla app as well as from other loggers, it gives me a lot more to go on besides 'feel' so I'll be looking more closely at the power and torque numbers at various SoC and different modes to see what's going on.
 

MagnusMako

Member
Jan 29, 2019
705
1,205
Austin, TX
Interesting data. Hard to explain some of the variations.

Thread below is some actual dyno testing that MountainPass performance just did with the P3D showing the true hp drops at various SoC levels. Below 75% there is a significant drop off. Due to voltage sag the inverter is cutting back power to protect the battery. From 95-100% is moot, with maybe 1-2 hp difference.

Vendor - Model 3 Performance Dyno Test: Binned Motors?

Video from said thread:

 

Nocturnal

Supporting Member
Aug 23, 2018
6,054
30,078
In the middle
My own track experience showed a small, but consistent drop in ET as I moved from 92% SOC down to mid 80s. Something to worry about if you are racing it, but nothing to worry about in normal spirited driving.
 

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top