Pack Performance and Launch Mode Limits

[llavalle]

[...]
In fact, they do this when the P cars are in sport mode. I guess I should say PxxDL cars, since I haven't actually measured a non-Ludicrous car.

Right. Wasn't aware of that but that makes sense since the car runs at lower than max amp in Sport mode. Fun fact : my 85D has a non-ludi upgraded P85D pack (came like that from the factory). The BMS is configured to limit at 1150amps but the pack as a 1300amp fuse. I suspect the 85D can be almost as quick as a P85D (non ludi upgraded) but they nerfed the non-P cars to upsell the Ps.

sorry, no cats pics for you guys

 

[TIppy]

Right. Wasn't aware of that but that makes sense since the car runs at lower than max amp in Sport mode. Fun fact : my 85D has a non-ludi upgraded P85D pack (came like that from the factory). The BMS is configured to limit at 1150amps but the pack as a 1300amp fuse. I suspect the 85D can be almost as quick as a P85D (non ludi upgraded) but they nerfed the non-P cars to upsell the Ps.

sorry, no cats pics for you guys

When the 60D and 85D first came out, I read an article that said they had 140 kw(188 hp) motors front and rear. That gave 376 hp total. The original rear motor in the two wheel drive was 283 kw (380 hp). The single rear motor in the P85 was 350 kw (470 hp). Although the two variants of the non-P cars have similar hp, the P85 has considerably more. The P85D added a small performance motor, 165 kw (221 hp), up front.
The small and large motors come in two variant, base and performance.

This is what the service manual says about the current base and performance motors:
small:
base 145 kw
performance 193 kw
large:
base: 285 kw
performance 375 kw

 

[Skysurfer]

The first peak is around 465 kw and the second is 490 kw. Was this with and without max battery ready?

Correct, the first was just Max Battery ready from a stop and the next was Launch Mode.

 

[llavalle]

When the 60D and 85D first came out, I read an article that said they had 140 kw(188 hp) motors front and rear. That gave 376 hp total. The original rear motor in the two wheel drive was 283 kw (380 hp). The single rear motor in the P85 was 350 kw (470 hp). Although the two variants of the non-P cars have similar hp, the P85 has considerably more. The P85D added a small performance motor, 165 kw (221 hp), up front.
The small and large motors come in two variant, base and performance.

This is what the service manual says about the current base and performance motors:
small:
base 145 kw
performance 193 kw
large:
base: 285 kw
performance 375 kw

They did increase the performance of both the "non-performance" small motors. When I got the car, I had a 0-100kph of around 5.6sec. Then an OTA came out and I had a slider to select "normal" or "sport" mode in the driving tab. In sport mode, I had a 0-100kph in the middle 4 seconds (around 4.5sec). Then another OTA came out and the option was removed - car was always in sport mode.

The 145kW number is cleary weird though because when I run the car in RWD mode , it pulls almost 250kW...

 

[TIppy]

They did increase the performance of both the "non-performance" small motors. When I got the car, I had a 0-100kph of around 5.6sec. Then an OTA came out and I had a slider to select "normal" or "sport" mode in the driving tab. In sport mode, I had a 0-100kph in the middle 4 seconds (around 4.5sec). Then another OTA came out and the option was removed - car was always in sport mode.

The 145kW number is cleary weird though because when I run the car in RWD mode , it pulls almost 250kW...

250 kw from the battery would be about 200 kw at the motor shaft. I guess that's close to the 193 kw for the small performance motors. Those are supposedly only for the front motors on the P cars. Didn't know there was a rear motor only mode on the D cars.

 

[llavalle]

250 kw from the battery would be about 200 kw at the motor shaft. I guess that's close to the 193 kw for the small performance motors. Those are supposedly only for the front motors on the P cars. Didn't know there was a rear motor only mode on the D cars.

I'll need to do some more tests and film the whole thing. To run RWD or FWD, you need factory mode access.

 

[TIppy]

I'll need to do some more tests and film the whole thing. To run RWD or FWD, you need factory mode access.

Try both RWD and FWD. Perhaps over time they have started using the small performance motor on the rear, or possibly front and rear. Seems like an unnecessary expense since they don't make use of the performance.
I think this is the article:
Five Things To Know About The New Tesla Model S 60D, 85D and P85D Electric Sedans
That was 2014. Things could be different now.

 

[llavalle]

Try both RWD and FWD. Perhaps over time they have started using the small performance motor on the rear, or possibly front and rear. Seems like an unnecessary expense since they don't make use of the performance.
I think this is the article:
Five Things To Know About The New Tesla Model S 60D, 85D and P85D Electric Sedans
That was 2014. Things could be different now.

I have a 2015 85D that was built in Feb 2015 - one of the first non-P dual motor car off the line.

I'll take the measurements later but just for fun, I remember I took a screenshot of the CAN screen with a bunch of signals selected for decode.

Pack was at 390V so around 90% SOC.

You can see that the car reports a maxDichangePower of the pack of 316kW (pack was cold - see 2nd screenshot)
It also reports a max power of the rear drive inverter (DI) of 316kW. This one pretty much follows the max BMS.
Then reports a max power of the front drive inverter, secondary/slave (DIS) of 297kW : makes sense since wiring to the front DI is smaller and longer.

Thermal screen :

edit : found another one I took while driving :
Car was at highway speed, in range mode so 100% front wheel drive.
Remember DI = rear, DIS = front

 

[n2mb_racing]

I have a 2015 85D that was built in Feb 2015 - one of the first non-P dual motor car off the line.

I'll take the measurements later but just for fun, I remember I took a screenshot of the CAN screen with a bunch of signals selected for decode.

Pack was at 390V so around 90% SOC.

You can see that the car reports a maxDichangePower of the pack of 316kW (pack was cold - see 2nd screenshot)
It also reports a max power of the rear drive inverter (DI) of 316kW. This one pretty much follows the max BMS.
Then reports a max power of the front drive inverter, secondary/slave (DIS) of 297kW : makes sense since wiring to the front DI is smaller and longer.
View attachment 239298

Thermal screen :
View attachment 239299

edit : found another one I took while driving :
Car was at highway speed, in range mode so 100% front wheel drive.
Remember DI = rear, DIS = front
View attachment 239301

So, the non-P cars have motors that are capable of over 500 kW? My P90DL doesn't exceed 490 kW. Interesting. So, limited entirely by battery.

 

[llavalle]

So, the non-P cars have motors that are capable of over 500 kW? My P90DL doesn't exceed 490 kW. Interesting. So, limited entirely by battery.

Pretty much yeah. And that battery limit is artificial on non-P cars. Check the 3rd image. BMS_maxDischargeCurrent is 1150amps. My pack has a 1300amp fuse (same as a non-ludi P85D) but the motors won't pull more than 1150 amps because the BMS tells them to.

The Ps do have a the bigger rear drive unit which is capable of more torque at low RPMs but at highway speed, I have a feeling that a 85D that could pull 1300amp would be as quick or quicker than a P85D also limited at 1300amps.

In RWD mode, my car is pretty quick (butt-dyno)... like 85-90% of the kick of it in AWD. Front wheel drive isn't as fast because traction control kicks in.

 

[n2mb_racing]

Pretty much yeah. And that battery limit is artificial on non-P cars. Check the 3rd image. BMS_maxDischargeCurrent is 1150amps. My pack has a 1300amp fuse (same as a non-ludi P85D) but the motors won't pull more than 1150 amps because the BMS tells them to.

The Ps do have a the bigger rear drive unit which is capable of more torque at low RPMs but at highway speed, I have a feeling that a 85D that could pull 1300amp would be as quick or quicker than a P85D also limited at 1300amps.

In RWD mode, my car is pretty quick (butt-dyno)... like 85-90% of the kick of it in AWD. Front wheel drive isn't as fast because traction control kicks in.

Interesting... well, gotta differentiate somehow...

 

[TIppy]

I have a 2015 85D that was built in Feb 2015 - one of the first non-P dual motor car off the line.

I'll take the measurements later but just for fun, I remember I took a screenshot of the CAN screen with a bunch of signals selected for decode.

Pack was at 390V so around 90% SOC.

You can see that the car reports a maxDichangePower of the pack of 316kW (pack was cold - see 2nd screenshot)
It also reports a max power of the rear drive inverter (DI) of 316kW. This one pretty much follows the max BMS.
Then reports a max power of the front drive inverter, secondary/slave (DIS) of 297kW : makes sense since wiring to the front DI is smaller and longer.
View attachment 239298

Thermal screen :
View attachment 239299

edit : found another one I took while driving :
Car was at highway speed, in range mode so 100% front wheel drive.
Remember DI = rear, DIS = front
View attachment 239301

I see that the dis_drivepowermax is down to 250kw in the second screen capture. It was 297 kw in the first. Probably because it's a little warmer since you're driving 28 kw through it. These max powers are higher than the rated powers of the motors. I remember someone saying that the control firmware for the inverter allows for very brief overpower from the motors. This is in line with the already 50 kw lower max that the front motor has because it's warmer. Can you do some zero to sixty runs and monitor the canbus for current and voltage at max power? Separately for front and rear motors would be great.

 

[llavalle]

I see that the dis_drivepowermax is down to 250kw in the second screen capture. It was 297 kw in the first. Probably because it's a little warmer since you're driving 28 kw through it. These max powers are much higher than the rated powers of the motors. I remember someone saying that the control firmware for the inverter allows for very brief overpower from the motors. This is in line with the already 50 kw lower max that the front motor has because it's warmer. Can you do some zero to sixty runs and monitor the canbus for current and voltage at max power? Separately for front and rear motors would be great.

"dis max power" was down because the voltage of the pack was lower. It not the "available power", it's the max.

The hard limit is amps though the wiring so as the pack's voltage goes down, so does max power of both motors. The pack was at 359V while pulling ~95A. I don't have another picture to show the SOC % but let's assume a 5V voltage drop @ 95amps, it was around 364V or around 60%.

I think I might already have posted that here, but just in case, here's a quarter mile video with CAN info overlaid on top of it (info is at bms info is at 100Hz) on my 85D.

I'll capture the CAN while playing with FWD and RWD mode for sure

 

[n2mb_racing]

"dis max power" was down because the voltage of the pack was lower. It not the "available power", it's the max.

The hard limit is amps though the wiring so as the pack's voltage goes down, so does max power of both motors. The pack was at 359V while pulling ~95A. I don't have another picture to show the SOC % but let's assume a 5V voltage drop @ 95amps, it was around 364V or around 60%.

I think I might already have posted that here, but just in case, here's a quarter mile video with CAN info overlaid on top of it (info is at bms info is at 100Hz) on my 85D.

I'll capture the CAN while playing with FWD and RWD mode for sure

That's cool. How'd you overlay the CAN data?

 

[TIppy]

"dis max power" was down because the voltage of the pack was lower. It not the "available power", it's the max.

bms_maxdischargepower is still at 337 kw. The internal resistance of your battery is about 0.06 ohms. At 95 amps that's about 6 volts, so the unloaded pack voltage is about 365 volts. (365 - 0.06 * 1150) * 1150 is 340 kw. There's still plenty of power available from the pack to drive the front motor at 300 kw if it would accept it. I would assume that drive power max would be exactly that. The max power the drive(inverter) can provide. The rear motor still says 325 kw max. That's nearly the power of the large rear motor. If these motors could handle 325 kw, they would be 351 hp each, or 702 motor shaft hp total. I really don't think that is possible.

Maybe you got more than just a P85D insane mode battery.

 

[llavalle]

That's cool. How'd you overlay the CAN data?

Free tool call Dashware. Converted my CAN to a CSV file are created a mapping for this custom CSV in the tool. Then it was a matter of aligning the data with the video. Took like 30min tops.

bms_maxdischargepower is still at 337 kw. The internal resistance of your battery is about 0.06 ohms. At 95 amps that's about 6 volts, so the unloaded pack voltage is about 365 volts. (365 - 0.06 * 1150) * 1150 is 340 kw. There's still plenty of power available from the pack to drive the front motor at 300 kw if it would accept it. I would assume that drive power max would be exactly that. The max power the drive(inverter) can provide. The rear motor still says 325 kw max. That's nearly the power of the large rear motor. If these motors could handle 316 kw, they would be 340 hp each, or 680 motor shaft hp total. I really don't think that is possible.

Maybe you got more than just a P85D insane mode battery.

I guess we're saying the same thing. What I mean by "it's the max, not available", is that under heavy acceleration, this number doesn't go down significantly. In "drive", at 0 kph, it might say 325kW. Floor it and it'll go down to 315 or 305. Its not like it's "total power available MINUS total power currently in use". It's the total, regardless of how much amps you're currently pulling.

You should read it that way : "under normal conditions, the front drive inverter is unable to pull more than X kW". As the SOC of the pack goes down, so does this value. The whole thing is hard to convey in text form, seeing a video helps a lot.

What's odd is that the front DI values does go down in a linear way with voltage but the rear du doesn't. We don't have the whole picture.

 

[TIppy]

Free tool call Dashware. Converted my CAN to a CSV file are created a mapping for this custom CSV in the tool. Then it was a matter of aligning the data with the video. Took like 30min tops.



I guess we're saying the same thing. What I mean by "it's the max, not available", is that under heavy acceleration, this number doesn't go down significantly. In "drive", at 0 kph, it might say 325kW. Floor it and it'll go down to 315 or 305. Its not like it's "total power available MINUS total power currently in use". It's the total, regardless of how much amps you're currently pulling.

You should read it that way : "under normal conditions, the front drive inverter is unable to pull more than X kW". As the SOC of the pack goes down, so does this value. The whole thing is hard to convey in text form, seeing a video helps a lot.

What's odd is that the front DI values does go down in a linear way with voltage but the rear du doesn't. We don't have the whole picture.

Under heavy load (1150 amps), the pack can provide 340 kw at the current SOC(60% as you said). Notice that when the pack max power(cold) was 316 kw, that was the limit of the rear motor max drive power. Now that the pack is warm and can supply 340 kw, the rear motor is limited to 325 kw. So that seems to be the upper limit for the motor. I believe this is the very brief peak power, not the rated power of the motor.

 

[llavalle]

Under heavy load (1150 amps), the pack can provide 340 kw at the current SOC(60% as you said). Notice that when the pack max power(cold) was 316 kw, that was the limit of the rear motor max drive power. Now that the pack is warm and can supply 340 kw, the rear motor is limited to 325 kw. So that seems to be the upper limit for the motor. I believe this is the very brief peak power, not the rated power of the motor.

Yup, makes sense. We'll know for sure when I do the tests.

 

[TIppy]

Yup, makes sense. We'll know for sure when I do the tests.

It would be good to log the torques to both motors to make sure it's completely RWD and not just mostly RWD.

 

[llavalle]

It would be good to log the torques to both motors to make sure it's completely RWD and not just mostly RWD.

yup, I'll be dumping the whole PT CAN so I'll have motor torque (front and rear), motor amps (front and rear), BMS info (total amps and volts), speed, etc.

I just need a safe place to do that. Close to home I have a highway but I can't legally stop by the side to do a 0-100kph run. Everywhere around is max 50kph. I can push it to 65-68 but over that and I'll get pulled over and I can tell you everyone around my house knows exactly who owns the "white Tesla"