Various testers have shown the P85 to get 3.9, so basically (for easy remembering) 5.9--4.9--3.9. Tesla makes the numbers more conservative to avoid complaints (my guess).
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Various testers have shown the P85 to get 3.9, so basically (for easy remembering) 5.9--4.9--3.9. Tesla makes the numbers more conservative to avoid complaints (my guess).
scott jones
Member
That is definitely easier to remember, but my personal opinion is they didn't do it to avoid complaints, but to make the Performance version looks far better for sales.
Otherwise most people wouldn't pony up the Extra $ for a car if they both did in the 4's!
Their only .5 second difference between a much bigger battery (S85 to S60) just never made ANY sense to me the day I saw it.
I was a math minor and new instantly that couldn't be. I don't doubt many P85 customers also got faster than the 4.2.
But I think the biggest error/claim Telsa made was the S85 being just slightly faster than the 60, and MUCH slower than the P85.
If someone tests each on the same day, same condition, I would love to see it! Waiting for this rain to clear up, so I can drive Tessy. That's right, no rain for my S85 because the finish spots too easily.
Otherwise most people wouldn't pony up the Extra $ for a car if they both did in the 4's!
Their only .5 second difference between a much bigger battery (S85 to S60) just never made ANY sense to me the day I saw it.
I was a math minor and new instantly that couldn't be. I don't doubt many P85 customers also got faster than the 4.2.
But I think the biggest error/claim Telsa made was the S85 being just slightly faster than the 60, and MUCH slower than the P85.
If someone tests each on the same day, same condition, I would love to see it! Waiting for this rain to clear up, so I can drive Tessy. That's right, no rain for my S85 because the finish spots too easily.
chickensevil
Active Member
Ok, well I tried using VT to capture the data, but for some reason I get a lot of gaps in the driving logs. I was out from around my last update at 12:30 till now driving around and yet have only about 14 miles worth of data 
In any case there is definitely a power difference between 90% SOC and 45% SOC (what I ended with) but I never could get mine to go over 320kW on the meter. It would only go there and then stop. I had to be careful how much I was doing this because traffic was a pain in the butt today... (gotta love I95!!!) In any case the reason for my journey was to obtain a weight measurement for you all as well. so here it is.
That was about 4 hours and 10$ for you guys! hope it is helpful! Their spec sheet has said 4647 for ever. I had a mostly empty car minus my own weight of about 150 pounds (I am rather skinny) and the mobile connector and some other misc stuff. Car was made in March 2014 VIN 33XXX
In any case there is definitely a power difference between 90% SOC and 45% SOC (what I ended with) but I never could get mine to go over 320kW on the meter. It would only go there and then stop. I had to be careful how much I was doing this because traffic was a pain in the butt today... (gotta love I95!!!) In any case the reason for my journey was to obtain a weight measurement for you all as well. so here it is.
That was about 4 hours and 10$ for you guys! hope it is helpful! Their spec sheet has said 4647 for ever. I had a mostly empty car minus my own weight of about 150 pounds (I am rather skinny) and the mobile connector and some other misc stuff. Car was made in March 2014 VIN 33XXX
Hmm. So the question I'm left with now is under what circumstances will the power draw exceed 320 kW in an S85. I charged up to 90% this morning floored it and recorded a 309 kW ceiling, which was sustained for 1 second before falling back down (I.e. Foot off the accelerator).
I'm not convinced that it's a pack/SOC limitation. Reason being that P85s have the same battery and are consistently able to exceed 320 kW under rapid acceleration even at lower SOC.
I'm not convinced that it's a pack/SOC limitation. Reason being that P85s have the same battery and are consistently able to exceed 320 kW under rapid acceleration even at lower SOC.
apacheguy: At what speed? I assume that reading was from the log - what did the display show?
Electrical components are usually current limited. E.g. there may be a max current rating for the battery, inverter, motor etc. The software will then likely limit based on amps, without regard to voltage. That means that you may, depending on how things are wired and programmed, get more power at a higher battery voltage.
Assume some system has a max current of 100 A and a battery consisting of 100 cells in series. At cell voltage = 3.8 V we get 38 kW, at cell voltage = 3.5 we get only 35 kW.
So the fact that the P85 gets more power from the same battery does not mean that the S85 is not affected by battery voltage.
Electrical components are usually current limited. E.g. there may be a max current rating for the battery, inverter, motor etc. The software will then likely limit based on amps, without regard to voltage. That means that you may, depending on how things are wired and programmed, get more power at a higher battery voltage.
Assume some system has a max current of 100 A and a battery consisting of 100 cells in series. At cell voltage = 3.8 V we get 38 kW, at cell voltage = 3.5 we get only 35 kW.
So the fact that the P85 gets more power from the same battery does not mean that the S85 is not affected by battery voltage.
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chickensevil
Active Member
Air Conditioner? I never floored it at hit SOC with the AC on, I don't think...maybe try that.
About the P vs S there is a different inverter. My guess is that the S inverter is capped at (for example) 200A so as the Voltage drops on the pack you get less overall power. The better inverter in the P might be capped at 300A (again example) but now you need to up the electronics on some other part to get even higher performance...
Based on the comments from Elon, the speed and power limitation on the MS is not caused by the batteries. Someone had specifically asked if the performance will improve when they start using new cells in the MS (just as performance improved from the Roadster to the S). If you want the full comments it was in the annual shareholder video.
I see. I was thinking it was a power output limitation. I didn't think about it being tied to the current and not the voltage.
@eledille - I was in the 50-60 mph region when I reached the max output. The dash needle was just a hair short of 320, in line with the value read through the API. A/C was on.
Can anyone confirm power > 320 kW in an S85 at any pack voltage/SOC? chickensevil's post has got me thinking that the answer is no. Prove me wrong.
@eledille - I was in the 50-60 mph region when I reached the max output. The dash needle was just a hair short of 320, in line with the value read through the API. A/C was on.
Can anyone confirm power > 320 kW in an S85 at any pack voltage/SOC? chickensevil's post has got me thinking that the answer is no. Prove me wrong.
chickensevil
Active Member
For clarification my thoughts on the inverter and the limitations on the power output are just guesses, but it makes the most sense for why and how one car is faster than the other... And also explains the performance loss as you go lower on the SOC %. I also know that the voltage is fixed on each cell and is tied to the charge % whereas the current/amps vary depending on how much power you want to pull out at once.
My question is, the charge and discharge rate of the battery is supposed to be capped at a 2C rate, or so I thought... Anything more than that and you are damaging the cells... So if you are pulling 320kW (or more) from an 85kW pack, isn't this WAY over that limit? So if 2C is not the limit, then what is? And does this mean we could see a 320kW supercharger in the future?
My question is, the charge and discharge rate of the battery is supposed to be capped at a 2C rate, or so I thought... Anything more than that and you are damaging the cells... So if you are pulling 320kW (or more) from an 85kW pack, isn't this WAY over that limit? So if 2C is not the limit, then what is? And does this mean we could see a 320kW supercharger in the future?
Just watched that video, and as an aside, was really surprised Musk didn't know what the question was about. The person was just referring to the capacity of the 18650 cell in mAh (though he did state 'milliamps' instead.) Thought Musk would instantly catch on but instead he thought he was talking about power output. Maybe he was super-tired...certainly seemed like it.
doctorwho
Active Member
Wow! The old bezel must have been amazingly heavy
LOL. When the sun is just in the right position, the old bezel is blinding. I wish they'd made it flat black or some other colour rather than silver as I'm pretty sure the new one will still be uncomfortably bright.
The cells tolerate much higher discharge current than charge current.
@apacheguy - when I tested this the other day I did have the AC on, but set at 20 deg C. Outside temp was also 20 degrees C, so it shouldn't have been doing anything.
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There are five marks, 20, 40, 80, 160, 320. Divide the numbers by ten and you have the five first powers of two. Example: The fourth mark has the value 10 * 2[sup]4[/sup] = 160. The midpoint between 320 and 640 is 10 * 2[sup]5.5[/sup], which is 453. One quarter above 320 is 10 * 2[sup]5.25[/sup], which is 381.
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chickensevil
Active Member
*claps* thank you! I knew there was a way, it has just been such a long time since I have used log math. The most I use it for these days is the charting features in Microsoft Office
So then each "tick mark" is 1/6th of the way, so you would want 10 * 2^5.8333333 = ~359.
So that makes what was observered here pretty close to what everyone should be getting in their performance cars:
In any case, I don't think anyone is getting more than 320 on a S85. If someone can prove otherwise I would appreciate either a picture/video or the logs from VT to confirm what you actually peaked out at and then what your VIN is so we can figure out where the delineation is
Do we actually know what the figure shown in the power meter represents? Power delivered from battery? Power output from the drive inverter? Power at motor shaft? Power at the wheels?
I've always assumed that the quoted figure on the Model S specs page (310kW) is motor shaft, since that would be directly comparable to ICE stats. But I'm not aware of any official statement on what the numbers in the instrument cluster actually mean.
I've always assumed that the quoted figure on the Model S specs page (310kW) is motor shaft, since that would be directly comparable to ICE stats. But I'm not aware of any official statement on what the numbers in the instrument cluster actually mean.
It certainly shows the power consumption of both AC and battery heater, so it's not exclusively the drive inverter. *edit* I just checked - I can see the consumption of the power steering. Just switch off AC and turn the wheel left and right while parked, you can easily see the needle twitch. So it's measuring power from the battery.
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I have an S85, and get more than 320kw in certain conditions. Vin in the mid 6k range. Give me a few days, and I'll try to get a pic or video.In any case, I don't think anyone is getting more than 320 on a S85. If someone can prove otherwise I would appreciate either a picture/video or the logs from VT to confirm what you actually peaked out at and then what your VIN is so we can figure out where the delineation is
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