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2014 Model S range question

Hi, I am a new owner of a 2014 Model S 85, and today for the first time I took it out on a fairly long drive. I charged it fully, and the range listed was 248mi. I drove for 122 miles, and the average Wh/mi listed in the Trips screen was 315 for the whole drive, below but very close to the rated 319 Wh/mi that I have read is used for the range display (I have it set to display rated range, not ideal range). After that drive, I had only 108 miles of range, or 41%. I understand the trip calculation of average Wh/mi includes everything that used power, including climate control. What happened with the other 18 miles? That's a 15% discrepancy, at the rated power consumption. Software is 10.2 if that matters. Thanks for any insight!
 
Hi, I am a new owner of a 2014 Model S 85, and today for the first time I took it out on a fairly long drive. I charged it fully, and the range listed was 248mi. I drove for 122 miles, and the average Wh/mi listed in the Trips screen was 315 for the whole drive, below but very close to the rated 319 Wh/mi that I have read is used for the range display (I have it set to display rated range, not ideal range). After that drive, I had only 108 miles of range, or 41%. I understand the trip calculation of average Wh/mi includes everything that used power, including climate control. What happened with the other 18 miles? That's a 15% discrepancy, at the rated power consumption. Software is 10.2 if that matters. Thanks for any insight!

I drive a December 2014 model s. The rated range is 300 Wh per mile. That may be the calculation issue there, although that would actually seem backwards.

it can take a lot of power if it's cold out, and specially if your car was sitting out in the cold. The battery itself is constantly warmed until it gets to the right temperature. That takes a lot of power! I usually park in the garage but we're remodeling and I've had to park outside. It really makes a huge difference that the battery is so cold when I start. I try to warm it up for at least an hour ahead of time, that does seem to help.
 
My understanding is the "rating" comes from EPA rated range for the car model (2014 Model S 85, 2014 Tesla Model S (85 kW-hr battery pack)) not from anything having to do with my particular car or driving or power consumption. I understand that my battery may not hold a full 85KWh any longer, which I why when full I get only 248 mi rated range. But 85KWh/265mi = 320 Wh/mi. Can anyone give a citation for either 279Wh/mi or 300Wh/mi?
 

Rocky_H

Well-Known Member
Feb 19, 2015
7,851
9,882
Boise, ID
Not talking about rated range but kilowatt per mile. I'll check mine when I go for a drive, I was pretty sure it was 300.
I know what you're probably thinking of. If you are looking at the energy app on the screen, and it shows that line graph of how the energy usage has been for the last 5, 15, or 30 miles is, there are horizontal lines across it at several places, and one of those is at 300, and over at the right, there is this little fine print that says "rated". That has fooled a lot of other people too. That line at 300 has always had that little word next to it for all of the versions of the Model S and X, but they all have slightly different efficiency constants, so that can't be right for all of them, but it's close. The Model S 60 is different from the S 85 is different from the S 100 is different from the P90D version, which is different from the Model X 100D, etc. etc. etc. I said 278 wh / mile, which was calculated pretty closely for the original S 85 versions, but that will shift some with other models.
 
Ok, I see my mistaked -- 300 Wh/mi does seem to be the number used for rated range, based on the car itself (see attached shot of the energy graph from the center screen -- the dotted "average" consumption is just below the solid "Rated" line at 299Wh/mi average). This means that my battery, when full, holds, according to the dash 248mi *300Wh/mi = 74.4KW. Ok, I can believe that, 7 years old with 57k miles. My trip tooks 122 mi * 315Wh/mi = 38.4KW, leaving 74.4KW - 38.4KW = 36KW. That should leave 120 miles of range, and the car showed 108. I guess that's "close enough". The car lost some charge through just sitting during the day, which probably accounts for 3-4 miles, and that gets us within 3% or so.
 

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Ok, I see my mistaked -- 300 Wh/mi does seem to be the number used for rated range, based on the car itself (see attached shot of the energy graph from the center screen -- the dotted "average" consumption is just below the solid "Rated" line at 299Wh/mi average). This means that my battery, when full, holds, according to the dash 248mi *300Wh/mi = 74.4KW. Ok, I can believe that, 7 years old with 57k miles. My trip tooks 122 mi * 315Wh/mi = 38.4KW, leaving 74.4KW - 38.4KW = 36KW. That should leave 120 miles of range, and the car showed 108. I guess that's "close enough". The car lost some charge through just sitting during the day, which probably accounts for 3-4 miles, and that gets us within 3% or so.

Rated range is, well, not real. I've put over 200,000 miles on my car and I can tell you that I've never done better than 320 something for any given set of tires. You do see a difference from one set to another. And more so due to temperature. in any event, I'd figure on 330 as an average for calculating. Actually I've set my battery meter, if you will, to percentage. I just figure I've got twice as many miles as the percentage plus a little buffer, it's much easier than trying to use the miles to empty display.
 
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BigNick

Infamous Fat Sweaty Guy
Dec 3, 2017
1,705
1,876
Pennsylvania, USA
Also note the original "85" battery's capacity was actually something like 81kwh, minus a 4kwh buffer.
I just looked for the actual numbers, but apparently my search skills leave much to be desired. At any rate, the actual usable capacity when new was somewhere around 77 or 78kwh.
"85" = 80.7 kWh
"60" = 61.1 kWh
 
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