Jul 31, 2016
JRP3 Understood, I was really only commenting on his particular situation, and that his range seems to have increased to very near what it should be. I fully agree that those of you with much greater losses actually have a strong case against Tesla and that they should actively be addressing the problem. They have no excuse not to do so.�
Jul 31, 2016
msnow Agree and I also never have heard anything authoritative (other than speculation) about the reserve anti-brick kWh.�
Jul 31, 2016
ArtInCT Yah, the so called "anti-bricking" buffer is a debatable topic. Without an authoritative white paper from Tesla, we can only wonder if it really exists. I for one am very skeptical about bringing my traction batter to near zero or near 100%. I have been to 95% only once in fact and that was on a 4 day spoke trip off of the main Supercharger routes up in Maine. We charged to 95% at a SuperCharger in Augusta, ME and then headed to Camden, ME for 4 days. I did not look ahead well enough to be frank. Me bad. There was an Inn that we could have stayed at which had a Tesla HPWC. They were part of the "destination" charging program. I learned from this to look for such places before making reservations. None the less, this is where the large battery shines and takes the anxiety out of the equation. I just could not see myself with a 60 kWh battery, especially in the winter where range is really pessimistic.�
Jul 31, 2016
Boatguy The procedure is very simple. On some reasonably long trip, say at least 40-50mi, reset your Trip A and note the starting RM. When you arrive, divide the kWh used by the RM consumed. Repeat that 4-5 times and you'll find the values for Wh/RM cluster within a couple of Wh.
At least on my car, Tesla uses 290Wh/RM for the Projected Miles calculation on the Energy display, which is quite misleading when they tick off an RM every 273Wh.�
Jul 31, 2016
Boatguy I don't think there is any question that the buffer exists. BMW is quite explicit about the battery in the i3. The car has a 22kWh battery, of which only 19kWh is available for driving. That's 13% of total battery capacity which is pretty high.
My S90D loses one RM every 273Wh. At delivery the 100% was 294RM. So 294RM * 273Wh/RM = 80.2kWh. Assuming the battery is actually 90kWh, then the "anti brick" or whatever we want to call it, is about 10kWh.�
Jul 31, 2016
lolder The Whr/mile is very dependent on speed. If you drive slowly it goes way down. If you drive 80 it will probably be over 350.�
Jul 31, 2016
Boatguy That's true for Wh / odometer mile, it's not true for Wh / Rated Mile.�
Jul 31, 2016
apacheguy For my 85, this number appears to be right around 300 Wh/mi�
Aug 5, 2016
mspisars I think that we need to define "substantially less range" then, because based on his chart he is 2 miles short of 90% (that is 0.778 % difference) and 3 miles short of 100%
Also, I'm with @JRP3
�
Aug 5, 2016
msnow Because you missed the point. For 9 of those 10 months he wasn't getting near that so he didn't get the benefit of his $3k. Read his log file, in the first few weeks he lost 3% or 8 of his promised 16 miles. That was very, very fast and he was better than most. If you've been following this thread you will see most lost about 5% in 8 weeks while waiting for the promised fix which still hasn't materialized.�
Aug 5, 2016
mspisars What I see from the log is it started 2 miles short and ended 2 miles short of 90%...�
Aug 5, 2016
ArtInCT Thanks for that procedure:
I have been logging my trips since then.
294, 276, 300, 302, 294, 300 are the resultant factors.
The longer trips settle in at 300 as the factor.
The shorter trips as you can see are all over and usually lower.
Most of my shorter trips are 35 MPH back roads, the longer trips being 65 MPH highway cruising.
Yesterday, on a 120 Mile trip it was dead nuts on 300 as the resultant factor.
So for the P90D in this type of weather (80F with air on) I can use the 300 as my factor.
Art�
Aug 5, 2016
Pale Hearse Yes Mike.. but.. as I pointed out..
How that range is calculated.. i.e. the only way the car actually has to make that calculation.. is to take the amount of charge at mile segments and then make a calculation over a given distance to show a number. This number is a calculation based largely on the system's "experience". There are MANY examples of this on Youtube that highlight this. This is the reason that if you habitually charge to 80% and then suddenly charge to 100% a couple times and deplete to 10-20% ish.. that number changes.
If this were purely based on the power.. that wouldn't be the case. The idea is that the car is smarter than that and it's designed not to be "wrong" for any individual driver.
I usually drive mine around like a lunatic. I'm here in CA where superchargers are everywhere and I have lots of charging options both at home and at my many destinations. Because of this, I basically drive it like a Ferrari.
As a result, my max range decreased. My father came for a visit and I spent a long weekend following him around in his Prius. As I did so, around day 2, I noticed something curious happen. I would drive for many miles near the 70% mark and notice that my estimated miles seemed to be having difficulty. When I initially picked up the car, it showed 288 miles at full charge. Prior to my father's visit, it was down to around 272 at about 12K miles. After he left... it was at 278-280. And now? Well it's back to 272-275 at 37,000 miles now.
Probably time to try this again.
My initial mistake was not recording the "ideal" miles when I got the car new. Any new 90D owners care to share what their cars are showing as the ideal miles?�
Aug 5, 2016
msnow Rated Range is NOT based on your driving style. Driving it like a Ferrari or a Prius won't impact the algorithm used to calculate RR. Driving style will impact "Estimated Range" only. Charging style will affect the displayed range until you balance/calibrate the pack. EPA Rated Range is a 5 stage test based on many factors so if you drive using the metrics they use such as ideal temperature, combination city and highway, ideal speed, etc, etc, you can achieve the EPA rating until or unless the battery degrades.�
Aug 5, 2016
Pale Hearse We disagree... not sure where you are getting your information from.. but what you describe does not jive with my experiences and the experiences of others.
The calculation seems to be at least partially based on the rate of depletion. As you pointed out, however, it is based on the car's "experience" with the battery. If it wasn't then there would be no need to calibrate at all. It would simply use the amount of energy stored in the battery to make the calculation. So what you are saying doesn't pass the sniff test.
Their is not AI involved here.. just calculation. What you are saying is that the depletion rate is a fixed amount. Say 300wh per mile.. or some other arbitrary figure. What I believe to be the truth is that the car has the ability to "fudge" this number over time to more accurately project the rated number. Otherwise.. it wouldn't change.
I agree that the lion's share of the calculation is based on the amount of energy put into the battery.. but there again.. it's depletion isn't evenly distributed.
For example.. charge your car to 100%. Then drive one mile.. and look at your range. If you charged to 180 at a full charge.. by the end of one mile I can guarantee you it will be about 176. By your reasoning.. why would that be?
In the account I gave.. that was equally true.. but.. it also sat there at freeway speeds and I watched it.. consuming 290-310wh per mile. It got to about 210-212.. and sat there.. for about 15 miles before starting to once again follow counting the miles more or less appropriately.
So no.. there is more to that calculation I think. So unless you are getting this information straight from the programmer.. it doesn't seem to fit the real world model of how the rated mileage is displayed.
If you said you were talking about the ideal number.. then you would have an argument... and that was my point all along. I am kicking myself for not looking at what the ideal range was when I first got the car. That number.. changes with the total amount of energy in the battery registered by the car.�
Aug 6, 2016
msnow Over time and a little research you will see that is not correct. EPA is in fact a fixed tested number, it doesn't change. The EPA RR number displayed on your instrument cluster will change when the algorithm gets confused by charging habits or real battery degradation. If you bought an ICE car and the sticker said it had an EPA rating of 30 MPG that rating isn't going to change based on the way you drive but your ability to achieve or exceed it will. What you're talking about is the Estmated Range on the Energy App which is based on your past 5/15/30 miles of driving experience. Hope that makes sense.�
Aug 6, 2016
cinergi I'm consistently now hitting 255 at 90%.
BTW there are threads covering what rated range as displayed by the car is. It is not purely based on energy in the pack; it does include driver behavior as well as environmental factors. There's not only plenty of evidence to support this but I have it straight from Tesla engineering's (not sales or service) mouth.�
Aug 6, 2016
msnow Upthread we have written documentation from work orders as to the cause of this problem. EPA is EPA. What do you have? You and the previous poster refer to links and "YouTube videos" let's see it.�
Aug 6, 2016
hiroshiy While I agree that mostly RR is EPA, but there are some things that affect the fixed number, be that temperature and driving style. I thought @jerry33 recorded every day 90% charge RR numbers for a few years now and his data clearly showed some seasonal trends.
That said after D models are introduced RR number seems to be too low, 273Wh. Previously Classic cars had 300. And European/Japanese Classic as 320, so my Classic had only 246 miles RR at delivery. It seems Euro/Japanese D models have something like 290.�
Aug 6, 2016
msnow Yes, I have also seen evidence that temperature can affect it temporarily but not driving style. Coincidentally I was at the Service Center today and I talked to both the Service Manager and Shop Forman while I was waiting for a firmware update and both said how you drive as zero to do with any variation of Rated Range. They also said many people confuse Rated Range, Estimated Range and Ideal Range. Tesla should put out a white paper on this so there isn't so much confusion.
@hiroshiy all of the 90D's since at least March/April of this year are getting 294-296 at 100%. The battery part number also changed from my version.�
Aug 6, 2016
apacheguy We have it from @wk057 that the rated range calculation is simply pack capcity divided by a constant. For my pack that constant is ~302 Wh/mi�
Aug 6, 2016
TexasEV The definition of rated range is the range on the EPA test cycle. Period. Full stop. The rated range that is displayed may vary at times because it's not possible to calculate the state of charge of the battery exactly, but that doesn't change the actual rated range. If anyone has written documentation from an authoritative source that says otherwise, please share it. What someone heard from someone doesn't qualify.�
Aug 6, 2016
hiroshiy Thanks, @msnow for further explanation.
BTW I didn't include units so my post wasn't clear enough. I wanted to mention the RR constant is different from models and vintage:
"after D models are introduced RR constant number seems to be too lower, 273Wh/mile. Previously Classic cars had 300Wh/mile. And European/Japanese Classic as 320Wh/mile, so my Classic had only 246 miles RR at delivery, @320Wh/mile, so equivalent to 262 miles of RR. It seems Euro/Japanese D models have something like 290Wh/mile, even though PD models consume more energy than Classic RWD models, so it is harder with PD models to reach RR than with Classic RWDs.�
Aug 6, 2016
Boatguy I think the Tesla personnel confused Estimated Range with Projected Range. And I agree that a Tesla white paper would be useful. I think I've basically reverse engineered what's happening with RM vs Projected Miles.
The displayed RM is battery capacity available for driving divided by a constant. In the case of the S90D, that constant is 273 Wh/RM.
Projected Miles is an adjustment to RM based on driving style/conditions for the last 5/15/30 miles (or the appropriate km). However, for reasons known only to Tesla, on my S90D the constant used is 290Wh/mi. So for example if your consumption over the last 30 miles was 310 Wh/mi, then Projected miles will be 290/310 = 6.5% less than RM. It's an essentially useless number since it doesn't use the same 273 Wh/mi as is used to calculate the displayed RM.
Ideal Range is some marketing fantasy land that I believe is of no use to an owner.
Seasonally could affect RM by changing available battery capacity. Cold weather does reduce available battery capacity and I see this in my i3 each year, so I would not be surprised to see Tesla RM reduced in winter, but obviously a function of how cold it is where you live. Worse in Finland than Santa Monica!�
Aug 6, 2016
Mike Tuccelli FYI. 10,500 miles .... Stopped charging to 90% at 5,000 miles, charging to 80% and get 282 mile range projection. Steady at 282 for the past 6 months. I'm happy.�
Aug 6, 2016
Boatguy Just to clarify, you get 282 rated miles @ 80% charge? That translates to 352 RM at 100%. I think that's a record and certainly a good reason to be happy!�
Aug 6, 2016
msnow I think he means he "projects" 282 RM at 100% which is about normal for a 2015 90D. It also means 253 at 90% and 225 at 80%.�
Aug 7, 2016
Boatguy Ah yes, I missed the word "projection". Thanks!�
Aug 7, 2016
Pale Hearse
That matches up with my own experience on the matter as well.�
Không có nhận xét nào:
Đăng nhận xét