Decreasing rated range.

[mknox]

Not too long ago (after 4.5 came out) my 90% charge went from 231 to now 228/229. Did my first range charge in a long time yesterday at a supercharger and it ended at 258 (and was stuck there for a while before the car stopped charging)... Not thrilled, but in the past couple of days have started charging at 245 volts @ 6 Amps to see if I can get the pack balanced again.

I did my one and only ever Range Charge back in July when the car had a bit over 10,000 miles. It was at 260 miles and saying 3 minutes remaining (it had been stuck at "3 minutes remaining"for about 20 minutes) and I had to unplug and leave. Not sure if I would have got more than 260 if I let it finish, but that's my data point.

 

[Eggplant]

My 90% range dropped from 242 to 236 after a software update. When I asked Tesla about it, they said 236 was normal, and the algorithm had changed. They also told me to keep in mind that rated range changes with temperature and other factors.

If true, it seems like it would be really hard to compare numbers between a few months since conditions are likely to be very different. Could this be a factor in these lower numbers? Just the fact that we are getting into the colder months in NA?

 

[yobigd20]

Could this be a factor in these lower numbers? Just the fact that we are getting into the colder months in NA?

absolutely. there is MUCH variability in their calculations, which as I've mentioned before is an *ALGORITHMIC BEST GUESS* since actual lithium-ion battery capacity is impossible to accurately measure without fully draining the battery and fully charging it (which is BAD to do as that is a full cycle and really speeds up degradation). that's why I think this thread is a joke and a waste of everybody's time. what you think is decreasing rated range is NOT decreasing rated range. it's just variability in the factors used in their rated range GUESSING algorithm. this will fluctuate both up and down every day. could be down 5 miles one day, then up 8 miles the next. a total guesstimate based on dozens of factors that change daily.

 

[Eggplant]

I think I would agree. At best, you could compare a trend of readings under similar conditions. Comparing single charge numbers seems futile.

 

[SFOTurtle]

absolutely. there is MUCH variability in their calculations, which as I've mentioned before is an *ALGORITHMIC BEST GUESS* since actual lithium-ion battery capacity is impossible to accurately measure without fully draining the battery and fully charging it (which is BAD to do as that is a full cycle and really speeds up degradation). that's why I think this thread is a joke and a waste of everybody's time. what you think is decreasing rated range is NOT decreasing rated range. it's just variability in the factors used in their rated range GUESSING algorithm. this will fluctuate both up and down every day. could be down 5 miles one day, then up 8 miles the next. a total guesstimate based on dozens of factors that change daily.

I agree with you that variations are to be expected and not in and of itself a source of concern. But if there are no "ups" to correspond with the "downs" and all of the data points across weather conditions, and with the same firmware version, are trending downward, then that's something I will keep an eye on, meaning loosely keep track of and not lose sleep over. I do check this thread because as a 60 owner, I like to hear from other 60 owners' experiences given how new this car is. I hope others continue to post their experiences because we are all beta testers and no one knows how the 60 curve will look over time. The more data points the better.

I have not seen *any* upward variability in my rated miles in about 8 weeks, i.e., 8 weeks ago I hit 182 rated miles on a 90% SOC and since then, it's only been less little by little. After doing quite a bit of long distance driving and deep cycles and two range charges on a roadtrip to SoCal two weeks ago (in the same weather conditions), I noticed my rated miles dropped by a little more so that I'm at 178 rated miles at 90% SOC at just under 10K miles.

Because my commute is only about 20 miles roundtrip, I'm going to start charging overnight and/or at work at 110/12A or 240/6A for a couple months to see if there is any upward *variability* (just to see if the top number bounces up even if just a little). I don't see any downside in testing this and if I can keep my rated miles at or about the same level, even better. If not, there was no harm in trying. It is painless either way.

 

[mnx]

I agree with you that variations are to be expected and not in and of itself a source of concern. But if there are no "ups" to correspond with the "downs" and all of the data points across weather conditions, and with the same firmware version, are trending downward, then that's something I will keep an eye on, meaning loosely keep track of and not lose sleep over.

Comparing my last 2 range charges, my range did go up. Last time it stopped @ 416km, this time it read 418km when it finished.

We really need access to the diagnostic mode where we can see the CAC of the battery (among all the other interesting stuff like temperatures). Then there would be no guessing if one's battery has decreasing capacity.

 

[dave]

absolutely. there is MUCH variability in their calculations, which as I've mentioned before is an *ALGORITHMIC BEST GUESS* since actual lithium-ion battery capacity is impossible to accurately measure without fully draining the battery and fully charging it (which is BAD to do as that is a full cycle and really speeds up degradation). that's why I think this thread is a joke and a waste of everybody's time. what you think is decreasing rated range is NOT decreasing rated range. it's just variability in the factors used in their rated range GUESSING algorithm. this will fluctuate both up and down every day. could be down 5 miles one day, then up 8 miles the next. a total guesstimate based on dozens of factors that change daily.

Yobig, I appreciate your input on the matter, but do not appreciate you dismissing our opinions as a joke and waste of everybody's time.

My car has a display for rated range. That range has been decreasing since I bought the car. That means I have decreasing rated range. I'm not making it up, it is what it is, and I would like to understand why it is that way, and also why my loss appears to be greater than other folks. If there is an algorithm "guessing" my range, I'd like to know how it works and why it consistently displays mine as less then other peoples.

Your experience is obviously different than mine, as my maximum range does not variate at all. It has steadily gone down since I got the car in January. Certainly not fluctuating up and down on a daily basis as you are saying happens.

I have now done several range charges from a low SOC - one at 240/5A, and I have been charging solely on 240/5A for the last two weeks based on your (and others) advice. My top range has not improved by one mile.

- - - Updated - - -

Comparing my last 2 range charges, my range did go up. Last time it stopped @ 416km, this time it read 418km when it finished.

2 km doesn't count. That's barely 1 mile.

 

[Gear]

Yobig, I appreciate your input on the matter, but do not appreciate you dismissing our opinions as a joke and waste of everybody's time.

My car has a display for rated range. That range has been decreasing since I bought the car. That means I have decreasing rated range. I'm not making it up, it is what it is, and I would like to understand why it is that way, and also why my loss appears to be greater than other folks. If there is an algorithm "guessing" my range, I'd like to know how it works and why it consistently displays mine as less then other peoples.

Your experience is obviously different than mine, as my maximum range does not variate at all. It has steadily gone down since I got the car in January. Certainly not fluctuating up and down on a daily basis as you are saying happens.

I have now done several range charges from a low SOC - one at 240/5A, and I have been charging solely on 240/5A for the last two weeks based on your (and others) advice. My top range has not improved by one mile.

- - - Updated - - -



2 km doesn't count. That's barely 1 mile.

No offense, but is it really fair to be upset with somebody dismissing your evidence, and to then dismiss somebody else's all in the same post?

 

[yobigd20]

If there is an algorithm "guessing" my range, I'd like to know how it works and why it consistently displays mine as less then other peoples.

see my post here:
http://www.teslamotorsclub.com/showthread.php/22101-Can-someone-PLEASE-explain-how-rated-range-is-calculated?p=454531&viewfull=1#post454531

but specifically, reading these two patents will give you more insight: http://www.faqs.org/patents/app/20100138178 & http://www.faqs.org/patents/app/20110156641

 

[Eggplant]

Nice! Thanks for the links!

 

[Gear]

see my post here:
http://www.teslamotorsclub.com/showthread.php/22101-Can-someone-PLEASE-explain-how-rated-range-is-calculated?p=454531&viewfull=1#post454531

but specifically, reading these two patents will give you more insight: http://www.faqs.org/patents/app/20100138178 & http://www.faqs.org/patents/app/20110156641

I'm not sure why your quote got attributed to me, but I'm not the one who asked the question.

 

[yobigd20]

I'm not sure why your quote got attributed to me, but I'm not the one who asked the question.

Hmmm probably a copy paste error in my part. My bad.

 

[lloyds]

I'm at 9k miles now and no degration so far. Keeping my fingers crossed at this point since it's a bit scary to hear about these issues so early on.

 

[fluxemag]

The service center said my battery is operating normally, and went on to say that rated range decreases based on your driving habits. I'm not sure if that's true. Projected range using average mode is very effective at telling me how many miles range I can expect. Rated range displayed on the charging screen is still way higher than what I could actually get at 350 Wh/mi. So why is the rated range so ineffective at catching up to my driving style if it actually does try to do that. You would think it could do it faster than 1 mile lower every two weeks.

So my question for other "40" drivers is, if what is your Wh/mi and rated range on a full charge?

 

[Sacrament055]

My 40 shows a rated range at full charge has gone down from 145 (new) to now showing 136 to 139 now (depending on the day). I've been very careful to drive efficiently and am now down to 270 wh/mile. Despite the 136 rated miles I can fairly easily drive 150 miles on a full charge. I suspect that will change when the winter weather hits.

 

[Kipernicus]

Just adding a datapoint.

10k miles, 60kWh, Jan 2013 delivery
90% charge today = 175 rated range

 

[nleggatt]

60 with 22k miles still getting 200 miles on full charge

 

[Red]

Always keep in mind the season or date of when you look at the estimate. Cold or heat eat more energy than those points in between due to heating and cooling... And the car remembers recent consumption pattern and makes assumptions based on that.

 

[nanimac]

So my question for other "40" drivers is, if what is your Wh/mi and rated range on a full charge?

I'm at 4,000 miles, 291 wh/mi and 135 full charge

 

[mdh]

Always keep in mind the season or date of when you look at the estimate. Cold or heat eat more energy than those points in between due to heating and cooling... And the car remembers recent consumption pattern and makes assumptions based on that.

Is this true when looking at "rated" range and not projected?