Decreasing rated range.

[brianman]

You have to factor in that some people treat their battery like sh.., and some baby theirs. Different charging habits will also affect things. There are so many variables, it's no surprise that such a wide range of rated range posted here exist.

Let me fix this for you.

You have to factor in that some people treat their battery like an advanced technology meant to be utilized rather than coddled, and some baby theirs.

How quickly people moved from "drive it like you stole it, it's a real car!" to "drive it like a hypermiler Prius" when they got their batteries and went into nanny state mode.

Hell, even Elon told us to use the damn things without reading the manual. "Sir, yes sir!" I say.

 

[aaron.s]

You have to factor in that some people treat their battery like sh.., and some baby theirs. Different charging habits will also affect things. There are so many variables, it's no surprise that such a wide range of rated range posted here exist.

qwk

I know both MD owners personally and can say they both drive their cars in similar manners....

Aaron

 

[dave]

It's too complex a calculation to be concerned by swings of a few miles this way or that.

I don't have a swing. My lost miles have never come back, and I don't even have variance of more than a mile in my daily numbers - despite trying to shake it up with deeper charge cycles and lower amperage charging.

Do you know for certain they don't have a bug (or a design change) in firmware that grew the amount of reserve or changed the calculation based on telemetry data from the "fleet"?

No, but I'm on the same firmware as everyone else, wouldn't the calculation be the same for everyone?

You have to factor in that some people treat their battery like sh.., and some baby theirs.

That's the trouble - I baby mine. Other than occasionally flooring her on an onramp, I am quite conservative, only charge to 80%, and have only gone below 50 miles of charge once (last night) to see if made a difference in my mileage numbers.

I respect you guys a lot, as many of you have obviously spent much more time on this board and in Tesla research than I. However, it starts to feel sometimes like I'm trying to argue science with a deeply religious person. Whenever a conflict comes up, the answer is that it is a great mystery we can't understand, and we just have to have faith. Personally, I like to know how things work.

 

[yobigd20]

You have to factor in that some people treat their battery like sh.., and some baby theirs. Different charging habits will also affect things.

actually it's impossible for us to control the batteries. thats what Tesla's complex battery management system is for. The only thing we should be doing is having fun driving it. Driving it fast or slow makes absolutely no difference to battery life. There is only 2 things we can control. 1-> don't let your battery go to 0 and leave it sit there and 2) don't range charge it in hot climates and leave it sit there. Those are the only 2 outside influences we have on the battery pack. Also, battery management system + heating/cooling system "normalizes" the charging. So the rate we charge (5a/110v vs 300A/400V supercharge) also makes absolutely no difference to the battery life. The only effect that may have is on the individual cell balancing within each pack, but over time that will also be normalized, aka "re-balanced", by the battery pack management system.

So I drive it like it's meant to be driven. I don't baby my car. And I have 27k miles and a range charge of 265 about a month ago. No degradation at all and I enjoy it every day with no worries about how my "driving style" will affect the batteries. If you're constantly worried about it's battery I'd say relieve yourself of that stress and give the car to someone else that will actually enjoy it.

 

[Todd Burch]

I don't have a swing. My lost miles have never come back, and I don't even have variance of more than a mile in my daily numbers - despite trying to shake it up with deeper charge cycles and lower amperage charging.

Not a swing for a given car....I meant from one car to the next. There are so many different environments and operating conditions that different cars experience that it's not surprising the numbers vary by a few miles. Nobody's saying there hasn't been any degredation. We don't have the means to quantify it accurately, though. Using the range estimate probably doesn't give the whole picture.

 

[qwk]

Let me fix this for you.



How quickly people moved from "drive it like you stole it, it's a real car!" to "drive it like a hypermiler Prius" when they got their batteries and went into nanny state mode.

Hell, even Elon told us to use the damn things without reading the manual. "Sir, yes sir!" I say.

FYI, you can still drive the car like you stole it, and be nice to your battery. One example would be to keep the charge level above 50%, if you are going to lay into it at every stoplight.

 

[Doug_G]

Also, I'm a little concerned that hullaballoo on forums might lead them to start showing us "fuzzier numbers" because "clearly you can't handle" the raw numbers.

I really don't think that's going to change.

The Rated Range is an estimate! The car doesn't know exactly how much energy is available from the battery, because this is very hard to measure precisely. In fact Tesla seems to measure it more accurately than anyone. Regardless, it is only an estimate of how much energy is in there. And even if it were perfectly accurate, your range is going to be affected by real world conditions anyway - such as temperature, speed, wind, rain and snow, elevation, etc.

Regardless of all that, the gauge as it stands is incredibly useful. It does correlate fairly well with the vehicle's actual range. Also it really helps you monitor how well you're doing on a road trip. What I do is periodically mentally subtract the Rated Range from the GPS distance-to-go. If that number comes out larger than my margin (typically 30 km) I'm happy. If it starts trending down then I back off my speed slightly. If I have lots left then I might speed up, especially towards the end of the trip.

 

[ecarfan]

Speaking for myself, I'm not dismissing that there might be decreasing rated range nor that people have a right to be interested (and concerned, in some cases). But there's a lot of heuristics in those calculations. It's not like taking out a ruler and measuring that way.

Well said. Just because the dash display gives an exact number doesn't mean the number is precise.

 

[cinergi]

Update on my situation ... If you don't recall, I had a huge sudden drop to 219 a few months ago at 13.5k miles. See my prior post here.

Since then, it has slowly increased -- though my firmware has changed since then. I'm now at 222 for 90% (don't know about 100%).

Tesla has refused to provide me an answer thus far (I haven't exactly been pressing for it, either) but from what I understand, *they* were unable to agree on the answer and thus I haven't been provided one.

Here's what I think we need from Tesla:

• Public statement on what rated range is (clarify whether it's based on driving history)
• Update the energy graph's horizonal line and projected range estimation so that 290 lines up with rated range, not 310
• Explain the sudden changes in rated range
• Answer whether 219 rated after 13k miles and/or 9 months is normal

 

[bluetinc]

So I drive it like it's meant to be driven. I don't baby my car. And I have 27k miles and a range charge of 265 about a month ago. No degradation at all and I enjoy it every day with no worries about how my "driving style" will affect the batteries. If you're constantly worried about it's battery I'd say relieve yourself of that stress and give the car to someone else that will actually enjoy it.

Yobigd20,

It's great that your car is still charging up to 265 after 27k miles. The reason a number of us are so interested in this is that our mileage is below yours, yet we charge to ~250. If we were simply speaking of a couple of miles, I would totally agree with the no-worries approach. Perhaps there are a couple of bad battery packs out there, or perhaps we are simply in the normal degradation variance, but with a difference of almost 6%, it is enough to want to understand it better.

I've mentioned much of this before, but as a recap: My car charged to 275 miles when new. It now charges to ~250 miles. I have verified that this drop is not effected by the various software versions that my car has been on (I am only up to 4.5 currently so I can't speak to 5.0/5.6). The amount of "reserve" below 0 has not changed since the car was new. I have shown that this change is real, the amount of energy that I can use to drive from full charge to ~0 miles has in fact reduced by ~7.5kWh or ~9%.

I also want to be clear that we should expect degradation, it is a natural and unpreventable effect of age and use of batteries. Because battery capacity can not be easily measured and is in constant flux (at times going both up and down), Tesla has taken to hiding this as much as possible from all involved. They have decided that the best value, which was accessible in the Roadster (CAC) either through the software, or from Service, is not available to either (I have asked). This is, I believe, an unfortunate effect of the need to provide simple answers to very complex questions, when moving a technical product to the mass market.

Peter

 

[Odenator]

Or we could be seeing reduced range because the internal mechanism that limits the rate of charge at higher SOC and ends the charging process is mistakenly stopping the charge process too soon thinking it is at 100% at least that's what a SC tech told me after he spoke to the HQ engineers regarding my drop in rated mileage.

 

[bluetinc]

Or we could be seeing reduced range because the internal mechanism that limits the rate of charge at higher SOC and ends the charging process is mistakenly stopping the charge process too soon thinking it is at 100% at least that's what a SC tech told me after he spoke to the HQ engineers regarding my drop in rated mileage.

Is this explanation attached to a specific software version? If this were happening, I would expect that to be shown by the pack voltage at 100% to be low. Up to version 4.5, I have not seen the max pack voltage to vary.

Peter

 

[bigsmooth125]

If you're constantly worried about it's battery I'd say relieve yourself of that stress and give the car to someone else that will actually enjoy it.

I never understood the point of dismissive arguments like this that are made whenever someone has a concern/complaint about the car. It reminds of the people who belch, "Well if you don't like the US of A, just move to another country!"

No one in this thread has said that he doesn't enjoy the car. People are simply and reasonably concerned that their down-trending rated miles might reflect higher than expected degradation of their batteries. No one knows for sure; that's why people are submitting their data (fwiw) and discussing the issue. I suspect that for most people, a drop of 5-15 rated miles by itself is not a big deal. The concern is that this drop might be the start of larger trend going forward.

- - - Updated - - -

FYI, I've been charging at low amperage the last few weeks, and last night I deliberately took her down to 17 miles to see if it would make a difference. It didn't. I'm still hitting 224 at 90% and 254 on a full charge. VIN 3236, 10,000 miles.
Based on various reports, I'm starting to think the degradation has more to due with age than mileage. It seems like the lower range numbers are coming from those of us that have had our cars longer and through last winter.

I'm getting identical numbers as you. Only difference is I got my car in March and am at 12K miles now.

- - - Updated - - -

I don't have a swing. My lost miles have never come back, and I don't even have variance of more than a mile in my daily numbers - despite trying to shake it up with deeper charge cycles and lower amperage charging.



No, but I'm on the same firmware as everyone else, wouldn't the calculation be the same for everyone?



That's the trouble - I baby mine. Other than occasionally flooring her on an onramp, I am quite conservative, only charge to 80%, and have only gone below 50 miles of charge once (last night) to see if made a difference in my mileage numbers.

I respect you guys a lot, as many of you have obviously spent much more time on this board and in Tesla research than I. However, it starts to feel sometimes like I'm trying to argue science with a deeply religious person. Whenever a conflict comes up, the answer is that it is a great mystery we can't understand, and we just have to have faith. Personally, I like to know how things work.

You must be my twin. I treat my battery the same and have the same thoughts.

 

[ChriZ]

For what it's worth, I have a 60kwh and I've seen my 90% charge go from 181 to 177 now. Forgot what it was when I got it but I swear it was in the 190s. I have about 6k miles on the car running 4.5.

 

[Electroman]

I have seen folks go through a similar gyrations in Nissan Leaf forums about 20 months ago. When an owner brought up the possibility of heavy degradation many were dismissive and gave several possible explanations on the same lines I see here. But in a few months when the warm weather returned it was apparent that batteries were indeed degrading at a faster rate.

 

[gaswalla]

I have seen folks go through a similar gyrations in Nissan Leaf forums about 20 months ago. When an owner brought up the possibility of heavy degradation many were dismissive and gave several possible explanations on the same lines I see here. But in a few months when the warm weather returned it was apparent that batteries were indeed degrading at a faster rate.

I was thinking the exact same thing. The software changes are being way overplayed, and now Tesla is even mentioning range in the software release notes. Next summer will be interesting to see how our ranges are holding up.

 

[Kraken]

FYI, I've been charging at low amperage the last few weeks, and last night I deliberately took her down to 17 miles to see if it would make a difference. It didn't. I'm still hitting 224 at 90% and 254 on a full charge. VIN 3236, 10,000 miles.
Based on various reports, I'm starting to think the degradation has more to due with age than mileage. It seems like the lower range numbers are coming from those of us that have had our cars longer and through last winter.

I do think there is some degradation and I'm not dismissive of it like some people here. I'm not as worried about it as others, because I know that I never get that number anyway. I tell most people that I expect 200 miles range max out of my 85 when they ask. Anytime I'm driving that far, I'm definitely driving faster than 55 mph, I'm playing the radio, and using the air. Tis estimate hasn't changed even though the number has slowly and steadily decreased under similar conditions. I don't drive it crazy, but I do use the accelerator occasionally and I don't drive slow just to drive slow.

i think some of this range will eventually come back when the battery rebalances itself. I noticed about a mile or two increase (not nearly as much as I've lost) by going down to under 20 miles and charging with about 25% less amperage. It was the only time I've ever seen the range go up.

 

[jerry33]

I have seen folks go through a similar gyrations in Nissan Leaf forums about 20 months ago. When an owner brought up the possibility of heavy degradation many were dismissive and gave several possible explanations on the same lines I see here. But in a few months when the warm weather returned it was apparent that batteries were indeed degrading at a faster rate.

The difference is that there is solid data that the Roadster's battery degradation isn't affected by ambient temperature. Now I suppose it's possible that Tesla got it wrong in the Model S, but I really doubt it.

 

[brianman]

there is solid data that the Roadster's battery degradation isn't affected by ambient temperature.

Is this within a specific range (say -20F to 120F) or generally (like 0K to infinity)?

 

[qwk]

The difference is that there is solid data that the Roadster's battery degradation isn't affected by ambient temperature. Now I suppose it's possible that Tesla got it wrong in the Model S, but I really doubt it.

That, and Tesla actually cares about their customers. I'm sure that if someone experiences real degredation this soon, the pack will be swapped out for a new one because that is a likely indication that one of the modules has failed. They did this for roadsters quite a bit.

On the other hand, if someone loses 10 rated miles over the course of a year, I doubt that Tesla is going to do anything about it because the car is still way over 200 miles of range. That is the equivalent of a leaf losing about 3 miles of range, which could be done by sneezing wrong near the car.