In all fairness, I may have misreported their exact words. They may have said "as expected".
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Told sudden permanent 15 mile loss of range is "normal"
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In all fairness, I may have misreported their exact words. They may have said "as expected".
mknox
Well-Known Member
Thought I'd post here, because it seems the most relevant thread...
I had never done a Range Charge but also noticed my Rated Range seemed to be dropping. For example, I am seeing 171 miles of range at a 70% charge, 230 miles at 90% and so forth. If I assume the slider percentages and Rated Miles are linear, this would mean that a 100% charge would come in at 244 to 255 (instead of 265).
Well, the other day I did a Range Charge and got some peculiar results. The car has always been very accurate at predicting how long the charge is going to take to complete. When I did the Range Charge, it got to the point where it was saying "5 minutes remaining" and hung there for 15 minutes or so. Then it dropped to 4 and took about 20 minutes to get to "3 minutes remaining". At this point I had 260 miles of Range and I had to unplug and leave. I'm not sure if it would have gotten above 260 miles (was at 260 from about the 5 minute remaining mark), but maybe it would have.
So for me, I've "lost" no more than 5 miles. My car currently has about 9,500 miles on it.
I had never done a Range Charge but also noticed my Rated Range seemed to be dropping. For example, I am seeing 171 miles of range at a 70% charge, 230 miles at 90% and so forth. If I assume the slider percentages and Rated Miles are linear, this would mean that a 100% charge would come in at 244 to 255 (instead of 265).
Well, the other day I did a Range Charge and got some peculiar results. The car has always been very accurate at predicting how long the charge is going to take to complete. When I did the Range Charge, it got to the point where it was saying "5 minutes remaining" and hung there for 15 minutes or so. Then it dropped to 4 and took about 20 minutes to get to "3 minutes remaining". At this point I had 260 miles of Range and I had to unplug and leave. I'm not sure if it would have gotten above 260 miles (was at 260 from about the 5 minute remaining mark), but maybe it would have.
So for me, I've "lost" no more than 5 miles. My car currently has about 9,500 miles on it.
From my data, it seems like they broke this in 4.4: Firmware 4.4 - Page 25
My experience is that the last couple percent take forever no matter what charger you're connected to. The rule of thumb that I use is that standard->100% takes 60-90 minutes.
mknox
Well-Known Member
I'm concluding that the correlation between slider percentage and Rated Miles is not linear. I get about 230 miles at 90% which would translate to 256 at 100%, but I actually got to 260 on a Range Charge and had to disconnect and leave before the Range Charge even finished.
mknox
Well-Known Member
I used to get 241 or 242, but that was before they introduced the "slider". I now get about 230 miles at 90% (but still get very close to Rated on a Range Charge). I think they either changed the algorithm or else the old "Standard Charge" was actually something higher than 90%. I have just over 10,000 miles on my car.
I was getting anxious about my battery too (being a previous LEAF owner and watching that battery degrade 30% after 25k miles, I still have some PTSD).. I extrapolated the percentages and range to 100% and my calculations kept getting worse and worse.. A 50% charge was giving me 105miles.. I did a range charge (and also experienced the extra half hour at the end of the charge while the battery presumably balanced),and I had 296 ideal miles - around 258 rated. I like using ideal miles for an assessment of battery capacity b/c it seems to eliminate other variables. This is on a car with 17k miles. Now my range at a given percentage is up again, but it keeps slipping every day. I think it is purely a software issue. As long one can get rid of the degradation anxiety, it really is not an issue.
There is reason for the "imperfect memories" and the "softness of assertions" on this front. Elaborating...
According to my logs, the following fields were introduced between by 1.31.11 (4.4) and 1.33.44 (4.5)...
- charge_limit_soc
- charge_limit_soc_std
- charge_limit_soc_min
- charge_limit_soc_max
Prior to that, the limit was only indicated via the "charge_to_max_range" boolean.
Thus in 4.4 and older firmware, "battery_level" was our best guess at the limit.
For my vehicle, I have one "aberration" charge of 96% (that I contacted Tesla about) and a handful of 94%. Apart from that half-dozen or so instances, the limit of 93% appears to have been applied.
Edit:
For completeness sake, here's some data:
- 1.31.11 -- 2103/05/19 -- battery_level 96 / battery_range 246.89 / ideal_battery_range 282.64 [2.57br/bl]
- 1.31.11 -- 2013/05/18 -- battery_level 94 / battery_range 243.28 / ideal_battery_range 282.64 [2.59br/bl]
- 1.33.61 -- 2013/08/12 -- battery_level 90 / battery_range 228.85 / ideal_battery_range 263.40 [2.54br/bl]
- 1.33.61 -- 2013/08/13 -- battery_level 88 / battery_range 220.98 / ideal_battery_range 254.34 [2.51br/bl]
Note that the matching ideal_battery_range in the first two entries above is not a typo. Curious.
The number in brackets is batter_range/battery_level so (integer rounding error aside) gives a feel for how many rated miles per SOC %.
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mknox
Well-Known Member
Yep. I was getting a little concerned until I did that Range Charge and realized I was still good.
You are seeing the effects of multiple things. First, the % numbers you mention are SOC, not range. These do not appear linear because of the "reserve" energy that is reserved for driving below 0 miles. Add to this that the standard charge has changed from 93% -> 90%. At a full charge of 260 rated miles (79,690Wh/306.5Wh/mi), you should have ~79,690 Wh of drivable energy (100%)(260miles*306.5Wh/mi). At 90% you would have ~71,721Wh. This would be displayed as ~232 rated range miles (71,227 Wh/306.5) and 494Wh not displayed as reserve below 0 at this point. This effect would be more pronounced at lower SOC, such as a 50% charge where there would be a display of ~121 miles with reserve of ~2470 Wh.
Peter
Peter
FredTMC
Model S VIN #4925
Yes. Its balancing the pack (imo). I posted about this before. The "ring of light" at the charge port will be SOLID green but the car says its still charging (and the app). I believe it's balancing pack during this time.
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Yes. Its balancing the pack (imo). I posted about this before. The "ring of light" at the charge port will be SOLID green but the car says its still charging (and the app). I believe it's balancing pack during this time.
We have in-car pictures suggesting that the car UI puts rated at 312 Wh/mi. Where is 306.5 coming from? Thanks.
It's from calculations that I've been doing in my car. I've discounted using visual graphics to determine this number. From what I've been able to gather, this number can be different for different cars, and I have definitely validated that two newer cars have a 302Wh/mi energy unit, while my car is different. As a side note, it appeared that the "ideal mile" energy unit was identical in all cars. If you have one number you can easily calculate the other with your numbers as ideal miles * ideal energy unit = rated miles * rated energy unit i.e. 254.34 * 266.5 = 220.98 * 306.7.
Peter
Peter
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