I just received my new M3P (< 200 miles on the odometer). I left the max charge at the default of 90%. When charged to 90%, the range reported is only 263 miles, which works out to 292 miles @ 100% charge. That is quite a bit lower than the 310 mile range it is supposed to get. Is this an indication there is a problem with the battery installed in my car? I was thinking maybe I need to calibrate the battery by, say, charging to 100% then running it down to 10% or something like that.
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AlanSubie4Life
Efficiency Obsessed Member
As mentioned, the constants have changed. I guess that makes them...not constants? No they are constant - but very occasionally they get updated to match EPA.
Also, the 3P+ (on the window sticker) is EPA rated for 299 miles, not 310.
For data, if you can, please report your projected 100% range with the 18” wheels configuration selected. I expect about 313-314. Note this difference vs. 292 does not change your range.
Do not charge your battery to 100% unless you are planning to drive a fair distance. No need.
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I switched the wheel config to 18" aero and the range at 90% was reported as 279 mi, which works out to exactly 310 mi at 100%, which is the advertised range. So that explains it (I was worried my battery was defective or something).
AlanSubie4Life
Efficiency Obsessed Member
A little lower than I expected based on other reports, but definitely the battery is fine. Use the 20” selection for better alignment with reality of course.
This 310 is equivalent to 248/245*310rmi = 314 rmi in the “old” system.
So these 2020 vehicles have the most energy available, ever, it appears. We will see.
It seems that Tesla finally tired answering questions about why the cars did not get the rated range. Should be a bit closer now. Though probably a bit short still.
Tesla only traded "why does my car not get rated range" with "why does my car not SHOW rated range when fully charged" in my opinion, because it appears they made these changes without any sort of "inform" to owners etc.
Tesla expects everyone to "just plug it in and drive" and many do, but, because of the nature of the car itself, many (many many) of the owners are "tech forward" and "data hounds" so will dig into this stuff. Couple that with the fact that almost every single new owner will see the number on the screen is a bit short and completely freak out ("theres something wrong with my battery!!!" My car used to show 279 at 90% and now it shows 268!!!! there HAS to be something wrong!!!!"), and it just makes people frustrated.
Telsa does a very poor job of communicating this type of stuff, which leads to extra stress on owners, especially new ones. Couple THAT with all the "forum wisdom" telling people "I charge to 72.8% because XXXXXXXX", "well, I charge to 85% because XXXXXX" and people get it in their head that they need to manage charging different than "just plugging it in", and focusing on it "because its a battery and I need it to last longer than my iphone".
Tesla should be over communicating on this and they dont... so people come to forums and post panic'ed messages about how there is something wrong with their battery because it shows 15 miles less than it "should" yet they charge to 77% every other day, and their commute is 22 miles round trip to work and back.
Even if the range of this car was 400 or even 500 miles, people would still be here posting "my car is rated for 500 miles, and it only shows 440 miles at 90%... whats wrong with my battery?!?!?"
AlanSubie4Life
Efficiency Obsessed Member
True. Though it is tough to do anything when people claim their car has 310 miles rated range when it says 299 right on the window sticker....
I wish they had just made the gauge read kWh or % or predicted range. Would be so much simpler to just have those options. (To clarify, it DOES effectively read in kWh but it is hopelessly obfuscated.)
Eventually people would figure out what a kWh is. And it is what shows up on their electric bill so we’d be slightly closer in that regard too. Though there would still be the standard confusion there...
BTW, @AlanSubie4Life I really want to thank you for continuing to help educate people (including me) here, giving them realistic data, and trying to help both new and veteran owners understand the energy usage for these cars. Been wanting to post a public "thank you" since you take the time to try to help almost everyone understand, and you certainly dont have to do that at all.
So, Thank you very much for your contributions!
Good stuff. Can you clarify whether the miles displayed (at whatever you percent you charged to) fluctuate based on the battery management system calculations. For example, if you have an SR+ advertised as 240 miles at 100%, should it always read something close to 240 with a healthy battery or does the BMS factor in your real average into the calculation and display how many miles it estimates you will get on a full charge? For example, if it sees I have been trying to beat my best 0-60mph times or driving 90mph or doing laps on a track does it factor this into how many miles the next “full charge” will provide?
I guess there are two approaches. One, you can always indicate what is advertised, say 240 miles, and then watch the miles drop faster than you actually drive them. Two, estimate how many miles a full charge will provide based on historical wh/m usage, which would better match real world.
I guess there are two approaches. One, you can always indicate what is advertised, say 240 miles, and then watch the miles drop faster than you actually drive them. Two, estimate how many miles a full charge will provide based on historical wh/m usage, which would better match real world.
AlanSubie4Life
Efficiency Obsessed Member
This has no effect unless it affects the BMS estimate of how much energy is in the battery.
The BMS estimates how much energy for a “full” pack there would be, and it also estimates how much energy remains before shutdown is enforced.
It takes this “remaining” number, subtracts the buffer kWh (the buffer size is about 4.5-4.7% of whatever the “fullkWh” size is), and divides by the charging constant, for the displayed miles. For the SoC % it is a similar, related calculation.
All that matters for the display is how much energy the BMS thinks you have left; it is not based on prior behaviors unless those have affected the battery or created error in the estimate for some reason.
In the case of this thread, the code is now dividing that BMS kWh value by a larger number, so the resulting displayed number is smaller even if the kWh value (which is what really matters!) is the same.
Separately, the Energy Consumption screen calculation results and the SoC % seem to be suggesting that some additional energy has been unlocked. (Also, the constant with 18” wheels is slightly larger than before and the maximum range being reported with this constant for brand new vehicles is 310 or greater, so that also implies more energy is available than there is in 2018/2019 vehicles.)
There’s some small uncertainty on the exact amount of extra energy, until we get more good data. And there is the question of whether Tesla will align the display to EPA results (not required but they probably will). That would necessitate another constant change (they would make it smaller by 2-3%). Whether that will come with an actual efficiency improvement is anyone’s guess (it does not have to if the current vehicle performs as in the EPA test).
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Thanks. I am trying to figure out why our SR+ range seems to be trending down lately. I have seen where in some cases the displayed miles trend up after a charge, but lately they have been trending down quite a bit. Are we supposed to trust what it says in the slider in the app? Last weeks it showed 224 miles at 100% this week it shows 213 miles. Any idea if a hard reset clears any of the counters in the calculations?
By the way, 7000 miles, never supercharged. Charge at home with wall connector at 32 amps.
On the other end of the spectrum, my M3P+ was showing 310 miles on a full charge and now 305 miles this week. I assume it will keep trending down to the 293 miles folks are seeing in this thread.
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AlanSubie4Life
Efficiency Obsessed Member
I have not seen it be any better than what I can calculate by hand. Definitely do not trust it at low SoC.
I would recommend taking a picture of your Energy consumption screen and posting in an appropriate SR thread and tagging me if you want.
The picture should show your battery gauge in miles (or km), your projected range, and your recent efficiency numbers. They should all have three digits so do it at a relatively high SoC. Also as a bonus swap to % and take a picture there as well.
This projected 100% value is a large change (unless it has recently gotten freezing cold and the prior number was warm), and makes me wonder which constant is being used - picture is the only way to know (I’m making some assumptions about them not changing certain ways calculations are done, but we have to make some assumptions).
With the original constant 213 miles would mean 213rmi*219Wh/rmi = 46.6kWh. Compare to a new pack at 52.6kWh. That is 11% loss of available energy.
But if the constant has changed (do you have the 20” wheel config selected?), that could just have changed the displayed value with no change in energy. You can also just change the wheel configuration and report what happens to your rated miles.
Most likely this is real (possibly temperature related) though. I don’t expect this sort of constant change to the 2019, or at least it has not yet been reported. But maybe they have the wheel config have an effect even for older vehicles. Does not do anything on my 2018 (yet...).
It does seem from the 223 number that you have a minimum of 7% loss of capacity. That is unlikely to be related to the constant.
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AlanSubie4Life
Efficiency Obsessed Member
I doubt it. That was a step change on 2019.40.50.1. It was instant as you would expect. And so far only reported on 2020 3P (?) vehicles.
305 miles is probably due to temperature. Or just normal loss of capacity (about 1.2kWh, nearly 2%, so far). I’m at 3% loss of capacity after 13k miles, on my 3P+ (2.5kWh) - and it has nothing to do with temperature.
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