[FRC]

I am not sure, but I thought that number doesn't depends on driving/charging habits, but only on EPA estimate and battery degradation.

Your driving and charging habits (mostly charging) can tend to confuse the BMS and cause an inaccurate display of range.

 

[galimpic]

Your driving and charging habits (mostly charging) can tend to confuse the BMS and cause an inaccurate display of range.

I am only talking about the number in miles when charged to 100%. Are we thinking about the same thing, the "Energy Display" that is always on the top of the screen and shows either the percentage or miles, not the rated estimate in the energy screen? I thought that top one doesn't use other parameters, and that at full charge it simply displays the EPA rated range when switched to miles, minus any degradation detected, and is hence a good tool to see how degraded the battery is. I changed my driving style wildly as I went from short city drives to long freeway ones, and it wasn't showing any difference (again, at 100%). Is there a topic or a site that discusses it in more detail?

 

[FRC]

I am only talking about the number in miles when charged to 100%. Are we thinking about the same thing, the "Energy Display" that is always on the top of the screen and shows either the percentage or miles, not the rated estimate in the energy screen? I thought that top one doesn't use other parameters, and that at full charge it simply displays the EPA rated range when switched to miles, minus any degradation detected, and is hence a good tool to see how degraded the battery is. I changed my driving style wildly as I went from short city drives to long freeway ones, and it wasn't showing any difference (again, at 100%). Is there a topic or a site that discusses it in more detail?

It is my experience and understanding that the displayed range number that you describe, can be and is affected by variances in the BMS. For example, if you consistently charge only in the 50-90% range that range number at the top of your main screen can become unbalanced and lead you to believe that you have experienced degradation when the truth is that your BMS needs to be rebalanced. If I am misunderstanding this, would a more knowledgeable forum member please clarify this!

 

[galimpic]

It is my experience and understanding that the displayed range number that you describe, can be and is affected by variances in the BMS. For example, if you consistently charge only in the 50-90% range that range number at the top of your main screen can become unbalanced and lead you to believe that you have experienced degradation when the truth is that your BMS needs to be rebalanced. If I am misunderstanding this, would a more knowledgeable forum member please clarify this!

I've found this article that suggests that a charge to 100%, with leaving it for a while will result in balanced cells, with some additional procedures if showing excessive degradation. Not that I think that OP's 267 miles is anything to worry about, but he may try it and see if it will go up.

 

[garsh]

I am not sure, but I thought that number doesn't depends on driving/charging habits, but only on EPA estimate and battery degradation.

That number doesn't take into account driving habits - it is determined by the BMS using EPA estimate and its current understanding of the state of the battery.

But your charging habits determine how good of an estimate the BMS is capable of making, and that will easily result in a 3 mile difference.

After driving to Florida and back, I let my car sit overnight at low SOC (~25 miles).
I checked this morning, and the Tesla app says I will have 267 miles at 100% charge. That's the lowest I've ever seen.

I'm going to charge it up to 90%, let it sit overnight again, and see if that helps calibrate the BMS.

Update: after sitting overnight at 90% SOC, it now shows 293 miles at 100% charge.

 

[garsh]

I've found this article that suggests that a charge to 100%, with leaving it for a while will result in balanced cells

We've had a member determine that Tesla will balance the NMC batteries at much lower SOC. It's not necessary to charge them to 100%.

We know from Tesla's own documentation that the battery triggers balancing once over a certain voltage around 90%. Charging to 92% should be enough.
The actual balancing or recalibration won't necessarily occur there. Once it is charged above 90 and can sit long enough to sleep, then it may take a long drive or a reduction below 50% before it actually recalibrates its capacity.

Last week I positively triggered a rebalance and boost in range as verified both in CAN data and on Teslafi, after charging to 92%, an hour later I had a long drive. Then while the car was parked at 46% and only Sentry mode running, starting after 15 minutes the range started going UP as logged by Teslafi while it sat for a few hours. I later confirmed the CAN showed a higher total capacity afterwards (only about 0.5kWh in this case). I just happened to be very closely looking at various numbers and documenting things throughout that day as I'm preparing a deep dive video into the battery.

Battery balancing is not a top-off, it is a burn-off. Recalibration does not occur while it is sitting there and charging, it occurs on a long discharge/drive. Charging to 100% does not help achieve either of these things...all it does is charge the cells to a defined maximum voltage in the software for the extremely rare case that you need that extra ten miles.

Battery balancing connects cells/bricks to small resistors to slowly bleed off the voltage of those that are higher than the others. This can occur at ANY time and is completely within the BMS and the battery pack. Tesla's early documentation stated it would occur when average voltage was over 4.0V, but is likely now occuring at any voltage. But to be safe, we say charge and sit at 90%, which is above 4.0V. Any higher is not necessary. It will probably still balance at 80 or 85% too.
But the reality is, unless you DC fast charge often, your battery is probably not unbalanced. It's just one thing to try if you are unsure.

Completely separate is recalibrating pack capacity. THIS is your estimated range. Its estimated capacity of each of the 96 bricks. This is entirely software algorithms attempting to guess what the chemistry of each brick can store. And the only way to do it is to count energy used between two voltages. Simply take the starting voltage of the pack while it's sitting and not connected...when it's asleep and charged 80-90%... then count current * volts * time = kwh or Ah or coulombs for a sizable discharge, say more than half the battery, on a long highway drive. Check the voltage when sitting again. The difference of two sleeping pack voltages give you reliable percentage-of-max. Over that percentage, how much energy was used? Now you have a new estimate for energy capacity. This is performed individually for each individual brick of cells. The sum is your total energy capacity, the estimated KWh of the pack. State of charge is then the percentage of energy estimated to be available. Estimated.

Now my range is fairly low as I mentioned, 299 mi and 11th percentile. So I assumed maybe my battery was somewhat unbalanced. So I charged up to 90% and ran a canbus log overnight, even waking up the car every few hours to force everything to transmit. And what did I see? My imbalance was only 6mV. That's incredible low. And no reason to trigger a battery balance. And sure enough several indicators showed the car did not bother to balance. A perfect example that charging to 90% or even 100% is not going to improve things, if the battery balance is not the problem.

The problem is I need a nice long drive, with a good rest/car sleep before and after. Which is why I stress this part of the advice. And for all we know, Tesla does not completely replace the battery calibration with one long drive. Maybe the calibration is the average of the last ten long drives! And that's something that a LOT of us haven't been doing since March, and why a lot of us have seen poor ESTIMATED range. Our batteries are fine, it's just the algorithms are not getting satisfying updates.

As always...don't speculate. Don't assume. Look at the data. We can see our min and max cell voltages. We can see the software estimated full pack capacity at any time. AND we can see how drastically pack temperature bends all this data as well. This is why I love to see live nerdy data in front of me, so I don't have to wonder what's going on, I can understand it instead.

 

[garsh]

I've found this article

BTW, that site looks like it contains machine-learning autogenerated articles. There are no author attributions on any of the articles, and it shows a ton of ads. I'd be careful about trusting any information found there.

whois information

 

[galimpic]

BTW, that site looks like it contains machine-learning autogenerated articles. There are no author attributions on any of the articles, and it shows a ton of ads. I'd be careful about trusting any information found there.

whois information

Thanks for all of your comments, it's important that every topic ends up with correct info.

 

[chuckles1357]

My Tesla 3 SR is only 4 months old with 4000 miles. It’s range has dropped from 273 miles to 267 miles at 100% charge, that is 2% in 4 months time. Is this normal? Anyone experienced same issue?

I have exactly the same; 4000 miles, dropped 273 to 267 in four months, a 2% drop. Losing one mile a month of range. The only consolation is if it continues to degrade at this rate, we will qualify for a battery replacement after 8 years. I'm thinking once it drops below the 70% guarantee i'm going to look into if i can get a new battery... i mean, it never hurts to ask.

 

[chicagobob123]

I have exactly the same; 4000 miles, dropped 273 to 267 in four months, a 2% drop. Losing one mile a month of range. The only consolation is if it continues to degrade at this rate, we will qualify for a battery replacement after 8 years. I'm thinking once it drops below the 70% guarantee i'm going to look into if i can get a new battery... i mean, it never hurts to ask.

I am thinking you have a LFP pack which drops some range then doesn't

 

[chuckles1357]

My car is less than a week away from arriving, so I'm trying to gather best practice intel. The 80% rule is ok with me. The once a week at 100% is ok too. Just trying to pick the best plan as I plan several trips over the summer. In short I'm glad I joined and heard all this before I plugged it in every day to max charge. My current plan is 100% about every two weeks and a max of 80% the rest of the time.

Chicagobob123, I'm doing the same with my 2023 Model 3 LFP. Keep us posted on degradation with your charging plan... I am really interested on hearing how it goes! So far for me i'm losing one mile of range a month over five months when my car was new, as i've said before. Thanks for posting!

 

[chicagobob123]

Chicagobob123, I'm doing the same with my 2023 Model 3 LFP. Keep us posted on degradation with your charging plan... I am really interested on hearing how it goes! So far for me i'm losing one mile of range a month over five months when my car was new, as i've said before. Thanks for posting!

Do what I can. I have over 2000 miles on the car already. Everything is going well with no mileage loss when charged to 100%. Still reports 273

 

[bf.cunningham]

My Tesla 3 SR is only 4 months old with 4000 miles. It’s range has dropped from 273 miles to 267 miles at 100% charge, that is 2% in 4 months time. Is this normal? Anyone experienced same issue?

My Tesla is now 8 months old and the Range has dropped 9.4% .

 

[chuckles1357]

bf, how many miles on your Tesla?

 

[chicagobob123]

My Tesla is now 8 months old and the Range has dropped 9.4% .

I now have 3700 miles had have lost 2 miles. At 100% I have 271 miles. So do you think its time based loss? The difference is stark.

 

[kpanda17]

I did a compelling post of LithIon vs LFP usable range, where I own both. MYP/LithIon 90% usable of 303 is 272 miles vs M3RWD/LFP 95% of 272 is 258 miles. Only getting max 90% of Lithion is a limiting factor vs 95% of LFP. This assumes bottom and top 5% of Lithion is unusable vs bottom 5% of LFP.
Wow, you get a lot from LFP for the money. Will be interesting to see what's next with the two battery choices. How does Lithion get to 500/600 miles as LFP/M3P is getting closer to 300/400 miles.

 

[chicagobob123]

I am waiting for the Gotion LMFP batteries which are supposed to be more energy dense and still cheap. That could increase the range or decrease the weight. Either way still great news.
I think it will be 2 years before another major break in the battery chemistry for cars 2025. What do you guys think?

 

[sudhirraom]

LFP is 100% no matter what.

Only once a week. Not daily. Tesla updated its recomondation in the screen . They used to say "charge 100% at least once a week" not changed to "Charge 100% once per week". The word atleast has been removed.

 

[p7wang]

 

[chicagobob123]

In my world I started with 272 and am now down to 262 after 35,000 miles. Its about 3.5% loss. If it continue to lose at this rate by 100K I should be down
about 249 miles. That's not too bad. Fingers cross this is a linear loss.