Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health

[Mendione]

Thank you all for taking your valuable time and answer my questions. I really appreciate that. Thank you all for your advises. I guess I have to switch my mindset from gas car to EV car. Which is somehow not easy. I will, eventually I will.

I got 85% of charge from the aventura mall, and 3.0 miles later (my home) I parked my car with 83% and this morning, with all turn off, My beloved Tesla woke up in the cloudy summer florida morning with 81% (must be that my Tesla is dreaming a lot) .

I have not yet the charger installed at home, because TESLA does not have the GEN 2 NEMA 14-50 adapter (by the way, this is something that a responsible and serious company should not let it happens, to put their customers in a ordeal to find, in this case, an adapter). I do understand that the Tesla love to be plugged so its battery are fully charge (85%) all the time.

Anyway, again, I want to thank you all for using your valuable time answering my tesla wonderings, and for having that will to help others. Tysm.

 

[jjrandorin]

(moderator note)

I have decided I will no longer be merging new posts on the topic of battery degradation, etc into this thread. I will not lock this thread, but will let the posts on this topic stand alone in this subforum if they are posted in separate threads, and members can, or can not answer them.

This means that the model 3 battery and charging subforum will be more aligned with the other vehicle battery and charging subforums, with multiple separate threads on this topic, and this particular thread will fall or rise as people post in it, just like other threads.

 

[3sr+buyer]

Good morning! I am a new Tesla Model 3 RWD owner. I bought it used, its a 2021, and only has 12,000 miles. I drove it the first time to my town grocery store and back home, only maybe 20 miles total, but percent went from 80% down to 58%?! I have driven it to work all this week and switched from % display to miles, and the miles is always off in comparison to actual miles driven and miles lost per battery. For instance, i actually drove 75 miles round trip, but car battery shows a loss of 112 miles. Only driving 75 miles and battery % went down 47% (89% down to 42%). Oh, and the battery will lose 5% just sitting there from work arrival at 8 am to 4:45 pm. Is this normal or should i have dealership do something about this before its too late?

The mileage next to the battery icon is rated mileage. If you drive less efficiently than the rated mileage, you will see it go down faster than the actual miles driven. You can bring up the energy screen to see if your actual consumption (dotted line) is higher or lower than the rated consumption (solid line).

Consumption while parked can occur if sentry mode is on or cabin overheat protection is on.

 

[AlanSubie4Life]

You can bring up the energy screen to see if your actual consumption (dotted line) is higher or lower than the rated consumption (solid line).

Note that in order to get “parity” mile-for-mile rolloff, your trip meter efficiency must be:

Trip meter for parity = 0.99*0.955*(rated consumption line - 5Wh/mi).

For example, for a 2018 Model 3 the rated line is at 250Wh/mi.

Parity occurs at:
(250Wh/mi-5Wh/mi)*0.955*~0.99 = 232Wh/mi

All easily verified by any user themselves, of course, and this is a rough guide; due to BMS fluctuations, the relationship can bounce around a bit for a particular drive, but this is the approximate average.

And to be clear, the trip meter efficiency reported does match the position of the “recent efficiency” line on the Energy Screen. There is not a mismatch there.

 

[Jeremy3292]

Data point: I'm at 20k miles on my 2021 M3 LR and still charge to at least 353 miles at 100%. Zero apparent (visible) degradation.

 

[Steve446]

Data point: I'm at 20k miles on my 2021 M3 LR and still charge to at least 353 miles at 100%. Zero apparent (visible) degradation.

That's not unheard of. Some M3 LR owners do have apparently no or little obvious degradation after 12 or more months (read these pages for more details). Others are no so lucky and can have several percent loss (up to ~10%) after a year from calendar aging and maybe cyclic aging. It all depends on a number of parameters such as battery chemistry, average SoC, and temperatures (ambient and battery), charging habits and driving style. if you want to delve into the actual state of your battery then install SMT (as an example). That would provide you with more insight into the battery status of your car. That's interesting for some, others just want to enjoy their car

 

[AlanSubie4Life]

I'm at 20k miles on my 2021 M3 LR and still charge to at least 353 miles at 100%

I can’t remember when you got your 2021 and whether you ended up with the 82.1kWh or the 77.8kWh battery.

The 82.1kWh batteries got a software update sometime at the end of 2021 to bring them up to 358 miles (like the 2022), as I recall (no change to constant, just an increase of the degradation threshold - 2021 owners can correct me if I am wrong - though of course whether you saw this full increase depends on whether capacity was above 79kWh at the time of update).

Anyway seems like you’re doing fine either way. The 82.1kWh 2021 AWD vehicles will tend to not show capacity loss (even though it is happening) as soon as the 77.8kWh vehicles though. If you have a 77.8kWh battery you are doing very well. Of course what matters is the range, and it is better to start with a 82.1kWh battery for that (more margin for capacity loss).

 

[Jeremy3292]

I can’t remember when you got your 2021 and whether you ended up with the 82.1kWh or the 77.8kWh battery.

The 82.1kWh batteries got a software update sometime at the end of 2021 to bring them up to 358 miles (like the 2022), as I recall (no change to constant, just an increase of the degradation threshold - 2021 owners can correct me if I am wrong - though of course whether you saw this full increase depends on whether capacity was above 79kWh at the time of update).

Anyway seems like you’re doing fine either way. The 82.1kWh 2021 AWD vehicles will tend to not show capacity loss (even though it is happening) as soon as the 77.8kWh vehicles though. If you have a 77.8kWh battery you are doing very well. Of course what matters is the range, and it is better to start with a 82.1kWh battery for that (more margin for capacity loss).

8/2021 build date so 82 kWh pack for sure. Yes, I did get the software update that took it to 358 miles at 100% in December/January timeframe. That was short lived though but I guess you could say I've "lost" 5 miles from 358 to 353, but the car was delivered with the 353 rating.

 

[AlanSubie4Life]

8/2021 build date so 82 kWh pack for sure. Yes, I did get the software update that took it to 358 miles at 100% in December/January timeframe. That was short lived though but I guess you could say I've "lost" 5 miles from 358 to 353, but the car was delivered with the 353 rating.

Yes, in the end it is range that matters (which is correlated to the energy indicator).
But if discussing capacity loss precisely (to help people with expectations) it’s better (in my opinion) to think of your situation as being ~78kWh from your original 79-80kWh. (82.1kWh packs in 2021 LR AWD rarely gave over 80kWh, though the current situation for 2022 packs is unclear - the EPA test Tesla did got 82.1kWh (measured differently).)

In any case it’s good that you got the larger pack. You’re ahead of where you would be otherwise, as you say.

 

[Steve446]

8/2021 build date so 82 kWh pack for sure. Yes, I did get the software update that took it to 358 miles at 100% in December/January timeframe. That was short lived though but I guess you could say I've "lost" 5 miles from 358 to 353, but the car was delivered with the 353 rating.

I don't want to put a downer on this but 5 miles on 535 is slightly less than 1%. Based on what I read in these forums, and my own experience, assessing a "loss" of ~1% could be within the intrinsic error of the systems measuring that value Honestly, I would ignore that.

 

[Jeremy3292]

I don't want to put a downer on this but 5 miles on 535 is slightly less than 1%. Based on what I read in these forums, and my own experience, assessing a "loss" of ~1% could be within the intrinsic error of the systems measuring that value Honestly, I would ignore that.

I'm not worried about it all. When I picked up the car it said 353 miles at 100% and 20k miles later it still says 353 miles at 100%. Makes me feel like my OCD charging habits have been worth it or at the very least I got a good draw on the battery lottery. Either way it's good enough for me!

 

[Perscitus]

Wishful thinking as that is not how it works. The estimated range (either in terms of miles or in tems of SoC% is just a mediocre estimate of range and a poor indicator of degradation).

Newer build users need to rack up many more discharge/charge cycles and years of service out of their batteries (almost regardless of total mileage) to potentially see degradation reflected in their range estimate. And even then, there are way too many variables, including BMS behavior, to infer degradation based on 'est range when new' vs 'est range now'.

 

[blkswn]

Update 2: Another 10 days and 607 miles with battery drained down to 30% and another Supercharge and few L2 charges later, 100% estimated range is 300 miles. It's been about 1 month and 1,776 miles now since service reset the battery cycle count.

Update 3: 12 days and 749 miles since last update. Drove car down to 15% and charged up to 90% twice in this period, while letting the car sleep at various SOC as much as possible. 100% SOC estimate settling in at 292mi. How not charged to 100% yet.

 

[AlanSubie4Life]

Update 3: 12 days and 749 miles since last update. Drove car down to 15% and charged up to 90% twice in this period, while letting the car sleep at various SOC as much as possible. 100% SOC estimate settling in at 292mi. How not charged to 100% yet.

I'd expect your vehicle to continue dropping for a while, to something like 290 miles, but the 267 didn't seem very reasonable so hopefully that doesn't show up again at the end of this!

Hey, hopefully it stays at this level and it's really correct. This would certainly put you right around the typical result (the basis of my random guess).

 

[andy92782]

Current stats:

2018 LRAWD with 19s (10/18 build)
~27.5K on the odometer
260 Wh/mi lifetime (trip computer)
SoCal (not cold)
80% daily charging for much of its life w/ infrequent Supercharger visits (<1x/mo over the car's lifetime).

Current 100% estimated range is ~268. I'm changing my routine away from daily charging and trying the BMS calibration procedure outlined in this post to see if it helps recover any range although I'm not terribly optimistic it will.

I've used Teslamate to track data for the past ~2.5 years. Here's a chart showing predicted range vs. odometer since I started using it:

 

[AAKEE]

Current stats:

2018 LRAWD with 19s (10/18 build)
~27.5K on the odometer
260 Wh/mi lifetime (trip computer)
SoCal (not cold)
80% daily charging for much of its life w/ infrequent Supercharger visits (<1x/mo over the car's lifetime).

Current 100% estimated range is ~268. I'm changing my routine away from daily charging and trying the BMS calibration procedure outlined in this post to see if it helps recover any range although I'm not terribly optimistic it will.

I've used Teslamate to track data for the past ~2.5 years. Here's a chart showing predicted range vs. odometer since I started using it:

View attachment 828173

The real range the car can go will not change from a BMS calibration. It might give the BMS more points for the calibration and increase the on screen range though.

It possible to estimate the degradation from time and cycles if the average SOC and average cell temp is known.

Here is a calculation to what expect about the degradation, with guestimates about the avg SOC and avg cell temp:

Assuming average SOC is around 70% (7000 mi/year ish = short daily drives and charge to 80%)
The cycles can almost be ignored, I added 0.5% to each year to the calendar aging in the list below.

I assumed average cell temp in middle between the 25 and 40C curves. Do not know if the car stands in the sun, but the battery seem to get about 5C or more warmer than ambient when parked in the sun. Charging and driving also heats the battery so the average cell temp is well above the ambient temp.
Degradation( loss of battery capacity)
7.5 % after one year
11 % after two years
13.5 % after three years
16 % after four years

I think the original range is 310 miles and that the degradation threshold is 76 kWh.
We can loose 1.8kWh from the full pack when new capacity without loosing range.

If the capacity is transfered to range via 76000/310 = 245 wh/mi(the constant), the range should look like this:
New - 310 miles
After 1st year - 294
After 2nd year - 283
After 3rd year - 275
After 4th year - 267
After 5th year - 260
After six years - 254

I think it is a coincidence that my estimate and your current 100% range is so close.
The average cell temp was not chosen very exact but by guesstimating, same for the SOC. But we have some values to refer to for about what to expect. If the avg SOC and average cell temp is about correct guessed I think your BMS is about on track.

Anyway, the true degradation will follow a curve that looks about as the range list by year above. True capacity will only go one direction - down. This will happen slowly and step by step even if the BMS will show it in chunks or even increase the range.

I guess BMS calibrations sometimes raise the range but after returning to the regular schedule, the range drop back to about the previous value.

 

[KenC]

Current stats:

2018 LRAWD with 19s (10/18 build)
~27.5K on the odometer
260 Wh/mi lifetime (trip computer)
SoCal (not cold)
80% daily charging for much of its life w/ infrequent Supercharger visits (<1x/mo over the car's lifetime).

Current 100% estimated range is ~268. I'm changing my routine away from daily charging and trying the BMS calibration procedure outlined in this post to see if it helps recover any range although I'm not terribly optimistic it will.

I've used Teslamate to track data for the past ~2.5 years. Here's a chart showing predicted range vs. odometer since I started using it:

View attachment 828173

Interesting. My car was built almost the same time as yours. Oct 2018, LR-AWD. 36,600 miles. ~254Wh/mile. Maine, quite cold. 60% daily charge for last 3 yrs, with about 20% supercharger miles.

My current EPA estimated range is 310 miles. According to SMT, my battery is 77.0kWh still.

 

[andy92782]

You can see from the graph that the Projected Range really took a nosedive last summer. Is this coincident with the onset of warmer weather? Is the same thing happening this year? Notice the recent step down.

My car also shares a garage with an ICE. It's not vented to the outside and it gets HOT in there during the summer months.

When the eventual day comes I decide to move on from this car, I will probably change my charging habits away from an "80% every day" strategy.

 

[BBen]

10,000 miles. I have charged to 100% about 5 times.

Normally routine is to drain the battery to around 15% and charge to 90%. About one charge every 3-4 days. I do not follow the plug it in all the time rule.

I think I’m doing quite well.

View attachment 429819

I am not sure. Your profile says it's M3 LR. LR has about 358miles at 100% (EPA tested), but you have 321miles so you lost 10%.

 

[AAKEE]

I am not sure. Your profile says it's M3 LR. LR has about 358miles at 100% (EPA tested), but you have 321miles so you lost 10%.

It doesnt look like a facelift ( ’21 or later).
As I recall it ’18/’19 has 310 miles max range as new, and show this on the screen.
From my memory ’20 had an upgrade to 322 miles and also show this on the screen ”when new”.
Should be a 2020 model, starting on 322miles?