Battery range calculation decrease with 2023.44.30.5.1?

[surfrasch]

Five year old Model 3 purchased November of 2018, build number around 122,000. I know the initial battery degradation occurs in first two years, my range dropped quickly at about 25k miles from 310 miles to 285 to 290 roughly. I also know range is a calculation, I've spent lots of time learning the basics from this forum. I've been only charging to 50% for maybe three years now, and I only jack it up to 100% for a longer trip.....maybe once per month. My range stabilized to a fully charged 290 to 292 miles for the past two years, extremely consistent.

Before the holidays I upgraded to 44.30.5.1, and instantly the calculation changed. Full charge is now 284 miles max.

Okay, I know this is all funny money somehow, the battery hasn't changed overnight and all.....but this is the type of stuff Tesla does that drives people nuts. They advertise a number of improvements with a software update, but then other seemingly unrelated stuff changes, quite often not for the better.

Anyone else notice a range calculation decrease after this update?

 

[KenC]

Sorry, no. I have a Dec '18, and the same software update, but I just looked and I'm showing the full 310miles, based upon 177mi at 57%.

 

[UncleCreepy]

I bought my M3 LR AWD in December 2019. Drove 84 k miles since, max range as of today is 295 miles. No change with the latest update to 2023.44.30.5.1.
I usually charge to the recommended daily max recommended by Tesla which used to be 80%, later 90%, and now 80% again. It doesn't seem to matter, but I rarely ever supercharge.

 

[3sr+buyer]

My range stabilized to a fully charged 290 to 292 miles for the past two years, extremely consistent.

Before the holidays I upgraded to 44.30.5.1, and instantly the calculation changed. Full charge is now 284 miles max.

Since the fully charged miles on the top of the screen are just the EPA economy times the BMS' capacity estimate, it appears that your car's BMS has lowered the capacity estimate, whether or not that is related to the software version.

 

[surfrasch]

Since the fully charged miles on the top of the screen are just the EPA economy times the BMS' capacity estimate, it appears that your car's BMS has lowered the capacity estimate, whether or not that is related to the software version.

It had to be related to the software.....the BMS estimate changed instantly after the download. At the time I thought this is weird, maybe it will recalibrate with some time....but so far no, just staying low.

Anyhow, it's good (or maybe not good?) to see others with similar age car had no issues.

 

[AlanSubie4Life]

It had to be related to the software.....the BMS estimate changed instantly after the download. At the time I thought this is weird, maybe it will recalibrate with some time....but so far no, just staying low.

Anyhow, it's good (or maybe not good?) to see others with similar age car had no issues.

I think there are examples in past times of software updates causing this, but it probably does not happen to every car. I could imagine them closing "holes" in their BMS estimation firmware with every successive release. And I think this did happen much more in the early days.

It's also possible it was just a coincidence - BMS capacity estimates often seem to happen in large jumps of 6-8 miles or so. Might have just been the reboot which finally convinced the BMS it should update its estimate (I think it probably cogitates a good long while on this, comparing estimate updates after each sleep cycle over the long term, and when consistently seeing that the battery is at a lower SOC than the dead reckoning predicted (dead reckoning is used during driving, since it seems the BMS cannot look accurately at the SOC when the battery is not showing its OCV), then it will eventually decide your pack just doesn't have the capacity it thinks). And then it steps downwards.

You can probably actually track this carefully now with the energy screen (the adjustments up and down on each park/sleep cycle), but I haven't seen anybody actually do it. TeslaFi and any other of the tracking apps could do this relatively easily I think, but none of them seem to do so. I guess it is complicated by Sentry use, etc. But if you never used Sentry or any features, it might be possible to keep track. I'd expect that consistent downwards adjustments would eventually lead to a reduction in the capacity estimate. And subsequent to that adjustment, I'd expect the steps when parked to be smaller (dead reckoning works better in that case, because BMS estimate is better matched to the true capacity).

 

[David99]

Tesla is constantly updating the BMS and it's abilities to predict the amount of energy available to the car. It is far more sophisticated than just keeping track of energy in and out, balance and temperature.
I think it is important to keep in mind that battery capacity isn't like water in a tank. The amount of water in a tank is fixed and doesn't change with temperature or the method of how you add or take out water, neither how fast or slow you do that. Energy in a battery is not that simple. There are a lot of factors that affect how the energy goes in, is stored (or not) and how you can take it out. A battery doesn't collect matter that is then released again. It is the flow of Lithium ions which is a chemical process. How well that process works determines how much flow of electricity you get. The new software might just be better at figuring all of that out and come up with a different result than the older software.

 

[KenC]

Since you've been only charging to 50%, try sliding the level up and down and resetting it to 50%. A 6mile change in estimated range is only 3mile difference at 50% SOC, and the variability for 1% is 3miles.

 

[surfrasch]

yep thanks....actually charged to full a few days after the update to see if this affected anything. One other strange thing I'm noticing, sitting in my garage plugged in.....I'm getting some vampire drain that I never saw in the past. Sentry off, charger set to 50% Tuesday evening after driving around, it charged up to 141 miles, now I'm at 136 mile range Thursday morning. It never did this in the past, always held to the charge set point. I rebooted last week a few times with the 2 finger and brake option.....no change.

hmm....strange one, thanks all for the feedback, seems I'm an anomaly!

 

[3sr+buyer]

Regarding vampire drain, does the energy screen park tab indicate any place that is consuming energy while parked?

 

[surfrasch]

good point, just checked....I know it's down about 5 miles since Tuesday evening charge, the energy park tab says it's down 2.2 miles, all due to "vehicle standby". Hmm....what would that be?

 

[AlanSubie4Life]

good point, just checked....I know it's down about 5 miles since Tuesday evening charge, the energy park tab says it's down 2.2 miles, all due to "vehicle standby". Hmm....what would that be?

BMS adjustment after the dead reckoning of the vehicle charge event, partially.

I think potentially this is good. If it over-estimates after a charge potentially the pack has slightly more capacity than the BMS thinks...I think. See what happens after drives on this page. I think consistent steps up after driving, followed by short sleep events, indicate a pack with higher capacity than the BMS thinks. I think.

 

[outdoors]

My 2017 3 RWD was normal for the first couple years til just recently. Opposite of your situation I had a range increase. I do charge to 90% each and every day, and 100% when I need to some may want that information.

Strange as it the cold time of year when my usual range drops occurs. I did notice as it was right after the update in question.

 

[surfrasch]

BMS adjustment after the dead reckoning of the vehicle charge event, partially.

I think potentially this is good. If it over-estimates after a charge potentially the pack has slightly more capacity than the BMS thinks...I think. See what happens after drives on this page. I think consistent steps up after driving, followed by short sleep events, indicate a pack with higher capacity than the BMS thinks. I think.

Thanks....interesting....we shall see! When my range initially dropped three years ago, I read up on the forum about the BMS system calculations, and the need to give it more low and high range info.....also to keep state of charge lower. I did all that and over a 2 year period it stabilized really nicely around low 290's for 100% charge. The software update and change in range were instant, freaked me out.

My 2017 3 RWD was normal for the first couple years til just recently. Opposite of your situation I had a range increase. I do charge to 90% each and every day, and 100% when I need to some may want that information.

Go figure, ehh?.....hey, they transferred my range to you!!

 

[jaqueh]

Same thing happened to me. I was consistently at 321/353 but now am consistently at 308/353 after the update. Like a day later to have this effect

 

[Eric33432]

Did you see where Tesla reduced the EPA range on their website recently, in an apparent response to complaints that they were being too optimistic? I wonder if these changes people have been reporting are due to the software being changed to reflect the changes to the EPA range estimates.

If that is the case your car should still have the same range it had before this change, which was never the EPA range for real world driving.

 

[AlanSubie4Life]

I wonder if these changes people have been reporting are due to the software being changed to reflect the changes to the EPA range estimates.

No.

 

[David99]

Did you see where Tesla reduced the EPA range on their website recently, in an apparent response to complaints that they were being too optimistic? I wonder if these changes people have been reporting are due to the software being changed to reflect the changes to the EPA range estimates.

If that is the case your car should still have the same range it had before this change, which was never the EPA range for real world driving.

That's actually interesting. The Model Y went from 330 to 310 miles of range. The Performance from 303 to 285. And you are right, the car has the same range. Just the way they calculate the rated range has changed.

 

[AlanSubie4Life]

These changes will not apply to vehicles that have been sold and are in customer hands (exceptions for very recent purchases maybe, but not the topic here).

Going forward newly sold vehicles will have no change to capacity and will have no change to their potential range (exceptions for changes to programming that eliminate the option for various less efficient drive modes).

However, the display will be altered to show a lower number of more energetic rated miles (rated miles are a unit of energy).

 

[surfrasch]

Same thing happened to me. I was consistently at 321/353 but now am consistently at 308/353 after the update. Like a day later to have this effect

excellent, so I'm not going crazy.