HV Battery Died with 7 miles range left showing on Range display

[gaspi101]

This is really bad. It usually indicates a failing battery of some form.

What vehicle type? Do you have some pictures?

Definitely very abnormal. It sounds like your BMS has no idea what is going on and Tesla will need to fix it. You have to make them go into the logs and figure out what happened at 6%.

Definitely completely unforgivable and not something that should happen. 6% is HUGE amounts of margin. It's not even close to an empty pack (it's about 10% left!). To put it in perspective, that's the amount of energy my Spark EV battery has in it when it is at around 40%, and can travel another 20-25 miles. (Yes, obviously it's a higher SOC & voltage for the Spark cells at that same energy content, which does matter.)

This is a serious issue. Definitely FORCE Tesla to look at it, go through the logs, and if necessary, replace your battery under warranty, if it is still under the mileage limit. This should NEVER happen. There's no excuse whatsoever for a failure like this. It's a warranty issue, for sure.

Unfortunately if you don't have documentation you may need to document another premature shutdown under controlled conditions. If nothing else this needs to be extensively documented within the valid warranty period just in case it fails out of warranty, so it can be covered under warranty outside of warranty.


Absolutely unforgivable. I note you have a P3D with 265 miles at 100%. This is absolutely massive capacity loss (20%!!!) and represents a pack that is really struggling and way outside the norm of capacity loss (my 2018 P3D is at ~292 miles). You do live in a warm climate and probably have kept the pack above 55% a lot.

This may be a contributing factor and your pack is probably on the verge of failure. It's a major safety issue. It's routine to rely on a pack to operate down to ~0%.

Thanks, I appreciate the support. The 3 is stable at 270ish miles at 100% (just updated numbers in signature), which according to Tesla is normal degradation. I haven’t run the 3 below 10% since 2020 or so, when I did the last long roadtrip in that car. But this happened on the 2017 X100D, which until recently was our reliable roadtrip car. Theoretically, the BMS should be more accurate on this older X than the 3 because it doesn’t need to sleep that long to adjust….theoretically. I had Tesla look at it and they insisted everything was fine and literally said that I should never let it get below 10%.

I took it to Tesla after the 3% shutdown (where I was planning on arriving at supercharger at 8%, but the estimate went down from 10% to 3% in a matter of minutes, see invoice attached…shut down happened less than a mile from the supercharger…had to push it to a gas station that was closed and plugged into the wall for 2 hours and then was able to limp it the last mile to the charger). Paid Tesla the $295 for the diagnostic just for them to tell me to not run it down to 3% and use the nav system (I was using the Nav system!!!). Called them after the 6% (spoke directly with service center tech), and they said the same thing. I don’t have any indication that they’re going to give me any different response so I’ll save myself the $295

 

[ewoodrick]

Thanks, I appreciate the support. The 3 is stable at 265 miles reflecting which according to Tesla is normal degradation. But this happened on the 2017 X100D, which until recently was our reliable roadtrip car. Theoretically, the BMS should be more accurate on this older X because it doesn’t need to sleep that long to adjust….theoretically. I had Tesla look at it and they insisted everything was fine and literally said that I should never let it get below 10%.

I took it to Tesla after the 3% shutdown, paid $295 for them to tell me to not run it down to 3%. Called them after the 6% (spoke directly with service center tech), and they said the same thing. I don’t have any indication that they’re going to give me any different response so I’ll save myself the $295

What was the outside temperature at 12:48 AM.

 

[gaspi101]

What was the outside temperature at 12:48 AM.

Florida in August, so about 75F, and the road is always flat flat flat. Makes (or used to make) roadtrips very easy to plan. The energy graph was always perfectly reliable, and I would ensure to modulate driving speed to ensure to arrive at the SC with 5-10%. Recent roadtrips have been done the same, but now I target 15-20% and cross my fingers that I don't get a shut down at those SOC.

 

[ewoodrick]

Florida in August, so about 75F, and the road is always flat flat flat. Makes (or used to make) roadtrips very easy to plan. The energy graph was always perfectly reliable, and I would ensure to modulate driving speed to ensure to arrive at the SC with 5-10%. Recent roadtrips have been done the same, but I target 15-20% and cross my fingers that I don't get a shut down at those SOC.

So it's obvious that you have been reading a lot and you take meticulous care of your battery to follow the knowledge that you have learned on the forums and other places.

Stop doing that!

Just drive the car. Periodically take a long trip and charge it to 100% (and let it sit for hours).

i.e. follow Tesla's advice and not that of the armchair battery experts.

Stop babying the battery!

 

[gaspi101]

yeah it would be good to log bms data with SMT near that shutdown point to see whats happening
normally if imbalance or such happens it should throw an error.. so its strange..
i wonder if maybe fast acceleration caused voltage sag n tripped min V for shutdown...(don't know what it is)
does anyone know if car limits power at some low SOC?
i've only ever driven once to 5% but never gave it a punch
Out of spec reviews always say cars power gets limited when they get close to zero but i don't recall exactly when...

I was on the highway doing 70, about 2 miles from the supercharger, no warnings. Then the car suddenly said "Car shutting down for insufficient charge, pull over safely," or something similar, and a repeating chime...on the 6% shut down I was able to coast with no acceleration at all (it was a late night, no traffic, took a red light to not lose momentum), and then pushed the car the last block into the SC with some help from good samaritans. The 3%, I was alone, and that sucked. A Corolla pushed me up the ramp to a gas station to plug in the wall for a few hours, and was then able to limp the last mile to the supercharger.

 

[gaspi101]

So it's obvious that you have been reading a lot and you take meticulous care of your battery to follow the knowledge that you have learned on the forums and other places.

Stop doing that!

Just drive the car. Periodically take a long trip and charge it to 100% (and let it sit for hours).

i.e. follow Tesla's advice and not that of the armchair battery experts.

Stop babying the battery!

OK fair enough. But respectfully, I don't see how "babying the battery" was an issue here. I was just driving the car normally...the computer simply misjudged the range left and miscalculated that I could reach the supercharger in time. No bueno.

 

[E90alex]

Ok I have a bone to pick with the Tesla apologists here. If we are driving the car as recommended and charging as recommended, it is absolutely unforgivable to have a system that tells you you have 6% battery left and then suddenly die on the highway. I’d like to think I’m a highly-tech saavy individual, make sure to do a BMS calibration at least one a month, charge every 3-4 days to get readings at different stages between 20% and 85%, monthly charge it to 95% and let it sleep for 30 min before driving, etc. It’s work to think about all of this.

I agree that it is unforgivable that the car dies before 0% indicated. Somehow the BMS is out of whack.

How much do you drive? I believe this issue happens most in cars that are driven a lot and it never gets a chance to rest/sleep so the BMS can take readings.

What exactly do you mean by doing a BMS calibration at least once a month? In any case that seems excessive.

Charging to 95% every month isn’t doing anything more than charging to 85%. You need to charge to 100% (and wait until there is zero power draw) and let it sit asleep once finished for a couple hours or so. That lets the BMS balance the cells and learn true 100% capacity. But also should not need to do that every month. Maybe once or twice a year should suffice.

Also have to ensure when it’s parked/sitting at home that you don’t have sentry mode or summon standby on. The BMS won’t get a reading if the car is “in use” in any way. I also leave sentry mode off at work so the BMS can get a reading while parked at work.

 

[gaspi101]

I agree that it is unforgivable that the car dies before 0% indicated. Somehow the BMS is out of whack.

How much do you drive? I believe this issue happens most in cars that are driven a lot and it never gets a chance to rest/sleep so the BMS can take readings.

What exactly do you mean by doing a BMS calibration at least once a month? In any case that seems excessive.

Charging to 95% every month isn’t doing anything more than charging to 85%. You need to charge to 100% (and wait until there is zero power draw) and let it sit asleep once finished for a couple hours or so. That lets the BMS balance the cells and learn true 100% capacity. But also should not need to do that every month. Maybe once or twice a year should suffice.

Also have to ensure when it’s parked/sitting at home that you don’t have sentry mode or summon standby on. The BMS won’t get a reading if the car is “in use” in any way. I also leave sentry mode off at work so the BMS can get a reading while parked at work.

Thanks...For full disclosure, I'm very much up to speed on proper charging habits and balancing of BMS. I've was engaged and reading on this issue since 2018 (you might see some reddit threads from 6+ years ago from me, I wrote a lengthy tutorial on the issue)...I appreciate the tips, but let's assume for the moment that this is not "user error." Cars sleep at home 15 hours+ per day, roadtrips with 100% starting charge and 2-hour sleep cycles at 100% maybe once a month...and you're wrong that charging to 95% doesn't help the BMS calculate better than at 85%. According to the white-papers, anything above 90% will give the BMS an accurate top-end kWh reading. And doing it once or twice a year is certainly not enough, as the BMS gets out of whack in terms of estimates at different times depending on charging schedules. If you drive 10% a day, and charge only 60 to 70% at home for a continuous month, you're going to have a very skewed reading on the rated mile estimate.

 

[AlanSubie4Life]

Thanks...For full disclosure, I'm very much up to speed on proper charging habits and balancing of BMS. I've was engaged and reading on this issue since 2018 (you might see some reddit threads from 6+ years ago from me, I wrote a lengthy tutorial on the issue)...I appreciate the tips, but let's assume for the moment that this is not "user error." Cars sleep at home 15 hours+ per day, roadtrips with 100% starting charge and 2-hour sleep cycles at 100% maybe once a month...and you're wrong that charging to 95% doesn't help the BMS calculate better than at 85%. According to the white-papers, anything above 90% will give the BMS an accurate top-end kWh reading. And doing it once or twice a year is certainly not enough, as the BMS gets out of whack in terms of estimates at different times depending on charging schedules. If you drive 10% a day, and charge only 60 to 70% at home for a continuous month, you're going to have a very skewed reading on the rated mile estimate.

Could ask @wk057 - I think he has said this is a bad sign.

If estimation issue as @AAKEE suggests you should see massive downward adjustments when you park and sleep after a 90% to ~20% discharge (continuous, no adjustments).

What seems like should happen if this consistently adjusts is the BMS should knock some miles off your pack capacity (about 8-10% in this case). So reduce 100% charge by 20 miles - problem solved. I suspect more complicated though.

 

[ewoodrick]

OK fair enough. But respectfully, I don't see how "babying the battery" was an issue here. I was just driving the car normally...the computer simply misjudged the range left and miscalculated that I could reach the supercharger in time. No bueno.

You actually weren't doing what you thought to the battery. It was probably more confused than anything else.

Tesla has NEVER said that charging to 100% is bad, to the contrary, it is suggested for longer trips. But you were "babying" your battery and not doing it.
I'm not saying that this would solve your situation, but what you are doing certainly isn't.
If beating your head against the wall hurts, then stop doing it.

You may have been driving the car normally, but you weren't charging it normally.

I've seen one or two posts over the years where a car has run out of battery earlier than expected. So it is indeed possible, but seemingly rare. As well as I can remember the other gentleman had unique charging regimen and ran near 0 many times.

 

[brainhouston]

U do realize that most ppl drive the their cars n don't follow any charging/balancing habits, besides what car tells them, 80% vs 100% for trips...
And how many do u think have issues with not getting to 0%?... very few, otherwise this forum n other interwebs would be blowing up

Something is up with ur battery, it drops off the the bottom of SOC faster than normal is my guess so BMS can't predict..
Think of it as the cellphones that shut off in cold at like 30-40%, something like that in my opinion...

I've driven my car for 1.5 yrs/11k miles, never charged to 100% n only handful of times above 90%, i've got it down to 5% once n many times below 10%
It never shut off on me.
I bet its the same for most ppl

 

[ucmndd]

Thanks...For full disclosure, I'm very much up to speed on proper charging habits and balancing of BMS. I've was engaged and reading on this issue since 2018 (you might see some reddit threads from 6+ years ago from me, I wrote a lengthy tutorial on the issue)...I appreciate the tips, but let's assume for the moment that this is not "user error." Cars sleep at home 15 hours+ per day, roadtrips with 100% starting charge and 2-hour sleep cycles at 100% maybe once a month...and you're wrong that charging to 95% doesn't help the BMS calculate better than at 85%.

Battery hocus-pocus and balancing sorcery claims aside… you have a bum pack. Good news is it will probably fail soon enough and you’ll get a new one.

Were I you if probably keep exacerbating the issue on purpose. Keep running it low and letting it die. Force their hand.

 

[AAKEE]

Lithium plating causes the OCV Voltage to not drop as fast as normal efter a charging session.
The SOC can not be measured during a charge either. The energy needed to hit the SOC target need to be calculated, and the end result SOC need to be measured.

If the OVC has shifted upwards for a long enough time it might fool the BMS about the SOC being higher than the real value.

I did not find the research report I was looking for, but here’s a picture from another report.
Blue = voltage drop without lithium plating
Red = voltage drop with lithium plating

This doesnt have to be the explanation but it could possibly be a part of it.

 

[E90alex]

Thanks...For full disclosure, I'm very much up to speed on proper charging habits and balancing of BMS. I've was engaged and reading on this issue since 2018 (you might see some reddit threads from 6+ years ago from me, I wrote a lengthy tutorial on the issue)...I appreciate the tips, but let's assume for the moment that this is not "user error." Cars sleep at home 15 hours+ per day, roadtrips with 100% starting charge and 2-hour sleep cycles at 100% maybe once a month...and you're wrong that charging to 95% doesn't help the BMS calculate better than at 85%. According to the white-papers, anything above 90% will give the BMS an accurate top-end kWh reading. And doing it once or twice a year is certainly not enough, as the BMS gets out of whack in terms of estimates at different times depending on charging schedules. If you drive 10% a day, and charge only 60 to 70% at home for a continuous month, you're going to have a very skewed reading on the rated mile estimate.

I use 10-13% a day and charge to 50-55% daily. Have done so since I bought the car. Every 6 months or so I run down to below 20% to give the BMS more varied readings. Don’t have any issues with the BMS that I can tell. Rarely charge to 100% but did so once last year on a trip. Only sat at 100% for about 5 minutes before charging stopped which indicates cells weren’t much out of balance.

Granted I never have needed to run the battery down to single digits so I can’t say if it would die before 0%.

So either whatever you are doing is not helping the BMS or your pack is just starting to fail. There is a “reset SOC” option in the service menu but it’s not well documented what it exactly does so use at your own risk. There’s also a battery life test in service mode but not sure if that will help you either.

 

[gaspi101]

I use 10-13% a day and charge to 50-55% daily. Have done so since I bought the car. Every 6 months or so I run down to below 20% to give the BMS more varied readings. Don’t have any issues with the BMS that I can tell. Rarely charge to 100% but did so once last year on a trip. Only sat at 100% for about 5 minutes before charging stopped which indicates cells weren’t much out of balance.

Granted I never have needed to run the battery down to single digits so I can’t say if it would die before 0%.

So either whatever you are doing is not helping the BMS or your pack is just starting to fail. There is a “reset SOC” option in the service menu but it’s not well documented what it exactly does so use at your own risk. There’s also a battery life test in service mode but not sure if that will help you either.

Interesting. How do you access this menu?

 

[E90alex]

In the software menu tap and hold the car model and you’ll get a password prompt. The password is service.

Be aware you can potentially mess things up if you don’t know what you’re doing. And also if you contact service based on what you see in service mode they’ll likely just dismiss you and say service mode is only supposed to be used by trained service personnel only and they can’t/won’t help you.

 

[gaspi101]

In the software menu tap and hold the car model and you’ll get a password prompt. The password is service.

Be aware you can potentially mess things up if you don’t know what you’re doing. And also if you contact service based on what you see in service mode they’ll likely just dismiss you and say service mode is only supposed to be used by trained service personnel only and they can’t/won’t help you.

Gotcha. Ok, so will look but not mess with. Thanks.

 

[gaspi101]

You actually weren't doing what you thought to the battery. It was probably more confused than anything else.

You may have been driving the car normally, but you weren't charging it normally.

I’m sorry, what was it that I did to not charge normally?

 

[ewoodrick]

I’m sorry, what was it that I did to not charge normally?

You explained a relatively convoluted set of steps that you charge your car at. 40% here, 60%, take it low, take it high.

Normal is "Pick your max number, charge to it daily" Going on a trip, charge to 100%.

I know which one is in the Tesla manual.

 

[gaspi101]

You explained a relatively convoluted set of steps that you charge your car at. 40% here, 60%, take it low, take it high.

Normal is "Pick your max number, charge to it daily" Going on a trip, charge to 100%.

I know which one is in the Tesla manual.

If you follow the Tesla manual strictly you get an unbalanced BMS. First time discussing this issue?