Wiki Sudden Loss Of Range With 2019.16.x Software

[Droschke]

I read of an issue on this forum of someone that was aborting his scheduled charge and hour early everyday and ran into problems. I forget what problems were, degradation or what...

@mswlogo ... If you want to change the minds of people interested in the science behind what you're talking about you need to do more than tell a good story.

Not a "good" story at all. A foggy one? May be.

 

[Chaserr]

Please stop asking me to substantiate my claims with evidence! I will report!

 

[Droschke]

@mswlogo saying to @Chaserr :

Please stop with the insults already. If you have to use insults to make your posts valid to Yourself and others it really shows your true colors.

I’m sharing what I read recently on the forum of a problem, a cause and a solution shared from his service center.

I’m ignoring you from here on because I don’t waste time with folks like you. life it to short to put up with folks like you and you only drag the community down to your level.

And I will hit report as well.

Ba bye.

@mswlogo, just read what you wrote:

I read of an issue on this forum of someone that was aborting his scheduled charge and hour early everyday and ran into problems. I forget what problems were, degradation or what ...

That ^^^ has no validity on it's own. You need to provide at least a link and more supporting evidence to convince others. And, that's what you are asked for. Otherwise, what you are suggesting is utterly baseless.

 

[JRP3]

Jason Hughes has been talking about how balancing works in the S/X batteries a few times. In a more recent post he mentioned that from the beginning to now the BMS has made leaps forward in terms of balancing. It happens all the time and is not dependent of certain charge procedures or battery levels. He mentioned he saw it getting active before the cells got out of balance, which means the system knows what will bring cells out of balance and starts counter acting right away to keep them in balance rather than waiting, measuring and then acting. All these analogies to RC batteries are meaningless. Tesla's system is on a completely different level.

Is that true of older vehicles? If the hardware was not capable of charge shuttling at lower SOC's in older cars a software update can't change that. Early BMS's in some vehicles would use bleed resistors near the top of the SOC to bleed off charge in higher voltage cells, though I don't remember if Tesla ever did that or if they always had charge shuttling capability.

 

[Droschke]

Early BMS's in some vehicles would use bleed resistors near the top of the SOC to bleed off charge in higher voltage cells, though I don't remember if Tesla ever did that or if they always had charge shuttling capability.

Assuming that's the older cars' behavior, how is it done for the newer cars? Would you be able to elaborate?

 

[lightningltd]

Because you never heard of it, it must not be true. I guess that makes it fact.

I read of an issue on this forum of someone that was aborting his scheduled charge and hour early everyday and ran into problems. I forget what problems were, degradation or what. He brought it to service and they saw errors / warning basically detecting “poor” charging. He was told stop that practice.

Made perfect sense to me and I knew better before I read it. But it helped confirm common sense.

You can do what ever you like to your battery.

It’s also been discussed in other threads that it not good to regularly abort charging.

We were not talking about 'scheduled' charging. The BMS constantly balances cells. If that were not the case, then everytime ANYONE charged for a leg on a trip and unplugged when they will have 20% on arrival would have been having issues. NO one sets the charge to stop during a trip to exactly what they will need to get to the next charger.

 

[Droschke]

Did the same to me.

Shame.

Did what to you? I've read all the replies to your posts. Which one deserves a "shame" gibe?

 

[omarsultan]

But I don’t put the blame on BMS. After all, all cars have the same software. And for, I think, the majority of cars, the BMS works just fine. It does what it says on the tin. It protects the battery from the dangers of DCFC.

I guess I am not ready to let the BMS off the hook. I am guessing battery/charge-gate will end up being some combination of:

BMS logic + battery manufacturing variance + usage patterns*

* not saying "you are using this wrong" but rather that owners have use cases, charging patterns and operating scenarios that were not envisioned or tested by the SW engineers

Considering our cars are instrumented out the wazoo, these issues should not have come as a total surprise--it seems like they finally decided to look with the last FW update.

 

[lightningltd]

I am sure that my habit of being plugged in at 110 volts 4 days a week, 10 hours a day likely keeps the cells well balanced anyways.

 

[boywonder]

Can we continue to focus our displeasure on Tesla rather than each other?

Just ignore anything you don’t agree with or question it respectfully... which is what usually happens, to be fair

 

[Ferrycraigs]

I unplug on free charge points too occasionally and take what I can get. This person was doing it every morning. He didn’t care if his battery was at target he didn’t want charge to finish early so he set it well past his leave time to assure it was charging when he left every day. Sorry I could not find the thread. Just listen to the experts here they know everything.

There are a lot of people on here, some of whom regard themselves as experts. Some are experts. I am always happy to learn new info, but I do need to see the logic normally. I’m struggling with this as the science doesn’t seem to support it. Specifically the BMS identifies how much is going in, how hot that is making the battery and adjusts so that Vmax isn’t exceeded or the max sustainable temp isn’t exceeded. I have always assumed that process is dynamic throughout the charge cycle. Perhaps it isn’t, but I can’t see why it wouldn’t be. But if I’m doing it wrong, it would be good to know why.

 

[Droschke]

Can we continue to focus our displeasure on Tesla rather than each other?

Just ignore anything you don’t agree with or question it respectfully... which is what usually happens, to be fair

They are questioned respectfully.

 

[omarsultan]

There are a lot of people on here, some of whom regard themselves as experts. Some are experts. I am always happy to learn new info, but I do need to see the logic normally. I’m struggling with this as the science doesn’t seem to support it. Specifically the BMS identifies how much is going in, how hot that is making the battery and adjusts so that Vmax isn’t exceeded or the max sustainable temp isn’t exceeded. I have always assumed that process is dynamic throughout the charge cycle. Perhaps it isn’t, but I can’t see why it wouldn’t be. But if I’m doing it wrong, it would be good to know why.

I could see the logic in BMS not bothering to balance until the pack is closer to full--why bother balancing at, say, 50% SoC. If balancing is a final step at higher SOC, I can see that unplugging early would short circuit that (forgive the pun)

 

[lightningltd]

Back to the topic at hand, #BatteryGate and #ChargeGate:
With the new version of firmware supposedly able to better detect 'degradation, has anyone who has an infected battery seen the firmware start to reverse the removal of the limits yet, or do we think that they firmware is only able to detect but not reverse the prior changes if the 2019.16.x acted too hastily?

 

[Droschke]

to better detect 'degradation

Not "degradation", please

It apparently, based on what's being reported, tags the critically sick batteries for possible replacement. That's all it's doing. The sick batteries, such as yours and mine, will stay in the band-aided status (non-reversible capped) till either our warranties expire or become the become critically sick to be tagged for possible replacement. That' how I understand it so far.

 

[TJtv]

Back to the topic at hand, #BatteryGate and #ChargeGate:
With the new version of firmware supposedly able to better detect 'degradation, has anyone who has an infected battery seen the firmware start to reverse the removal of the limits yet, or do we think that they firmware is only able to detect but not reverse the prior changes if the 2019.16.x acted too hastily?

Early indications seem to imply that this new firmware has no ability to detect that previously capped cars are actually-ok and restore them back to normal. However, the new firmware does appear to be able to determine that some of the capped cars were more critically damaged than was previously estimated and those cars are being flagged with a failing battery message and being told to bring the car in for a battery swap:
Maximum battery charge level reduced

 

[JRP3]

Assuming that's the older cars' behavior, how is it done for the newer cars? Would you be able to elaborate?

Modern BMS will shuttle charge from higher cells to lower instead of just bleeding off through resistors. Apparently they can do this throughout the SOC range instead of waiting for a higher SOC to be reached.

 

[AmpedRealtor]

"to prevent sudden and significant loss of range" ???

Unless the pack is capped by Tesla, how can the pack suddenly lose significant range by itself?

A failure of one or more modules can cause sudden range loss. What would cause a module to fail, or how it fails, is beyond my understanding.

 

[omarsultan]

Back to the topic at hand, #BatteryGate and #ChargeGate:
With the new version of firmware supposedly able to better detect 'degradation, has anyone who has an infected battery seen the firmware start to reverse the removal of the limits yet, or do we think that they firmware is only able to detect but not reverse the prior changes if the 2019.16.x acted too hastily?

It certainly did not help me - 40.2 knocked my theoretical* 100% from ~220 to ~205 rated miles.

 

[mswlogo]

I could see the logic in BMS not bothering to balance until the pack is closer to full--why bother balancing at, say, 50% SoC. If balancing is a final step at higher SOC, I can see that unplugging early would short circuit that (forgive the pun)

I don't think balancing is only done at high SOC. But it could/may do balancing during different phases of the charge plan and if you abort the charge say 10% short of the target every time you may mess things up. I'm sure the BMS doesn't do everything based on "instantaneous" measurements. It does things based on trends and past history. Possibly it messes up things for the next charge because the prior one never completed. Maybe it does some record keeping at the end of a complete charge and that never gets done. I don't know the details but it made perfect sense to me that it could be bad.