Wiki Sudden Loss Of Range With 2019.16.x Software

[qwk]

I believe this is the smoking gun proof of why Batterygate caps are implemented everyone has been looking for. This is 92% SOC on a car showing 100% 4.2v strings. If this battery was charged to 100% and left parked for a week or two, these cells would heat up and eventually cause a fire.

I don't know if this is @wk057's condition X or not but this is dangerous and if it has happened in multiple cars there should be an immediate recall.

This was obviously taken while the car was actively charging. One cannot come to any conclusion with just this screenshot.

 

[supratachophobia]

That is my understanding too. So do individual cells get balanced by some technical means right throughout the charge cycle at all states of charge or does cell balancing by implication have to be take place during the constant current phase?

There is something called a bleed resistor that can balance a brick within a module. The brick's full charge voltage is 4.2v because it's a bunch of cells in parallel. Those bricks are then wired in series to give a module voltage of 25v, then those are wired in series again to give you your 400v pack voltage. At least, that's how I think it works. So not quite at the cell level for charge control, but close.

 

[David99]

You have 265K miles on your original battery???? Mines about 3 mv at 90% and 10mv at 10% so nearly the same as yours with 107K miles on my battery. In fact, if it wasn't for module 58, I'd only have a 2mv difference at 90% and 4 mv difference at 10%.

Yes 265 k miles and I was unaffected until around 240k miles. Then they got me. The good part of this is that I have been doing lots of CAN bus logging before and after I got limited so my data helped make the case for David.

My cell balance hasn't really changed with age. Maybe a very small amount. Tesla's BMS is phenomenal. What is happening here isn't in any way the fault of the BMS. Considering the high use/age the cells are doing awesome, but eventually they just give in.

 

[David99]

This was obviously taken while the car was actively charging. One cannot come to any conclusion with just this screenshot.

I was going to say the same. It is the #1 mistake that happens when looking at cell balancing. You cannot get a correct reading through the CAN bus as long as there is a load on the battery (charging or discharging). Based on my experience, it is necessary to wait about 10 min to let the cells settle to get a good reading. TM-Spy has a graph that is very interesting in that context. When there is a constant load on the battery, for example while supercharging, you can see a wave pattern in the cell voltages. I don't have a definite explanation for this, but one way or another, This shows well that you not getting a usable reading for cell balance while any load is on the battery!

 

[omarsultan]

Now, this is a pack that has some serious imbalance issues. At 74% SOC and under light to no load. I see about 4 kW being draw, was the HVAC on? Would be nice to get a snapshot with as little load as possible.

Still - there is one module 95 mV lower than the peak - the only time you should see that kind of difference is down near empty (< 20% SOC), or possibly on a well-used pack under heavy load. And not just one module is low, but there's 3 other modules pretty low as well - 50-60 mV low.

This is one seriously out of balance pack. Really would be nice to see cell voltages at 100% and near 0% as well.

IMO this pack has modules that have failed and should be refurbished.

Does anyone have a cell or pack -voltage / SOC chart for Tesla cells? You could then estimate just how much capacity is being lost due to these weaker modules when you see a snapshot like this. Based on some charts I've looked at, the difference between 3.85 and 3.95V is around 10%.

Thanks @Dave EV -- here are grabs from the car with everything turned off (the door was open and heat running last time). I'll charge to ~100% tonight and report back.

 

[Dave EV]

Thanks @Dave EV -- here are grabs from the car with everything turned off (the door was open and heat running last time). I'll charge to ~100% tonight and report back.

View attachment 498870 View attachment 498871

No real change in reported voltages (they are slightly higher), so the bit of load that the heater put on the pack didn't change the picture. This is still one of the worst balanced packs I've seen.

It would be interesting to see the voltages at various SOC if it's convenient.

I suspect that if you deep cycle the pack a number of times, the BMS will eventually throw an error code and you'll get a replacement pack. Out of curiosity, what's your typical charging routine?

I found this post of yours: 7 years later what is your 100% on your 85kWh battery?

Your car also only charges to 95%, too? I suspect it's the huge imbalance that's causing this. Makes me wonder if there's some BMS gremlins that are causing Tesla to cap these batteries as well when the modules become significantly unmatched.

 

[Ferrycraigs]

The vMax as displayed is the highest voltage of your battery. Not your maximum allowable charge - that should be 4.2v, except it isn't if your battery is artificially capped. You have to charge all the way to 100% and see if vMax comes close to 4.2v in order to confirm you have been capped or not.

I thought that Vmax WAS the max allowable charge, and that was what Tesla changed to stop the max charge at a revised 4.1V etc. I have TMSpy and so I get that screenshot on mine. I always read that screenshot as showing the max and min voltage at that given SoC%, ie just the spread at that particular point. So the wide screen shows it brick by brick, and the narrow screen is just a summary. If Omar's Vmax is only 3.9V he’s in deep doo doo!

I may have to delve back into the notes, which aren't as clear as they might be.

 

[boywonder]

Currently running 2019.36.2.7 with 2019.40.2.3 waiting to be installed.

Battery is already capped by 2019.16.x

Is 2019.40.2.3 likely to cripple or make my car worse?

 

[Ferrycraigs]

Currently running 2019.36.2.7 with 2019.40.2.3 waiting to be installed.

Battery is already capped by 2019.16.x

Is 2019.40.2.3 likely to cripple or make my car worse?

Even Tesla say 2019.40.2.2 is likely to make your AP worse (particularly Auto Lane Change). It now makes me nervous when the Release Notes for 40.2.3 say it allows Tesla to “improve our ability to detect High Voltage Battery performance degradation”. Some months age I would have read that as something positive. I now wonder if that just means more opportunity for them to strangle me a bit more.

 

[liamharry]

I believe this is the smoking gun proof of why Batterygate caps are implemented everyone has been looking for. This is 92% SOC on a car showing 100% 4.2v strings. If this battery was charged to 100% and left parked for a week or two, these cells would heat up and eventually cause a fire.

I don't know if this is @wk057's condition X or not but this is dangerous and if it has happened in multiple cars there should be an immediate recall.

Is this not a screenshot from the battery info page of the Tesla Service diagnostic access on the MCU? Be interesting to know how you got access.

 

[dark cloud]

Even Tesla say 2019.40.2.2 is likely to make your AP worse (particularly Auto Lane Change).

It should be noted only because of the region you are in; no change for me in Canada (and I assume all of North America)

 

[Ferrycraigs]

It should be noted only because of the region you are in; no change for me in Canada (and I assume all of North America)

Indeed. Helpful hopefully for Boywonder as he’s from London (I assume the real one).

 

[boywonder]

Even Tesla say 2019.40.2.2 is likely to make your AP worse (particularly Auto Lane Change). It now makes me nervous when the Release Notes for 40.2.3 say it allows Tesla to “improve our ability to detect High Voltage Battery performance degradation”. Some months age I would have read that as something positive. I now wonder if that just means more opportunity for them to strangle me a bit more.

Thanks I’ll try to avoid installing it for as long as I can then.

 

[TJtv]

Not at all. When charging a Lithium battery you will reach the maximum and then reduce the charge current while continuing to charge. The cell isn't full when the 4.2 limit is reached during charging. It is full when the charge current is practically zero and the cells are at 4.2. During normal charging at 10 kW. The cells reach the max at just under 90% and then stay flat until 100 % is reached. When charging at higher power you reach the max even earlier. It's Lithium battery charging 101.

Totally agree with you if the picture was taken while car was charging. That’s a very misleading thing to post.

 

[Ferrycraigs]

Thanks I’ll try to avoid installing it for as long as I can then.

Snap.

I’m sure the old adage of 'if it ain't broke...’ may apply here.

 

[dark cloud]

Keep in mind that 2013 S's often made it to 200K miles or more on the original battery on v8 or earlier. Some of those with frequent supercharging. Whatever went into their decision making to limit charge range on 85s that include 2015s is either because of a possible safety concern or more likely an attempt to lower their warranty costs from having to replace 5% of the battery down to say 1% (or whatever those numbers really are).

I'm still on 8.1 and therefor not effected. My Ludicrous upgraded P85D has seen 107K miles of spirited driving with 303 wh / mile lifetime efficiency, 13 miles of lost range, and supercharging speeds close to what they were when new.

And I am curious as hell to find out what is going to happen long term.

Are we (the ones who updated) all going to continue to get reduced supercharging rates, and decreased range in the name of (apparently) safety? While you might be at 200,000 miles in a few years and still be able to claim the same?

Or will you have a battery issue, one that you have no battery warranty for because you didn't update, and if it is catastrophic in nature, and possibly if it burns other things down with it, maybe your house, you quite possibly may have no house or liability insurance for either because you are purposefully engaging in risky behaviour, or neglected maintenance, or however the insurance companies contracts word it where ones actions increased risk beyond what someone is normally expected to do to reduce risk. (Comparable to if someone has a windstorm and the wind and rain causes tens of thousands of dollars damage, but the insurance company discovers you have a 50 year old shingle roof with 30 year warranty shingles, they deny the claim because you should have replaced the 30 year life expectancy roof 20 years previously.)

But if you don't charge to high levels and let it sit, because we now understand the situation (I think), is it going to be ok? Is that the only reason the batteries are spontaneously combusting?

Are we now sure this whole issue is about the risk for consumers to blow up the battery? Or a conspiracy to prolong a few thousand batteries to beyond the warranty period?


If we all promise in writing to not ever charge to 100% or store the car at anything higher than 90% could they bring back the faster supercharging rates and higher capacity? Or is it another case of a few idiots ruining it for everyone else.

 

[Ferrycraigs]

And I am curious as hell to find out what is going to happen long term.

Are we (the ones who updated) all going to continue to get reduced supercharging rates, and decreased range in the name of (apparently) safety? While you might be at 200,000 miles in a few years and still be able to claim the same?

Or will you have a battery issue, one that you have no battery warranty for because you didn't update, and if it is catastrophic in nature, and possibly if it burns other things down with it, maybe your house, you quite possibly may have no house or liability insurance for either because you are purposefully engaging in risky behaviour, or neglected maintenance, or however the insurance companies contracts word it where ones actions increased risk beyond what someone is normally expected to do to reduce risk. (Comparable to if someone has a windstorm and the wind and rain causes tens of thousands of dollars damage, but the insurance company discovers you have a 50 year old shingle roof with 30 year warranty shingles, they deny the claim because you should have replaced the 30 year life expectancy roof 20 years previously.)

But if you don't charge to high levels and let it sit, because we now understand the situation (I think), is it going to be ok? Is that the only reason the batteries are spontaneously combusting?

Are we now sure this whole issue is about the risk for consumers to blow up the battery? Or a conspiracy to prolong a few thousand batteries to beyond the warranty period?


If we all promise in writing to not ever charge to 100% or store the car at anything higher than 90% could they bring back the faster supercharging rates and higher capacity? Or is it another case of a few idiots ruining it for everyone else.

Of course the battery Warranty on the older cars does not require you to update the firmware. That’s a new revision that will not apply to older cars. So at least our Warranty should not depend on what version of firmware we are on.

 

[Brando]

Washington Post Today:

“My belief is that Tesla is more willing to risk their battery not lasting 8 to 10 years and just dealing with the consequences on the back-end,” said Michael Ramsey, a senior director and analyst specializing in the evolution of the auto industry with Gartner’s CIO Research Group. “Part of their success is related to their willingness to go way past what the industry would normally would do,” he said.

https://www.washingtonpost.com/technology/2020/01/10/tesla-battery-range/

How much of a factor is simple FUD??

Tesla seems to collect/monitor a massive amount of data from their vehicles. Battery use/charge/discharge/environment a complex amount of variables and I would suspect Tesla has more data points than most anyone else.
8 year warranty meant Tesla took on much of the risk. I still appreciate early adopters contribution to take on the risk of something new. At least the cars were safe & beautiful & fun/interesting to drive.

 

[dark cloud]

Of course the battery Warranty on the older cars does not require you to update the firmware. That’s a new revision that will not apply to older cars. So our Warranty should not depend on what version of firmware we are on.

I am hoping I am wrong on this: Maybe if I get time I can check the original warranty wording using way back, or does someone else have it handy to post?

 

[Ferrycraigs]

I am hoping I am wrong on this: Maybe if I get time I can check the original warranty wording using way back, or does someone else have it handy to post?