Wiki Sudden Loss Of Range With 2019.16.x Software

[Ferrycraigs]

All limits on li-ion batteries are "artificial" - for the purposes of safety and longevity - starting from the very day you pick up your car. That's the entire purpose of the bloody BMS. If any aspect of the battery worsens over time - which forces the limits that have been there since the very day you picked up your car to decline - that's known as degradation.

I agree. Just the same as a car's value plummets as soon as it leaves the showroom, a battery starts degrading as soon as you start using it. For me, the crux is, that Tesla have 100% control over this. They designed the battery. They designed the BMS. They decided the level of tapering etc that was required when the car charges. They decided what was required to protect the battery from damage. If, in hindsight, they got their calculations wrong, that sits with them. If they now find that some batteries haven’t done as well as expected, that’s down to them. No doubt that’s why Elon said exactly that.

 

[Todd Burch]

Reports in the UK suggest the latest updates show 'some' recovery, a little more back each time. But I don’t want some of it back, I want all of it back. I remember I was asked to pay for all of it when I bought it.

The algorithms probably include some hysteresis, so the range would come back perhaps over a period of weeks.

 

[Ferrycraigs]

Would you rather the BMS not do its job?
If you want the BMS to do its job, do you not want it doing its job as well as possible, based on the best information available, including that accumulated after the first software release?
If information arrives later that the earlier version of the BMS should have been doing something different than it was initially programmed to be doing, do you not want it being updated to do what it should have been doing?

I'm sorry that you got bad luck with a battery whose longevity turned out to not be as good as some others. I really am. These were Tesla's first batteries with silicon in the anodes, and it became clear as soon as they started having to impose higher limitations on supercharging rates that their longevity was not holding up as well as Tesla anticipated. But the solution to the physical reactions taking place in the battery not being as good as hoped isn't "screw the BMS".

Maybe, however, you instead do want to say screw the BMS? Perhaps then Tesla should add a button, "Please tell my BMS to let me destroy my battery pack at an accelerated rate, and flag my vehicle to all potential buyers that I did this so that they know should I choose to sell it on the used market; I hereby acknowledge that I'm throwing safety and degradation to the wind"? Would that make you happy?

Karen, I find your explanations clear, plausible and knowledgable. And it makes sense if the battery is being damaged to reduce the voltage. Of course it does. But limiting the voltage has changed my battery from a 70kWh battery to a 58kWh battery. I paid extra for the higher battery because of all the benefits that brought. Tesla have previously claimed that any faults would be rectified. So if this degradation is down to the BMS not doing the job it was designed to do (and it appears to have done its job properly in the vast majority of cars) are you saying Tesla shouldn’t repair or replace, and that we should just accept that our battery wasn’t quite as good as most others?

 

[Ferrycraigs]

How so?



Please give exact quote.

I’m sure wk057 said people should probably update if they either Supercharge a lot, or charge to 100%, or both. I’m sure he didn’t say everyone should.

 

[Todd Burch]

Karen, I like you. But let’s establish facts:

1. Some percentage (let’s just say 5% for sake of argument—we don’t know the number) of customers of a certain vintage of product have suddenly lost a significant portion of range in their vehicle, while the other 95% of that same vintage have not.

2. I don’t know of anyone reporting this issue that has abused their pack. At least I know, for instance, that I rarely supercharge, I rarely charge above 90% SOC, my pack spends most of its lifetime around 65% charge, etc.

3. Battery packs are the most expensive component of the car.

4. Customers pay a lot of money for extra range.

5. Extra range is extra utility.

When 5% of customers lose a significant utility and value of the vehicle that the other 95% does not, that is not standard BMS management. That implies there is something uniquely wrong with those 5% of packs.

Now, having said that, I’m not going to jump all over Tesla and dive into a lawsuit over this. I do believe that Tesla has our safety at the front of their mind, and I will patiently wait for a software fix from them.

But Tesla should stop minimizing the issue and made a poor choice in not communicating what’s going on to affected owners. I have a 500 mile drive to do today, over mountainous terrain. I am hoping that my recent drop in range and potential Supercharging rate doesn’t affect my trip too much.

And I say that as one of Tesla’s earliest Model S customers, superfans, and someone who has a big chunk of my life savings in TSLA because I believe in the product and the mission.

 

[Ferrycraigs]

The algorithms probably include some hysteresis, so the range would come back perhaps over a period of weeks.

I still think I might wait until I see reports (from owners) that all is well.

 

[KarenRei]

Karen, I find your explanations clear, plausible and knowledgable. And it makes sense if the battery is being damaged to reduce the voltage. Of course it does. But limiting the voltage has changed my battery from a 70kWh battery to a 58kWh battery. I paid extra for the higher battery because of all the benefits that brought. Tesla have previously claimed that any faults would be rectified. So if this degradation is down to the BMS not doing the job it was designed to do (and it appears to have done its job properly in the vast majority of cars) are you saying Tesla shouldn’t repair or replace, and that we should just accept that our battery wasn’t quite as good as most others?

Personally? My view is that Tesla:

• ... should accept that it needs to communicate more clearly about what it's doing and why, rather than trying to put up a wall of silence whenever it has to do something that some people aren't going to like. These packs - while they don't violate a condition in the warranty - clearly have not lived up to the longevity standards that people expected based on other Tesla packs.
• ... should not do expensive work that's not covered by warranty, but...
• ... when it's done something that has left a meaningful number of owners feeling let down**, do the most cost effective means to try help them feel that Tesla has made up for it.

So for example, I mentioned earlier one possibility of selling replacement, modern packs at-cost, as well as doing the installation at-cost. So you end up with a car with better range and charging performance than the day you bought it.

Another possibility would be to offer discounts to people with said vehicles on new S/X so that the new vehicles are sold at-cost.

I think doing expensive work on things not covered by warranties is a bad precedent to set, but at the same time, I do think the company should try to make things up to customers some way or another when they feel let down by something. Just my take.


** - And not for a stupid reason, like the people who demand retroactive price cuts when Tesla lowers its prices

 

[Ferrycraigs]

Personally? My view is that Tesla:

• Should accept that it needs to communicate more clearly about what it's doing and why, rather than trying to put up a wall of silence whenever it has to do something that some people aren't going to like. These packs - while they don't violate a condition in the warranty - clearly have not lived up to the longevity standards that people expected based on other Tesla packs.
• Should not do expensive work that's not covered by warranty, but...
• ... when it's done something that has left a meaningful number of owners feeling let down**, do the most cost effective means to try help them feel that Tesla has made up for it.

So for example, I mentioned earlier one possibility of selling replacement, modern packs at-cost, as well as doing the installation at-cost. So you end up with a car with better range and charging performance than the day you bought it.

Another possibility would be to offer discounts to people with said vehicles on new S/X so that the new vehicles are sold at-cost.

I think doing expensive work on things not covered by warranties is a bad precedent to set, but at the same time, I do think the company should try to make things up to customers some way or another when they feel let down by something. Just my take.


** - And not for a stupid reason, like the people who demand retroactive price cuts when Tesla lowers its prices

Thank you. We may have to agree to disagree on whether the Warranty does, rather than should, cover it (perhaps that wasn’t what you meant). I see the gradual loss and over time qualifiers as exempting those situations, only. Ergo if something isn’t gradual etc. But I do agree they shouldn’t waste money paying for non warranty repairs, and I have seen many owners that I would say expect much more than is reasonable.

 

[Leeboy22001]

Mine has recovered slightly from 2019.28.2 release. Usable has gone from 46.4kWh to 47kWh !, and full pack is now 49.8kWh, was 49.2kWh. This is via ScanMyTesla, I monitor regularly, and capacity hadn't changed prior to the new software.

 

[DJRas]

You say that like that's supposed to be a shock, or like it's supposed to change anything that I wrote.

The cells are not charged to their physical maximum voltage when new, either. It's the job of the BMS to impose limits.

Every non-affected Tesla charges to 4.2 volts st 100%. Even badly degraded batteries still charge to 4.2 volts.
The BMS knows how much power is going into the pack to get to 4.2 volts, how fsst the pack voltage is rising and sdjusts current to keep the battery safe. What it never did was charge to 4.07 volts and call it 100% charged unless artificially capped (like to 75 kWh batteries but into 60 kWh cars).

 

[KarenRei]

Every non-affected Tesla charges to 4.2 volts st 100%. Even badly degraded batteries still charge to 4.2 volts.
The BMS knows how much power is going into the pack to get to 4.2 volts, how fsst the pack voltage is rising and sdjusts current to keep the battery safe. What it never did was charge to 4.07 volts and call it 100% charged unless artificially capped (like to 75 kWh batteries but into 60 kWh cars).

Reducing the max voltage is one of the easiest way to preserve longevity on cells that are showing higher-than-desired degradation. The rate of reaction between the anode and the electrolyte increases dramatically as voltages rise.

The BMS always has a limit, for safety and longevity. They simply lowered it.

Nobody is disputing that these packs have performed worse than most Tesla packs, and worse than what their owners expected of them.

 

[DJRas]

Reducing the max voltage is one of the easiest way to preserve longevity on cells that are showing higher-than-desired degradation. The rate of reaction between the anode and the electrolyte increases dramatically as voltages rise.

The BMS always has a limit, for safety and longevity. They simply lowered it.

Nobody is disputing that these packs have performed worse than most Tesla packs, and worse than what their owners expected of them.

Actually, my pack was at exactly the nominal fleet-wide degradation prior to the update. Now I am far outside of nominal. 12% beyond nominal. But Tesla's manipulation of the rated range calculation pulled my case inside of their 10% outside of nominal threshold for warranty replacement (verbally told to me threshold- would not put it in writing).

 

[Evoforce]

I still think I might wait until I see reports (from owners) that all is well.

I'm waiting for you to download the latest update before I am willing to do so! Car is begging me to do it now. Come on @Ferrycraigs you be the test rat!

 

[ChrisausHH]

Hello, my battery was reduced by the update from usable 74 kwh to 64 kwh within one hour.
The range before the update 390km, now 340 km.

Thank you very much for your efforts, DJRas

Greetings from Germany

Tesla Model S P85D 06/2015

 

[Ferrycraigs]

I'm waiting for you to download the latest update before I am willing to do so! Car is begging me to do it now. Come on @Ferrycraigs you be the test rat!

We have a saying where I come from.....

 

[Evoforce]

So the question is... does the update after 2019.24 now let us charge our battery cells back to 4.2 volts? Or if I download it is it going to make my battery capped/clipped worse and/or battery charging slower?

 

[ChrisausHH]

So the question is... does the update after 2019.24 now let us charge our battery cells back to 4.2 volts? Or if I download it it is going to make my battery capped worse?

Nope, i have 2019.28.2 and the battery is still -10 kwh.

 

[Evoforce]

Nope, i have 2019.28.2 and the battery is still -10 kwh.

Bummer... but maybe 2019.28.2.5 is the magic?

 

[willow_hiller]

Don't mean to get anyone's hopes up, but 2019.28.2.5 seems to be specifically targeted at Model S 85. Could be a coincidence it started rolling out the same day the lawsuit was filed, but that possibility of random chance decreases as each successive install is an S85.

 

[Droschke]

From electrek

"
Update: Tesla sent us the following response following the report:

“Delivering the best possible customer experience with the highest regard for safety has always been our priority, and we do not disregard either of these things as this complaint suggests. A very small percentage of owners of older Model S and Model X vehicles may have noticed a small reduction in range when charging to a maximum state of charge following a software update designed to improve battery longevity. As previously noted, we have been working to mitigate the impact on range for these owners and have been rolling out over-the-air updates to address this issue since last week.”

AFAIK no one has seen this update??

Quoting electrek:

A very small percentage of owners of older Model S and Model X vehicles

For the life of me, can't understand why this "small percentage" is such a elusive and secretive number. After all, its "small".

Quoting electrek:

A very small percentage of owners of older Model S and Model X vehicles may have noticed a small reduction in range when charging to a maximum state of charge following a software update

Losing 30 miles at 90%:
30 miles is not "a small reduction in range".
90% is not "maximum state of charge".

Quoting electrek:

"have been rolling out over-the-air updates to address this issue since last week.”

AFAIK no one has seen this update??

Not for me.