Pack Performance and Launch Mode Limits

[Ingineer]

ING,
Is Tesla signing BMS updates? I was surprised that they were not doing this from the start and am curious if they have initiated the practice.

For those not familiar with the term......
Signing Files
This is a technique used by OEMs (and others I am sure) where by new software updates are checksummed (RipeMD160 being a Bosch favorite). The newly updated code is then checksummed and compared with an RSA encrypted message containing the proper unmodified checksum. If they agree, the code is allowed to run. If not, brick. The public key is in the module being updated but the private key needed to encrypt a valid checksum is not so you can not generate messages that enable your modified software updates to take.

The solution is physically attaching a Background Debugging Module to the target board and brute force over writing the existing code.

They are signing all code with a highly secure ECDSA system. The gateway verifies each systems firmware file using this before it will flash the target system. It is still possible to flash a target module with physical access, but it is no longer possible to remotely load unsigned firmware in any system other than the CID and IC itself. The gateway also checks the signatures on any code for itself, so it is no longer possible to roll back to version before the signing started (2.36.31). That was the old-style 7.1 GUI, so at least we have one version of 7.1 that can be run if desired.

 

[drewsny]

So just checked my manual in my P85DL and it has the added bit about tracking the use of launch mode, which leads me to believe this might affect P85Ds with the ludicrous upgrades. Someone give me a good reason why I shouldn't call tesla right now and ask for my 5k back.

 

[Zhelko Dimic]

This viewpoint has been heavily influenced by the hype train. The reality is that the basic drive unit in the back of all rwd and all P cars is roughly the same as it was in 2012. There have been many small improvements but Tesla engineers know it's limits and they know that the current (no pun intended) power level of the L models and P100, will push an already weak link.

This idea that the old "ICE" OEMs are stodgy and don't innovate and that's why they can back up their advertised performance with a warranty is nonsense. Most ICE engine platforms have seem more change in architecture with GDI and turbocharging in the last 4 years than Tesla. And they still manage to determine durability BEFORE they sell to customers.

This hyped narrative that all Tesla's problems are a result of them just being too innovative to conform to the backwards industry is tailored for people who don't know much about said industry.

Oh, c'mon, Porsche has good reputation and every Porsche generation has some serious issue.
Air cooled cars: all need top-end rebuild for one or another reason, with less than 100K
All '99-07, except Turbo and GT3: cylinder scoring and IMS (LOTS of dead engines)
Turbo and GT3: sudden coolant/hose failure, such that Porsche clubs demand you to pin all hoses before they let you on the racetrack $3-4K; to not spray racetrack with coolant and cause accidents, I've seen one in front of my eyes, and had failure happen to me - twice
991 and newer model: something is broken, we just don't know what's that yet

 

[bhzmark]

“Like other automakers, our performance vehicles continually monitor the condition of various components and may employ limiting strategies to reduce fatigue on the powertrain.”

When Tesla starts a sentence with "Like other automakers, our..." you know the rest of the sentence is not good.

 

[MP3Mike]

It is surprising to me that while launching too often will damage the drive train, why would upgrading to a more powerful battery (P100D) allow unlimited launches, instead of doing even more damage?

I assume the damage is actually being done to the battery, which is why the counter is in the battery, and not the rest of the drive train. The 100 kWh battery is completely redesigned so that it doesn't get damaged during high-power launches.

 

[drewsny]

I assume the damage is actually being done to the battery, which is why the counter is in the battery, and not the rest of the drive train. The 100 kWh battery is completely redesigned so that it doesn't get damaged during high-power launches.

Seems like there's an easy fix here. Either upgrade owners batteries at a reduced cost, maybe 10k and keep the batteries to put into service or refurbishment. Or to just refund the owners for the full price of ludicrous mode.

 

[u00mem9]

Oh, c'mon, Porsche has good reputation and every Porsche generation has some serious issue.
Air cooled cars: all need top-end rebuild for one or another reason, with less than 100K
All '99-07, except Turbo and GT3: cylinder scoring and IMS (LOTS of dead engines)
Turbo and GT3: sudden coolant/hose failure, such that Porsche clubs demand you to pin all hoses before they let you on the racetrack $3-4K; to not spray racetrack with coolant and cause accidents, I've seen one in front of my eyes, and had failure happen to me - twice
991 and newer model: something is broken, we just don't know what's that yet

I think you made the point that Porsche does NOT have a good reputation!

 

[FlatSix911]

I assume the damage is actually being done to the battery, which is why the counter is in the battery, and not the rest of the drive train. The 100 kWh battery is completely redesigned so that it doesn't get damaged during high-power launches.

Correct ... an incentive to upgrade
Tesla confirms that it limits the power of performance vehicles after too many launches with ‘launch mode’

As for this power limiting issue, a source familiar with the problem told Electrek that the company is working on better communicating the situation to its owners. It appears to only affect P90D vehicles (at least the affect was only reported on P90Ds but other dual motors could have a launch counter) and the solution is apparently an expensive upgrade to a 100 kWh battery pack, which is coming next year, since Tesla’s latest top-of-the-line P100D model is apparently not affected by the problem.

 

[Zhelko Dimic]

Another, quite significant, difference is that Nissan was completely open about what they were doing. Tesla has been, shall we say, less than completely open about this.

Additionally, Nissan wasn't making the change to existing owners' cars over the air. The cars had to be brought in for service.

These are pretty significant differences.

Huh, not sure where you get your data? After GT-R issues started, it took couple of years before Nissan admitted what's going on, issued fix that is actually reducing power (had to go the the service), and there are number of people that have paid $30K for blown transmission that never got money back. Check that Yalopnik article again.

I'm gonna go here with:

Tesla sucks less!!!

 

[HebrHmr]

So just checked my manual in my P85DL and it has the added bit about tracking the use of launch mode, which leads me to believe this might affect P85Ds with the ludicrous upgrades. Someone give me a good reason why I shouldn't call tesla right now and ask for my 5k back.

I think they're generic. The picture I posted is off my P100DL which everyone seems to agree isn't affected.

 

[Andyw2100]

So just checked my manual in my P85DL and it has the added bit about tracking the use of launch mode, which leads me to believe this might affect P85Ds with the ludicrous upgrades. Someone give me a good reason why I shouldn't call tesla right now and ask for my 5k back.

Because they won't give it to you.

But if you do call, you can also ask them for your 691 HP. Of course you won't get that either, but...

 

[brianman]

As for this power limiting issue, a source familiar with the problem told Electrek that the company is working on better communicating the situation to its owners. It appears to only affect P90D vehicles (at least the affect was only reported on P90Ds but other dual motors could have a launch counter) and the solution is apparently an expensive upgrade to a 100 kWh battery pack, which is coming next year, since Tesla’s latest top-of-the-line P100D model is apparently not affected by the problem.

What a cluster. Ever since the first P85D was delivered, Tesla has been on its heels delivering on the promises made for that vehicle. Will the P100D finally do it? Odds are looking better that I'll have my second Model 3 before the issue is resolved.

 

[Walta]

I assume the damage is actually being done to the battery, which is why the counter is in the battery, and not the rest of the drive train. The 100 kWh battery is completely redesigned so that it doesn't get damaged during high-power launches.

Thanks... I wasn't thinking the drive train included the battery.

 

[Garlan Garner]

@Andyw2100 already answered the not knowing part. The P90DL buyers did not know about this limit beforehand. Not buying is not an option when you did not and reasonably could not have known.

The second part is the relative impact. Boycotts aside, I would say very few products and/or companies on/off, yes/no decisions. There are shades of grey where customer feedback and conversation is one response.

You know perfectly well there are no other long range EVs available. Not all issues are reasons enough to forgo that. Some are just feedback.

Most people that have a Tesla bought one because they wanted a Tesla. Period.

Just like I put the down payment on a M3 18 months before it will get delivered to the first customer.

I'm fully aware that there are going to be people who say the same thing about the M3 - even if it was delivered right now. "Tesla didn't tell me xyz or ABC'".

 

[Tech_Guy]

Still upset about this.... Hmm so they added it to the manual now, great... By the time I picked up my car in June I had read that thing front to back, there was no warning about launch mode, also went though the in car manual a few times and there was no warning... Just so disappointing to discover this, though I'm happy we can prevent it for other owners and that there is now a listed warning, Its something that should have been listed and provided with my NEW car... Unfortunately I found this out the hard way and have no chance to prevent the damage so basically I'm punished for discovering something that tesla should have told us about.... Thats quite a sour taste in my mouth Tesla did Too Little Too Late for me!!! I took delivery 6 months ago and NOW they add this to the manual?!

Oh ya and UNLIKE THE EMAIL I RECEIVED I don't see any mention of the P100DL being excluded from this limitation in the manual so BUYER BEWARE!!!

 

[lolachampcar]

Just keep in mind that the limit appears to be reducing 1600ish amps from the battery to 1500ish amps. NO P85DL was allowed 1600ish amps which tells me they will not experience a roll back (because we are already there).

Do keep in mind that Tesla made changes to the cooling AND battery interconnect with the 100 (likely among other changes). They apparently addressed the 1600ish problem and made a decision to NOT do a P85D to L style field upgrade. Given the distraction that program was/caused, I can understand why they would like to avoid it. They have also made a decision not to battery swap the problem away. The only option left is to determine just how much abuse the battery can take then cap its high amp use below that threshold.

Lastly, people keep writing about drive line weakness. This may be the case but, logically, all indications point to a battery weakness and nothing more. Ing speculated exactly the way I would have addressed the issue. Specifically, the first X time period is "free" in that the thermal inertia of the interconnects allow for a short period of high amperage use before deterioration begins (or skin charge in the cell allows for very short high C discharge without damage if it is a cell issue). If you exceed that time, a counter then tracks the exposure. Once the limit is reached, the 1600ish amp stress if removed forever. This is the most logical explanation. I think it is also worth noting that, if it is a cell issue, the counter would only function at higher SoCs while, if it is an interconnect issue, it should function all the time (1600ish is 1600ish without regard for the SoC).

The only way we are going to know is if someone throws the BMS code into IDA

 

[Walta]

Just keep in mind that the limit appears to be reducing 1600ish amps from the battery to 1500ish amps. NO P85DL was allowed 1600ish amps which tells me they will not experience a roll back (because we are already there).

Do keep in mind that Tesla made changes to the cooling AND battery interconnect with the 100 (likely among other changes). They apparently addressed the 1600ish problem and made a decision to NOT do a P85D to L style field upgrade. Given the distraction that program was/caused, I can understand why they would like to avoid it. They have also made a decision not to battery swap the problem away. The only option left is to determine just how much abuse the battery can take then cap its high amp use below that threshold.

Lastly, people keep writing about drive line weakness. This may be the case but, logically, all indications point to a battery weakness and nothing more. Ing speculated exactly the way I would have addressed the issue. Specifically, the first X time period is "free" in that the thermal inertia of the interconnects allow for a short period of high amperage use before deterioration begins (or skin charge in the cell allows for very short high C discharge without damage if it is a cell issue). If you exceed that time, a counter then tracks the exposure. Once the limit is reached, the 1600ish amp stress if removed forever. This is the most logical explanation. I think it is also worth noting that, if it is a cell issue, the counter would only function at higher SoCs while, if it is an interconnect issue, it should function all the time (1600ish is 1600ish without regard for the SoC).

The only way we are going to know is if someone throws the BMS code into IDA

This is the part I do not understand. Where after X times using launch mode at 1600 amps causes damage but launching unlimited times at 1600 amps doesn't ? When empirical testing shows no measurable difference in track results between using launch mode and just mashing the accelerator. So if that is truly the case there must be some difference in instantaneous current drawn between the two methods that can't be recreated when not using launch mode? Did the people who reported the highest power levels (512 511 510 ) kw with the V3 battery do so using LM (launch mode) ? I have logged 505kw at 100 SOC without LM and I don't think I had max battery ready, though that might not matter since I had just supercharged from under 100 rated miles to a full charge 272 RM which most likely heated the battery enough to equal max battery ready. So I am curious if just pulling the extra amp difference between 510 ish kw using LM and the 505 kw
Not using LM is when the damage occurs?

 

[wk057]

Wonder how resetting this as a paid service would go over with Tesla...

 

[Garlan Garner]

Still upset about this.... Hmm so they added it to the manual now, great... By the time I picked up my car in June I had read that thing front to back, there was no warning about launch mode, also went though the in car manual a few times and there was no warning... Just so disappointing to discover this, though I'm happy we can prevent it for other owners and that there is now a listed warning, Its something that should have been listed and provided with my NEW car... Unfortunately I found this out the hard way and have no chance to prevent the damage so basically I'm punished for discovering something that tesla should have told us about.... Thats quite a sour taste in my mouth Tesla did Too Little Too Late for me!!! I took delivery 6 months ago and NOW they add this to the manual?!

Oh ya and UNLIKE THE EMAIL I RECEIVED I don't see any mention of the P100DL being excluded from this limitation in the manual so BUYER BEWARE!!!

So...would have not purchased your car if you knew this?

I hope Tesla doesn't take anything else away from your car that might cause it to catch on fire - and not tell you.

 

[Walta]

So...would have not purchased your car if you knew this?

I hope Tesla doesn't take anything else away from your car that might cause it to catch on fire - and not tell you.

The better reasoning would be why would tesla provide and support using launch mode when it could damage the drive train? It appears to me from their actions they were trying their best to deliver on the 10.9 promise and did not properly test and evaluate the negative impact when combining launch mode with the higher amps provided by the V2 and V3 batteries. Nothing to do with causing a fire.