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Tesla Admits To Sometimes Limiting Battery Output / HP If Launch Mode Is Used Too Often
DEC 24 2016 BY ERIC LOVEDAY 21
Launch Mode Details Via Tesla
It seems as though Tesla keeps a relatively close eye on Launch Mode usage in certain versions of the Model S (P90D) and probably on other non P100DL versions of the S and X too (see Tesla’s statement below).
Tesla Model S P100D Ludicrous & Tesla Model S P90D Ludicrous (via Tesla Racing Channel)
Launch Mode is only available on dual-motor Teslas and it’s there to extract the maximum in off-the-line acceleration, but it appears as though over time, Launch Mode can lose its oomph, so to say.
One Tesla Model S P90D owner experienced this apparent loss in Launch Mode power, so he reached out to Tesla and then posted this on Tesla Motors Club Forum (via Electrek):
“Unfortunately I’m here to say this is true. My car was limited just after the 8.0 update and at first I was convinced it was related to that. I did lots of testing and emailed Tesla my findings. Before this limitation my car would pull around 1600 amps from the battery and 512 KW of power when fully charged, now the car will only pull around 1500 amps and 480 KW of power, a loss of about 40 HP on a 4 month old car.”
A Tesla representative responded to his inquiry with this statement:
“Thank you for your time. To recap our conversation, using launch mode places an increased stress on the entire powertrain accelerating aging and fatigue of various components. The computer systems automatically track launch mode usage and continually estimate fatigue damage. Depending on how launch mode is used, the computer may eventually limit the available power during launch mode to protect the powertrain. Note that this is a common strategy also employed in other high performance cars. As discussed, upgrading to the P100D ludicrous will remove this limit and will not be limited in the future as the P100D does not have this limit for launch mode.”
Launch Mode shouldn’t be overused. It’s there for that occasional situation that warrants its usage. On-track racing typically voids warranty. It seems Tesla is attempting to protect the vehicle, rather than allowing over usage that could lead to component failure.
Electrek asked Tesla for comment on this and received this response:
“Like other automakers, our performance vehicles continually monitor the condition of various components and may employ limiting strategies to reduce fatigue on the powertrain.”
Seems acceptable to us. The only issue of course is that Tesla has not communicated this limiting of output could be implemented at the point of sale, which opens the company up to further scrutiny, or perhaps another round of legal action on performance, as found earlier with how Tesla was reporting the motor output on some of its vehicles as compared to actual real world performance.
Source: Tesla Motors Club Forum via Electrek
Categories: Tesla
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21 Comments on "Tesla Admits To Sometimes Limiting Battery Output / HP If Launch Mode Is Used Too Often"
Whether Tesla should, or should not, limit Launch capability this way, is a matter for debate. Obviously there are good arguments to be made on both sides.
What should not be a matter for debate is that Tesla absolutely should not have taken the step of limiting power available from Launch mode without informing its customers. Not doing so makes it look like Tesla was deliberately hiding something.
And this isn’t the first time Tesla has done such a thing. You’d think that learning would have taken place, but it hasn’t. Why would any company try to hide something that people are eventually gonna figure out? Best to state it openly, and eliminate the accusations that will only feed into the anti-Tesla bashers’ rhetoric.
Just like politicians trying to hide nefarious activities by their underlings: What really gets people mad isn’t so much the initial offense, it’s the coverup.
“Seems acceptable to us”
Why would it be acceptable to have your car limited, through on-board computer monitoring or updates (who knows?), and then have the company that sold it to you try and say they won’t do it…if only you’d “upgrade to the ($150k) P100D lucicrous”?
Tesla should name companies, or at least methods, where other OEMs are muting performance not because of wear, but in prevention of wear. “They do it, so can we” doesn’t make all warm, fuzzy and accepting.
I can name two right off the top of my head.
BMW 335’s with twin turbos. They got a power cut:
http://www.bimmerforums.com/forum/showthread.php?1574762-BMW-is-secretly-de-tuning-the-n54
Closer to our EV home, the Honda Civic PHEV got a flash to reduce the amount of battery used, to avoid killing the battery prematurely. This reduced both performance and MPG.
It would probably be easy to find more examples.
Every time you go in and they flash your car, they can fiddle with the computer in order to make your car last longer and prevent problems.
Well frankly I don’t think we should accept this sort of bulls*** from either Tesla or BMW!
Oops, forgot link for Honda:
http://www.bimmerforums.com/forum/showthread.php?1574762-BMW-is-secretly-de-tuning-the-n54
double oops. Wrong link. This is the right one.
http://www.diyelectriccar.com/forums/showthread.php/honda-civic-insight-ima-and-mods-22795.html
The gear strain stress is excessive in those situations. The Motor is loaded to max and then we have lots of current and heat to deal with as well.
The drive unit is physically not build for an unlimited number of cycles of this kind of loading.
Therefore Tesla limits the amount of cycles you can put on the drive train to be in line with the design limit.
It makes sense to me.
Frankly, it doesn’t make sense to me. If it puts that much strain on the drivetrain, then the car shouldn’t be engineered to do that at all. Not even once.
Or, to argue from the other direction, this indicates the drivetrain needs to be beefed up… and the frequency of failure, the “milling noise” problem which was frequently reported early on in Model S production and still pops up sometimes, seems to be another indication that Tesla needs to beef up the drivetrain, or at least certain parts of it such as the (reduction gear) gearbox.
“If it puts that much strain on the drivetrain, then the car shouldn’t be engineered to do that at all. Not even once.”
No offense but I can tell you have zero engineering background.
The drive system is designed for a certain number of cycles. It is not un like a battery that also has a “cycle life” as the engineering term goes.
So your statement makes no sense.
Technically, you are correct. However, a well engineered product should last the lifetime of its expected usage (ie, warranty period). If that means exercising to the fullest extent of its capability, then it should be so. That’s how we run things with electrical engineering devices; if it breaks on peak usage, that’s deemed poorly engineered product.
But when it comes to cars, they are often designed to break at full usage (ie, clutch slip too often). It’s not that cars are poorly engineered, but EE do far better. 😉
..especially if the at is marketed as “insane, or “ludicrous”. It should be engineered for long term performance. We don’t know the counter, and I am cynical it only trips after, say, a hundred launches. We don’t how many. We know if we upgrade we (supposedly) escape what may be a slippery slope of forced obsolescence.
Even Nissan limited the torque on the Leaf, although that wasn’t hidden, it was at a model year change.
Nissan and most other do limit launch torque from the factory at 0 miles.
Tesla’s system is unique. It allows you to feel what the car is capable of, then cuts the power.
This a bad precedent for all high performance car makers. Sure, void our driveline warranty. Sure gimp the car at launch.
Don’t sell a car that hauls ass the first day, then make it go slow after you’ve made sure the check cleared.
Tesla should have informed customer about the limitations up front.
Bull.
Some mfr’s will void driveline damage when dragracing. Others will limit torque from the factory.
I would LOVE to see an example of a car that detunes itself due to high performance use.
By the way…
The World’s Most Evil Automaker will not void your driveline warranty for beating the s**** out of the car on the track, as long as you have not modified it.
Been there, done that. It’s not just a claim, it’s not a rumor, they really fix the car for free for pushing the car to 100% on a closed course. Unlimited except by normal warranty duration.
All EVs do that to limit damage to powertrain and battery.
Volt, LEAF, Prius Prime, BMW i3, Ford Energi series all do that as well.
“This is for your protection during the transition period.” – VIKI-controlled robot army.