If you fast charge, Tesla will permanently throttle charging

[mhan00]

Interesting / long thread with the usual, expected, viewpoints... hoping Tesla/ @JonMc helps us all understand the counter increment criteria and thresholds on which limits, to help stop the masterdebaters (see what I did there? ;-))

On a separate question: Given that there are numerous counters that affect charging rates permanently based upon use history, has anyone done the determination of potential impact if/when able to charge at Elon's promised >300kW updated SpCs?

Pointless exercise, really, since no current car will ever reach those levels. Beyond just the batteries not able to receive that level of charge since they would be damaged, the other components wouldn't be able to withstand it either. Either wk057 or one of the other engineers/hackers who break down the packs noted that the wires and other components of the car would have to be upgraded to safely transfer/absorb the heat generated by that much electricity. Any cars that could take advantage of that would have different battery chemistries and any calculations done here would have no bearing on them.

 

[Zythryn]

Would you be willing to report on your Model X 90D roughly:

1) Total miles on the X
2) Total percentage Supercharged/CHAdeMO (vs. other) on the X
3) Peak Supercharging kW currently on the X

I understand if you don't, just asking since 90 kWh seems to be the interesting data point and you may have a higher mileage (above 30,000 miles) one. Thank you for considering.

The X would give very little data.
It is less than a year old, has under 10,000 miles and is rarely SC'd.

Our Sig S had much more history, but of course, it didn't have the newer batteries.

 

[MikeBur]

Pointless exercise, really, since no current car will ever reach those levels. Beyond just the batteries not able to receive that level of charge since they would be damaged, the other components wouldn't be able to withstand it either. Either wk057 or one of the other engineers/hackers who break down the packs noted that the wires and other components of the car would have to be upgraded to safely transfer/absorb the heat generated by that much electricity. Any cars that could take advantage of that would have different battery chemistries and any calculations done here would have no bearing on them.

So, besides Tesla Semi, why would Elon goad folk with expectation of 350kW stations? Obviously this wasn't about charging current batteries at 350kW, as that would be a crazy C rate, even if the connectivity infrastructure could take it. Rather what's the max a current battery could take today - is it 150kW, 200, etc? And presuming such, how would this impact battery longevity today, as well as known future batteries

Definite pontification, though based on articles published regarding EV *car* charging stations: The first ‘High-Power fast-charging station’ (150-350 kW) is installed by EVgo and ABB right in Tesla’s backyard

 

[Canuck]

1% is based upon the fact that this didn't apply at all to older vehicles with the different battery chemistry. Given the imminent arrival of Model 3's, today's 1% could very well be tomorrow's 25%.

That logic seems flawed to me.

This seems more reasonable of a conclusion to draw: Tesla adds silicone and Elon says they are taking "baby steps" in doing so; they learn the silicone causes faster degradation when fast charging, and that the old chemistry works better. After they learn this, all vehicles produced use the old chemistry, as will the Model 3. Hence, this affects less than 1%.

So regardless of whether or not it was a recent lesson learned by Tesla, they failed to disclose it when they did learn it.

Hmmm.... is it a general press release or just reaching out to those who may be affected that you expected? It seems too much of a stretch to me to expect this from Tesla, or any large corporation, in a scenario when it makes absolutely no difference to the vast majority of owners. Even when it does make a difference to most owners, I expect companies to try to save their own butts over their customers' butts. Then again, I have very low expectations of large corporations. I expect them to screw us whenever they can, and most meet my expectations. Expecting full and prompt disclosure from corporations makes me laugh, since my mind turns to shredders and not press releases. I guess that way I set myself up for less disappointment but in my view, this is the reality of the world we live in. VW just happened to get caught in my view, whereas many others have got away with, and were even rewarded by similar conduct, In fact, some even get huge bonuses for grossly negligent, and arguably criminal, conduct -- just look at the financial institutions bailout.

My position doesn't make the conduct right, but it does lead me to hammer Tesla to tell us the trigger, rather than to harp on when it should have been disclosed.

 

[TexasEV]

i love how newbies like you get a Tesla and within a year you think you're Elon Jr and talk down to everyone else.

so to answer your basic-boy questions:

Not sure where you get the idea I'm a "newbie". I too have had my Model S since 2013. It's pre-parking sensors and auto folding mirrors.

Since you have had a Model S for four years, you would know that your post about how the first time you charged your P100D you were down to 30 kW, without providing any other relevant information, could be interpreted as not understanding supercharging. Since you do understand supercharging, posting that contributed even less to the discussion.

 

[MikeBur]

Correct. I don't believe it takes into account the actual charge rate. I too have been stuck on 10 mins remaining for over 20 mins.

This might be due to some of the balancing toward end of charge cycle as well, i.e. Not just non-linear taper (that's relatively easy to factor in). I don't know how to just link to a post, though ~year ago I generated some charging graphs showing this as an animation. Clicking on the up arrow on my quoted thread below will take you to that page I hope, otherwise it's post 446 on this URL: Chassis CAN Logging To ASCII Text Plus Graphing

(Edit) Direct link: Chassis CAN Logging To ASCII Text Plus Graphing
The animation goes fast, sorry, though there's a few frames showing balancing.

Few more graphs on the charging side of things:


First, supercharging session. From 58 to 90% SoC - normally wouldn't charge this much on SC though a) it was completely empty and b) I was logging

Initial ramp is as expected, with significant falloff/lower power due to reasonably high SoC as start.
View attachment 114003

Next comparison between this Supercharging session and CHAdeMO. CHAdeMO is longer and although started at lower SoC, still shows benefit of SpC over CHAdeMO. (Dotted is CHAdeMO, translucent lines is SpC)
View attachment 114004

- - - Updated - - -

Few animated gifs for charging. I thought these were pretty boring, though some wanted them. Let me know if you want these to be shared in future. Kudos, and paypal donation, to ezgif.com - if you use remember to use optimize for transparency (reduces from many MB to much few KB) and speed up animation (about 6ms between frames seems good).

Animations and source data on Google drive. btw - If you select 1 (instead of 0) for GenImages in the Battery*.xlsm files and click "animate" on the excel tab then per frame gifs will be output into c:\temp\ directory

Supercharging:

Individual Cell Voltage whilst charging
View attachment 114015


Module Temp
View attachment 114016


- - - Updated - - -

CHAdeMO charging session animated Gifs:


Cell Voltage
View attachment 114017


Module Temperature
View attachment 114018


Again, if these are not useful let me know. It's a lot easier to *not* generate these ;-)

 

[stopcrazypp]

To be honest I don't see this applying here. Almost all Chaedmo stations I encounter are capped at 50 kw. That is even less than 60 kw standard regen. If Tesla is counsidering this in the algorithm, then they will also need to have a regen counter since, by extension, this would also be impacting pack health. Seems unreasonable IMO.

Regen is also going to be a short amount of time. You are also moving when on regen, so the cooling system would be a lot more effective and there would also be airflow under the battery.

As I touched in my post here, the temperature, time, charge rate all matters.
If you fast charge, Tesla will permanently throttle charging

It can't be purely due to resistance increase, since transitioning from 115 to 90 is (to my understanding) abrupt.

Ok, got it. So then there is literally some DC charge counter that, when it exceeds a threshold, activates a trigger.

@Naonak says it's gradual here:
If you fast charge, Tesla will permanently throttle charging

Hard to keep track of everything.

 

[mhan00]

I was just told by JAX ctr that a super charger rate of 115kw was OK but it is DC power and stressful on batteries, my fans come on and sound like it is going to explode. She said it was normal. Then she said. If don't come back and UNPLUG my car when it's full, I will charged an Idling fee?? Whiskey tango foxtrot, Over?
And double charger only works I have 100 amp circuit in hose? Good luck on that upgrade to house.

The fans are there to cool the battery while charging to make sure the heat doesn't destroy your battery. It's supposed to do that.

Don't go back just to unplug your car. MOVE IT. SCs are for charging, not parking. When your charge is complete, common courtesy dictates that you should clear the space for someone else who might need a charge. The idle fee is there to encourage people to do so.

 

[stopcrazypp]

That logic seems flawed to me.

This seems more reasonable of a conclusion to draw: Tesla adds silicone and Elon says they are taking "baby steps" in doing so; they learn the silicone causes faster degradation when fast charging, and that the old chemistry works better. After they learn this, all vehicles produced use the old chemistry, as will the Model 3. Hence, this affects less than 1%.

Just a small correction. It's silicon, not silicone.

 

[Ugliest1]

Hey have you noticed that when you plug in at a SpC, it may say 50 minutes remaining, but when you leave for 30 minutes and come back, it doesn't say 20 minutes, it says 30 minutes remaining? I've noticed that the time is not accurate, and it ALWAYS takes longer than the estimated time. Could the time be based on some "ideal" rate, and not taking into account the actual charge rate?

I've noticed that the time is rather approximate, and is even more approximate once you get into the 90-100% range charging. However, I go more by my travel plan and how much buffer I want, and those two together are even more flexible than Tesla's timing, given what I think the weather might be doing (raining, windy = more buffer). I should mention that we only supercharge on long trips, I don't have a regular long commute where perhaps time is in shorter supply.

And because I want a bit of a buffer, the "you now have enough charge to continue on your trip" message is NEVER true. That doesn't bother me; the few times we are waiting in the car we just keep reading or otherwise entertaining ourselves. Most of the time however we haven't finished our walk, or coffee, or whatever before the car is well ready with plenty of buffer.

 

[MikeBur]

I've noticed that the time is rather approximate, and is even more approximate once you get into the 90-100% range charging. However, I go more by my travel plan and how much buffer I want, and those two together are even more flexible than Tesla's timing, given what I think the weather might be doing (raining, windy = more buffer). I should mention that we only supercharge on long trips, I don't have a regular long commute where perhaps time is in shorter supply.

And because I want a bit of a buffer, the "you now have enough charge to continue on your trip" message is NEVER true. That doesn't bother me; the few times we are waiting in the car we just keep reading or otherwise entertaining ourselves. Most of the time however we haven't finished our walk, or coffee, or whatever before the car is well ready with plenty of buffer.

See my post above. 90-100% range you're definitely going to charge slow due to taper. If you're charging to 100% you'll be spending a lot of time balancing battery.

 

[mhan00]

So, besides Tesla Semi, why would Elon goad folk with expectation of 350kW stations? Obviously this wasn't about charging current batteries at 350kW, as that would be a crazy C rate, even if the connectivity infrastructure could take it. Rather what's the max a current battery could take today - is it 150kW, 200, etc? And presuming such, how would this impact battery longevity today, as well as known future batteries

Definite pontification, though based on articles published regarding EV *car* charging stations: The first ‘High-Power fast-charging station’ (150-350 kW) is installed by EVgo and ABB right in Tesla’s backyard

Musk, you might have noticed, is very optimistic. He also appears to be a guy who goes into a project looking to shoot for the stars to make sure that expectations don't limit him, so even if he misses on the stars he ends up on top of the mountain.

Beyond that, though, the increased power rate might only be there to support more stalls. With a 350 kWh SC, for example, they could pair three or four stalls to one and all the stalls could get close to max charge even with multiple cars charging in paired stalls. So there would be more benefits than just shoving more electricity into a single car even faster. And maybe there will be a battery break through in the near future so that cars can take advantage of that rate in the near future.

 

[stopcrazypp]

1% is based upon the fact that this didn't apply at all to older vehicles with the different battery chemistry. Given the imminent arrival of Model 3's, today's 1% could very well be tomorrow's 25%.

But we don't know if Model 3 will use the same chemistry or even if the newest 75 and 100s out of the factory is using the same chemistry.

If this is really an issue related to a specific chemistry, I would expect Tesla to move away from it. The statements quoted for Elon suggests they are constantly making adjustments anyways.

 

[NerdUno]

Samsung continually made battery adjustments, too. And that went well.

 

[Electroman]

They didn't inform those people that may be affected...

Instead, they should have said "Oh, you do have a problem, we will replace your battery with a non-affected battery if you want."

The point is your car is not affected. it works within the parameters, because Tesla never guaranteed a specific charge rate at an SC. So there is really nothing for Tesla to disclose or give you a new battery (oh really, a new battery?! )

This is in completely contrast to the performance issues Norway folks raised. Tesla did document what performance and HP they would get, and many bought with those numbers in mind. In this case all you were told is, some x% in 30 minutes assuming all the right parameters exists, which it rarely does even for new cars. You were never told or guaranteed, 110kW from 0 to 30 miles and then 90kw from 30 to 150 miles.. etc

FWIW my 85 even on a cool day, only stays above 100kW till 0 to 25 miles and then drops to 85kw pretty quickly and by the time the range is 100 miles it is hovering around 70 to 80 kW. Of course I have only SC'd 8 times so far, and no idea how many times the previous owner charged. Not that I care.

 

[anticitizen13.7]

Samsung continually made battery adjustments, too. And that went well.

The problem with the Samsung Galaxy Note 7's batteries was due to the geometry of the Lithium Polymer pouch being slightly too big for the phone's enclosure. This is a different issue than changes to the chemistry.

 

[msnow]

Let me try. You are probably correct. They did not guarantee. Their sales contract is probably pretty strong. What they did do is a) post charge rates/times on website, and b) say in numerous forums that supercharging would not harm battery. The people upset about this want to know details and feel they were misled. I suspect they were not intentionally misled. Regardless, it has upset them and tested their trust in the company. My personal views aside, I think that is the complaint.

This isn't the first time or first issue where we have heard non-transparent, misleading, vague responses from Tesla. The 694 HP issue, 2015 90D's rapid range loss, Josh Brown NHTSA incident, AP1 and 2 persistant problems, the Model X rollout, and "countergate" are all examples of this. They really need to get their act together before the M3 comes out. Who else but us would put up with this stuff?
I think people would feel better with honest, straightforward communication than what we have seen lately.

 

[SMAlset]

I was just told by JAX ctr that a super charger rate of 115kw was OK but it is DC power and stressful on batteries, my fans come on and sound like it is going to explode. She said it was normal. Then she said. If don't come back and UNPLUG my car when it's full, I will charged an Idling fee?? Whiskey tango foxtrot, Over?
And double charger only works I have 100 amp circuit in hose? Good luck on that upgrade to house.

When your range is low and you are supercharging, yep the fans come on and it does sound like your about to take off. Normal. The fans do reduce in speed and noise as the charge rate changes.

Idle fees due come into play if you leave your car in a stall after charging after a certain period of time. Don't remember the specifics as we don't have need to supercharge much. Maybe someone can point you to the info. If you leave the car you need to monitor your app.

As for the dual high amp wall connector -- Tesla says this "For vehicles with a High Amperage charger upgrade (72A) install Wall Connector with a 90 amp circuit breaker. For power sharing with more than one Tesla, install with as much power as possible, up to 100 amps." Be safe and get the appropriate electrical work done. Most of us have had to upgrade service be it for a NEMA 14-50 or the wall connector--part of the cost of going EV.

 

[Benjamin Brooks]

Surely the BMS isn't using a DCFC session counter to limit the max battery charge rate?
All my slow ~30-60kW SuperCharging in CA and my CHAdeMo charging shouldn't go against the pack's peak C.
Maybe we need to get wk057 or Ingineer to test this on a torn down BMU module...

 

[jchag]

I just want to add, it's not the throttling that irks me. It's the fact that Tesla hid the fact that DC Fast Charging causes degradation and that they will permanently throttle your charging rate if you do it.

Couple that with the low ceiling of < 300 DC Fast charges, and you are basically selling a car that WILL get throttled at some point in its life. If that information had been communicated from the start, that's an entirely different discussion.



Yes, I'm glad you agree with me, then. Since it is on their website saying you can get this under ideal conditions, that's a form of a guarantee. Since the car is throttled, it can NEVER reach those conditions, making those conditions impossible to obtain, ergo their guarantee is impossible to achieve.

It would be like selling a car saying "Gets up to 150 mpg" ... but only if you start at the top of a mountain and coast the whole way down... and then have the car towed the additional 100 miles. Yes, it will get 150 mpg under ideal conditions, but no person in their right mind would say that car can get 150 mpg. This is the same thing. No person in their right mind would say a 90 kW throttled car will get 170 miles in 30 minutes. There's simply no possible scenario where those ideal conditions can be met. And in fact, it's even more absurd, since I could theoretically replicate the 150mpg conditions. I have absolutely no way to replicate the conditions of 170 miles in 30 minutes, since I have no ability to turn off throttling (regardless of the consequences). Even replacing the pack might not be sufficient, as the BMS would still potentially throttle the charging.

They are throttling you for mainly using a Chademo which itself is a throttled Supercharger, That shouldn't count