If you fast charge, Tesla will permanently throttle charging

[bhzmark]

It's fascinating psychology, isn't it? People so passionate over their expensive purchase, that they engage in a cult-like brand defense. Cognitive Dissonance 101.

I see a different psychology -- one that Louis CK described:

Posts that have no purpose other than to insult people who disagree with them just bring this thread into the gutter.

I see those posts that just contain insults rather than any useful information or analysis as indicating that the member is unlikely to have a signal/noise ratio that is worth reading and it serves as a trigger for me to add them to my ignore list. The forum is so much more pleasant with an aggressive ignore list. I recommend readers to use it liberally and resist the temptation to click on "Show Ignored Content."

Meanwhile, do we still have no reports of anyone else confirming a throttled car? With all those cars that use superchargers so much, none of them have reported a throttled car?

 

[Ulmo]

Despite what people think, not even Elon can violate the Laws of Physics... well, laws of electrochemistry in this case.
This is why my home charging is set at a more "gentle" 30A each night. No point slamming electrons in there too fast when there's no need.

One theory is that fast charging is better for the batteries than trickle charging. It's hard to know what's best without seeing a huge amount of evidence.

My guess: The energy from Superchargers is paid by Tesla and it adds up fast when someone is supercharging (or what appears to be SC) excessively. So excessive users get throttled back to discourage this practice.

Then why should I be penalized for paying $0.15/kWh to $0.20/kWh at an EVGO that has nothing to do with Tesla? In their Record of Work originally posted above, they said the reason for it was to protect the battery?

So every weekend of every year your hypothetical Tesla owner drives 400 - 600 miles each way.

Come ON. I'm sure you can come up with something a bit more realistic

That's my pattern and the second reason why I bought a Tesla rather than a practically free Leaf (the first being safety). But, I recognize I'm in a unique high-mileage group. However, this throttling seems either excessive, wrongly implemented, or wrongly communicated, at least. My mileage is supposed to degrade slower per mile than that of other high mileage cars because it is across less time; it shouldn't degrade faster per mile than other high mileage cars.

Here is what I think: Tesla designed the car around use of 15k miles a year and 10% DCFC. That works out to 15 DCFC uses a year. In order to accommodate a couple or three standard deviations from normal they considered typical use of up to ~ FIFTY DCFC uses a year. Past that and the owner is an outlier who will have to decide if a Tesla is the right tool for the job.

If that's even close to true, they'd have to reveal it.

Moderator: Can we change the title ?
"If you Fast Charge Like Me, Tesla will Permanently Throttle Charging."

You must be assuming almost no Tesla will make it to 1,000,000 miles before needing something so expensive to replace it's better to junk it.

Really? I'm pretty sure he has given most of that information in the thread:

• 2015 P90DL
• ~1 year old
• ~30k miles
• ~250 CHAdeMO charges
• ~55 Supercharges
• Next to zero AC charges

Add this (he answered my question about charging to 100%): "No, I usually charge to less than 90%. Sometimes I will charge to about 93% and drive immediately. I virtually never charge to 100% on CHADeMo... I would go so far as to say I never have, but it may have happened once by accident."

Could it be that this restriction applies if you use Chademo, instead of SuC?

I have the same question.

I've read through this entire thread and haven't seen any good conspiracy theories yet. So let me be the first. Could this be Tesla's way of punishing those customers they feel are abusing the SuC system? If they see someone with lifetime free access using the Superchargers almost exclusively they will throttle their charging speeds. This would be equivalent to the cell phone carriers who throttle network speeds of their unlimited plan customers when they think they are using too much bandwidth. Maybe Supercharging is no more detrimental to the battery than any other method but Tesla feels like they need to punish those they think are abusing their charging network.

Conspiracy theories? How about: Chademo is bad since it puts Teslas next to those lesser EV's, giving it a bad reputation.

In both cases, it's hard to understand the outcome working, though; in yours, the SuC would have more users, filling the SuC more, and the users would be spending more time at coffee shops, shopping, etc., to make up for it. It will make their days longer and they'll get to fewer SuC's, but then they'll be out on the road more since they'll have to get more hotels, and end up SuC'ing more unless they can't afford that lifestyle. In case of Chademo conspiracy, it wouldn't reduce their Chademo use, it would increase it, since they'd get relatively more effect from Chademo than SuC (because less effect (slower) from SuC).

 

[JRP3]

We don't know that there are counters or throttlers. This is speculation only.

In fact it may be simply that the BMS constantly calculates internal cell resistance and when it reaches a certain level it reduces charge speed to keep the cells within certain parameters. It may be that certain packs are more susceptible to this and that higher power charging exacerbates it. Since it seems that frequent supercharging does not negatively impact total pack capacity I think it relates more to ion flow during charging. My guess is that eventually over time all packs will eventually show increased resistance no matter what type of charging was used and max charge rate, and discharge rate, will decrease, but for most people it wont be an issue. So it's not necessarily a new or separate "throttler" but just the way the BMS manages the pack to preserve it's overall health. Batteries wear out and internal resistance increases as they do, all that can be done is to mitigate that as much as possible. Tesla should be clear that this is an inherent fact and inform people if certain behaviors are known to accelerate it.

Speculation: High power charging seems to limit time available for unwanted side reactions to occur in cells and actually preserve capacity, (proposed by Prof. Dahn's work), moderately high power charging, i.e. Chademo, may be powerful enough to create unwanted side reactions but not fast enough to limit them. Again, speculation.

 

[OBX John]

I
I see those posts that just contain insults rather than any useful information or analysis as indicating that the member is unlikely to have a signal/noise ratio that is worth reading and it serves as a trigger for me to add them to my ignore list. The forum is so much more pleasant with an aggressive ignore list. I recommend readers to use it liberally and resist the temptation to click on "Show Ignored Content."

I completely agree.

So many important threads and issues like this software limited DC charging attract the usual complainers and devolve into a bunch of whining that obfuscates the informative and balanced posts. I've just started to aggressively "ignore", and it does make this a much more pleasant and informative forum.

Back on topic, I had terrible supercharging rates at the Glenn Allen, VA location on my way back from the mountains. Topped out at 213 miles/hr even though my battery was only 1/3 full and kept getting lower with each stall switch all the way down to 140 miles/hr. I wish the car would give me some clue why, rather than making me switch stalls in vain.

 

[Merrill]

I guess it is a good thing both my wife and I are retired and never in a hurry to get anywhere. We have nothing but time and enjoy taking a ride somewhere for lunch, even when we take trips another 10 or 15 minutes is no big deal. Hopefully those that are in a hurry and have to get somewhere in the least amount of time will someday be able to stop and smell the roses.

 

[AnxietyRanger]

Meanwhile, do we still have no reports of anyone else confirming a throttled car? With all those cars that use superchargers so much, none of them have reported a throttled car?

With your self-admitted aggressive ignore list you don't see all the reports I guess. In addition to @Naonak, @Bjorn just reported he is affected. And of course we also have two different forum members reporting Tesla saying this as well. See msg #385.

 

[Adrian]

@AnxietyRanger So far the common denominator seems to be the 90 kWh packs, no? Bjørn was very early suspicious of something like this happening.

 

[Drumheller]

@AnxietyRanger So far the common denominator seems to be the 90 kWh packs, no? Bjørn was very early suspicious of something like this happening.

I can add that I have an older 85 kWh pack, 70,700 miles, and probably over 200 supercharger visits in the past year as I traveled around the USA. Still saw 115 kW peak on supercharging last weekend. It does seem to take a bit longer to charge than it did a year ago and I attributed that to either battery aging or the supercharger being a bit slower. It wasn't much, perhaps up to 5 extra minutes on what was expected to be a 30 minute charge.

 

[Adrian]

With the introduction of 8.0 there was an immediate massive drop in SC speed for the 90 kWh which @Bjorn documented from several users on the norwegian FB group forum. From 110+ kW on 7.* with a drop:

to under 90 or so kW max for a long duration.

In later updates the speed has climbed back up a bit, his car now maxing at 95-96 kW. He made a video of this:

 

[AnxietyRanger]

8.0 is of course the firmware that also introduced the infamous Performance/Ludicrous counters...

 

[beingpaulp]

I will add my unique situation:

2015 85D - one of the first to be delivered
I got the single charger and installed chademo at home. My thinking is it would be more practical for my uses.

I drive a lot, it's normal for me to charge 3 times in a single day. I sometimes get home and have to leave 1-2 hours later. My neighbor with a dual-charger tesla has a similar work/commute and sometimes comes over to "fast charge".

I'm like the OP, over 70k miles and I've maybe charged 300 miles with level 2

I have a photo of my first supercharger session which was 115kw, for a long time I have never had a supercharger go over 87kw

On my first visit to a service center, the advisor said to not use the supercharger because of degradation. I asked him if the chademo was the same, he wasn't sure, but later called me back and told me it was.

This just confirms what I've long suspected. Doesn't surprise me, it would have been nice to know before I spent $100k, but I've adapted to it.

 

[Adrian]

I will add my unique situation:

2015 85D - one of the first to be delivered
I got the single charger and installed chademo at home. My thinking is it would be more practical for my uses.

Two questions:
1) Aren't those the 90 kWh upgradeable packs? This would contribute to the above findings.
2) CHAdeMO at home? I'd love to have a look at that setup!

 

[Ulmo]

In fact it may be simply that the BMS constantly calculates internal cell resistance and when it reaches a certain level it reduces charge speed to keep the cells within certain parameters. It may be that certain packs are more susceptible to this and that higher power charging exacerbates it. Since it seems that frequent supercharging does not negatively impact total pack capacity I think it relates more to ion flow during charging. My guess is that eventually over time all packs will eventually show increased resistance no matter what type of charging was used and max charge rate, and discharge rate, will decrease, but for most people it wont be an issue. So it's not necessarily a new or separate "throttler" but just the way the BMS manages the pack to preserve it's overall health. Batteries wear out and internal resistance increases as they do, all that can be done is to mitigate that as much as possible. Tesla should be clear that this is an inherent fact and inform people if certain behaviors are known to accelerate it.

Speculation: High power charging seems to limit time available for unwanted side reactions to occur in cells and actually preserve capacity, (proposed by Prof. Dahn's work), moderately high power charging, i.e. Chademo, may be powerful enough to create unwanted side reactions but not fast enough to limit them. Again, speculation.

All these theories seem quite possible, but we don't know since Tesla won't tell us. What I want to know is this:

• I'm planning my day.
• Do I use:
  • the Chademo at the top of Hwy 17 (after just having driven uphill (and does traffic matter?))
  • the Chademo in Campbell before hitting Hwy 17 uphill
    
  • the SuperCharger in Gilroy
  • Arrive home with 0% SOC and let it charge to 10% at $0.55/kWh @ 11kW peak evening use rates and with VisibleTesla have it shut off at 10% SOC and then it automatically restarts itself at 11:05PM that I have it normally set to?
  • Find a Level 2 charger sometime during the day and make a 2 hour lunch out of it
    • The only available Level 2 charger I know is outrageously expensive as far as I know, and next to a very nicely priced 42kW Chademo that I like to use since it is in the middle of a bunch of businesses I use, and a few of those businesses are really nice. Is this 42kW Chademo OK to use? ?! I like using it on days I go to those businesses because it exactly fills my need. Do I attempt to use that Chademo more rather than less in the future, by making even more use of those businesses and tailoring my life around them? The answer about charging makes a big difference.
    • Other Level 2 chargers in that area are all pretty much in 100% use, and I can't get a slot. Most of them are hidden behind extremely high price parking and charge at an anemic 6kW, half my home speed, meaning spending a huge amount of time in expensive dangerous neighborhoods with bad quality businesses that are soul-sucking.
• And, while doing any of the above, do I try to do it in a certain way, such as SuperCharger, Chademo, or Level 2, at low or high state of charge, or only for a specified amount of time, or pick one that is 20kW rather than 42kW, or in the sun or in the shade, or right after driving or right before driving, or something?

That's all I want to know. Tesla doesn't want to answer us. Until they do, I don't know that I have any way to figure out the best path.

---

Edit: I'm going to use tonight as an example. Since I wrote this post, I found out I'm going to be going to Santa Clara this evening. I consider the likelyhood that I will then go on to do more things after that to be nonzero, meaning I should add some charge so that I can do those things if need be and then get home. There happens to be, exactly where I think I want to park, the following options, according to PlugShare:

• Overly expensive ChargePoint Level 2's (the cost is set by the landlord, not the network)
• an EVGO Chademo (I have the monthly plan and know that I like the cost structure --- about same as home charging)

So, which do I use? The overly expensive ChargePoints, because they don't degrade my battery faster, or the Chademo that is lower cost, because it won't degrade my battery any more than the Level 2 chargers?

Furthermore, should I arrive early, sit in my car, read a book, and Chademo up about 25% SOC, then unplug, or should I walk away and let it go to 100% (*60/75)? Of course, this is before I even know the parking costs, the time limits on charging, etc., so it all has to be taken into account. But, if I have an opportunity to walk over to my car and re-park it while there, then this might all be very reasonable to consider.

All of this could be answered by Tesla, but they won't tell us.

 

[bonnie]

So, when posts like yours appear, they might be perceived by some towards cheerleader-ish spectrum.

Look, if you disagree ... fine. But why such an effort to make it personal?

Go ahead and disagree. Have at it. But you seem to take great offense with the people who express opinions that don't align with your views. When I disagree with you, it's not personal. I have zero need to attack you personally. But I will express a differing opinion if I have one, and will try to do so respectfully.

 

[AnxietyRanger]

Thanks for the note, @beingpaulp. It seems reports on this are now starting to surface from many people...

I brought up the CHAdeMO home charger point earlier. People do have them...

 

[Canuck]

I don't think anyone beyond @Canuck and @S3XY believe in that theory, anyway. Seems like on outlier of a theory.

To me, it's just plain silly to believe that Tesla is trying to protect the battery when all the stats prove that constant supercharger or chademo charging will never degrade it to the point that it will lose over 30% of capacity during the warranty period. In fact, the stats show it is no worse, and in some cases better, than AC charging. (I know all charging is DC charging but I refer to AC when the onboard charger does the conversion to DC.)

Plus, my theory accounts for why it is happening to the OP and not all others who have a similar amount of fast charging -- because the OP is not using AC charging as well. What other theory has an explanation for this happening to the OP and not others with a similar amount of fast charges?

If the earth is round, it's round. It doesn't matter that at one time very few believed it, or that it was an outlier of a theory. That doesn't make a theory wrong. If you're going to attack my theory, you're going to have to do better than that.

 

[JRP3]

With the introduction of 8.0 there was an immediate massive drop in SC speed for the 90 kWh which @Bjorn documented from several users on the norwegian FB group forum. From 110+ kW on 7.* with a drop:

to under 90 or so kW max for a long duration.

In later updates the speed has climbed back up a bit, his car now maxing at 95-96 kW.

Worth noting that even though the peak on the new 90 pack is lower the time spent at a higher charging rate is greater, so peak power may be sacrificed for over all increased charging speed.

 

[phil0909]

Look, if you disagree ... fine. But why such an effort to make it personal?

Go ahead and disagree. Have at it. But you seem to take great offense with the people who express opinions that don't align with your views. When I disagree with you, it's not personal. I have zero need to attack you personally. But I will express a differing opinion if I have one, and will try to do so respectfully.

MasterT's post was not personal, it was merely critical. I happen to think your prior post was fairly reasonable and that MasterT's criticism was unduly severe ("cheerleader-ish" is perhaps not the nicest way to say "insufficiently skeptical"), but that is not the same as personal. You seem well aware of the distinction, since you are the one calling it out. So, I would urge you to re-read the thread and see that you were not personally attacked. At all. You were disagreed with, which is perfectly appropriate in such a discussion, regardless of whose views are closer to the truth.

Let's try to avoid hurt feelings and defensiveness, so we can continue a productive discussion.

 

[bonnie]

MasterT's post was not personal, it was merely critical. I happen to think your prior post was fairly reasonable and that MasterT's criticism was unduly severe ("cheerleader-ish" is perhaps not the nicest way to say "insufficiently skeptical"), but that is not the same as personal. You seem well aware of the distinction, since you are the one calling it out. So, I would urge you to re-read the thread and see that you were not personally attacked. At all. You were disagreed with, which is perfectly appropriate in such a discussion, regardless of whose views are closer to the truth.

Let's try to avoid hurt feelings and defensiveness, so we can continue a productive discussion.

Oh, I don't have hurt feelings. It's a car forum .

To be fair, I was referring to a number of his posts. I only take issue with his continuing unnecessary use of words like 'cheerleader' and 'fanboy' here in this thread and others. It is no better than someone else dismissing opinions by calling people 'trolls' (something I just don't do). Make your argument without using words that you hope will push a button.

 

[NerdUno]

So while others in other threads are complaining that the left hand doesn't talk to the right, somehow in this particular case Tesla managed to 1) decide to put in the time (though bandwidth-constrained) to identify a few people abusing, 2) updated their system to catch them and throttle their charging, 3) communicate throughout the company how to characterize it (battery degradation), and 4) have everyone associated with the issue fall into line.

Personally, I would have just sent a note to those few people if the abuse were severe. But that's just me.

You profess to have great connections to Tesla insiders, and then you post stuff like this. Why not ask one of your experts for an honest answer. Sure beats having it come out in a deposition someday.