If you fast charge, Tesla will permanently throttle charging

[MP3Mike]

All current S/X batteries use the same 18650 cells with the same chemistry - 75, 90, and 100. The 100 uses different modules which pack more cells per module.

And you know that as a fact because? Have you torn down all the packs and compared the cells?

 

[Canuck]

All current S/X batteries use the same 18650 cells with the same chemistry - 75, 90, and 100. The 100 uses different modules which pack more cells per module.

Are you sure about that? Elon Musk said it was for "upgraded packs" back in 2015:

During a conference call, Musk told reporters that “it is, actually, as a result of improved cell chemistry. We’re shifting the cell chemistry for the upgraded pack to partially use silicon in the anode. This is just sort of a baby step in the direction of using silicon in the anode. We’re still primarily using synthetic graphite, but over time we’ll be using increasing amounts of silicon in the anode.”

I think at that time these were new cells being produced, and it was experimental "baby steps", and thus perhaps they were only going into the 90 packs, since there were no 100 packs at that time, and he said it was chemistry for the "upgraded packs".

I hate to throw fuel on the fire (since I don't even really see this as a fire) but I'm not convinced that Tesla stuck with silicone once it appeared the 90 packs were degrading faster than the old 85's. Also, @JonMc from Tesla told us it affects less than 1% of customers so it seems pretty limited in scope. But this is all just pure speculation on my part.

I miss the old days when we could discuss interesting things like this here without dramatic replies equating to Tesla is the devil, or conversely, is a saint, since Tesla is neither. It's just a corporation that is run by humans -- so it's flawed, like the rest of us.

 

[Ugliest1]

I guess my stance is something to the tune of this: Awareness is good. Ignorance is bad.

I do think growing overall understanding in the community is a worthy side-product of data mining such as this.

There is nothing wrong with warranted concern. Quite the contrary, I would say lack of it is equally bad as too much of it.

If avoiding unnecessary DC charging is good for your battery characteristics (like peak rates), then I would rather people knew.

Just my opinion.

Mark Twain said: "We should be careful to get out of an experience all the wisdom that is in it -- not like the cat that sits on a hot stove lid. She will never sit down on a hot lid again -- and that is well; but also she will never sit down on a cold one anymore."

So, "warranted concern", for sure yes. Speculative worrying and blaming Tesla for all sorts of imagined underhanded and nefarious plans is... not so productive.

 

[TexasEV]

Would you agree with my suggested recommendation that going forward DC charging be only recommended to be used when necessary and not if AC can do the trick? Just like the 80-90% rule, to me that would sound like a useful practical advice. No?
.

No I wouldn't. That goes way too far based on the information provided by Tesla. Again I think this is frightening people unnecessarily. That makes it sound like any amount of DC charging could be problem, rather than the problem occurring when someone uses DC charging almost exclusively. And even for the few cars that have had a slightly reduced peak charging rate, it's of little significance compared to all the other variables that affect speed of supercharging.

 

[AnxietyRanger]

@Canuck

Good speculation.

We have the data point of "H packs" being especially vulnerable. Perhaps that would fit silicone used in them? Could it be just them?

Link in summary: If you fast charge, Tesla will permanently throttle charging

As for your lamentation. Unfortunately IMO Tesla can blame itself for a lot of this. The Ludicrous counters were/are a disgrace and there have been others...

 

[AnxietyRanger]

So, "warranted concern", for sure yes. Speculative worrying and blaming Tesla for all sorts of imagined underhanded and nefarious plans is... not so productive

As I said, all I'm concerned with are finding the facts and if those lead to concerns, I seek warranted ones - no more, no less.

Lack of disclosure from Tesla makes that hard at times, but with team work we'll get there.

 

[torvalstrom]

Since you're a self proclaimed "truth seeker," let's see if you can focus on this one item. We have a single semi-scientific test done on a 90kW limited pack vs. a 120kW capable pack. The test was done by @Owner and they did their best to control for the multitude of variables that impact charge rate. They recorded a 5 minute difference, with the 90kW limited pack tapering on a standard curve. If the new limit doesn't affect the tapering curve (that is, its flat and then lines up with the unlimited curve), it should be significantly shorter.

Observational anecdotes of longer or shorter times are not very useful due to the myriad of variables that can affect charge rate. Also, user perception appears to skew to the negative. For instance, OP quoted a ten minute longer charge time on a similar route, but analysis showed 3.5 minutes. This isn't surprising to anyone who has asked a person who was stuck in traffic about the length of their delay. The answer is quite often longer than the actual time. I've certainly been guilty of this bias in estimating.

What makes you think it should be longer? Is it possible it's even shorter? You don't seem to entertain both sides - that is what a truth seeker does. A drama seeker, on the other hand...

Guys, I'm going to jump in again here. I'm not claiming our data is infallible by any means, but please have a look at the dataset in the Google docs link provided by @ODE90D

We've been taking down quite a bit of data while charging.

My next step is finding time, hopefully this week, to do some more charge time calculations on my MS P90DL from before and now.

I used to have the exact charge curve as reported by Bjorn and now have the one detailed in the Google docs sheet.

The difference in minutes lost on a long charge is without a doubt less than only charging for a brief period early in the cycle, which is where the ~20% reduction in charge speed has been placed.

The speed later in the cycle has been increased.

This is also the reason why my lost time is 7 minutes, because I only need to charge in the beginning of the cycle to reach my home and then charge overnight on an 11 kW type 2 charger.

Again, for the avoidance of doubt, I love the fact that Tesla is trying to protect our investment in their cars, but they really should up their communication about these things so we don't have to speculate on whether we're having a technical issue or something else is going on.
It's also waiting the service centers' time when we think we're having battery issues because of a 20% loss in kW while charging.

Tor

 

[Owner]

Since you're a self proclaimed "truth seeker," let's see if you can focus on this one item. We have a single semi-scientific test done on a 90kW limited pack vs. a 120kW capable pack. The test was done by @Owner and they did their best to control for the multitude of variables that impact charge rate. They recorded a 5 minute difference, with the 90kW limited pack tapering on a standard curve. If the new limit doesn't affect the tapering curve (that is, its flat and then lines up with the unlimited curve), it should be significantly shorter.

Yes I did a bunch of supercharging tests back when the superchargers were first out because I wasn't getting quite the advertised numbers (which they did change). Tesla also included responses to my data and questions.

Supercharger Time Test
Charger Test 4, 5 & QA


I also did the aforementioned test with two other drivers that was quoted above.

Charge-off 90kW vs. 120kW

They aren't all that hard to do, but do take a fair amount of time and good record keeping. The hardest part was getting the car accurately down to where you want to start the tests. Nowadays it might be harder as the superchargers are a lot busier than they were in 2014.

 

[jlv1]

I have a 2 month old S. I've made 2 long distance trips to NY: one of 1000 miles (5 SC sessions) and one of 500 miles (2 SC sessions). it seems like I've only seen the SC go over 90 kW once; the rest of the time it tops out at 90 kW. Every time I was at a station where the other A/B of the pair was unused.

Are they all supposed to be 120 kW?

 

[NerdUno]

And some just spew criticism without any critical thinking involved ... if you know whom I mean.

Here's your comment. Didn't see any attempt on your part to confine it to journalists. But perhaps it was inartfully worded or poor reading comprehension on my part.

 

[torvalstrom]

And I'll give you my opinion: Tesla didn't originally have the limits. After they collected the data, they realized if they don't do something, it's going to hurt the batteries even more. They did something (who knows exactly what, and honestly, I don't expect Tesla to tell me or you or anyone. Why would they? If they tell you, they told the world. Then any other car company doesn't have to spend the time or money figuring out what the limits are), but they did it in their usual Tesla way - without communicating well.

So now we have an internet *sugar* storm which about a dozen members* care about, over something that could and should have been a minor issue "Whoops, after looking at even more data, we realized that if you don't put in a minor limit to your charge rate, it'll degrade your battery even faster/catch fire/whatever. We fixed it to protect you, it'll add 5minutes to a SpC stop and only affects 1% of the population on only certain battery packs"

JonMc came out and said something of the sort, but them people started asking for more a lot details, which understandably Tesla doesn't want to reveal.

Done and done.

Max I'm almost completely in agreement with you, the only issue is that a ~20% decrease in supercharging speed is not a minor issue. The five minute element only comes into play if you account for the increase at the later part of the cycle. This is an important part of the effect of the limit.

Obviously not as important as protecting the battery, but not a minor reduction.

Tor

 

[bonnie]

Here's your comment. Didn't see any attempt on your part to confine it to journalists.

Dude. I was replying to your comment about some journalists. It was part of a conversation. I think it's best we just move on. I accept you didn't mean anything by it. I figured that if I replied in kind, you would not take offense either. Lesson learned.

 

[P85_DA]

Just adding my stats here ...didn't get the chance to read all 50+ pages
2014 P85DL w/55k miles
I charge every week on super chargers min of 4 times a week rest of time I use HPWC at home set at 56amps ..live in so cal and charge in desert quite often I'm getting as of last week still up to 120kwh at peak during charges I easily have well over 500 supercharges in two and a half years of owning car ...

 

[thefortunes]

I have a 2 month old S. I've made 2 long distance trips to NY: one of 1000 miles (5 SC sessions) and one of 500 miles (2 SC sessions). it seems like I've only seen the SC go over 90 kW once; the rest of the time it tops out at 90 kW. Every time I was at a station where the other A/B of the pair was unused.

Are they all supposed to be 120 kW?

Many variables can affect SuC rate - your SOC, battery pack temp, ambient temp, handle age, contact cleanliness, etc...

In addition, I have read (too lazy to confirm since it doesn't apply to me) that the 75 kWh packs (and software-limited variations) can only charge at a max of 96kW due to the number of cells.

All of this is discussed in the other (50+ page thread).

 

[Saghost]

Are you sure about that? Elon Musk said it was for "upgraded packs" back in 2015:

I think at that time these were new cells being produced, and it was experimental "baby steps", and thus perhaps they were only going into the 90 packs, since there were no 100 packs at that time, and he said it was chemistry for the "upgraded packs".

I hate to throw fuel on the fire (since I don't even really see this as a fire) but I'm not convinced that Tesla stuck with silicone once it appeared the 90 packs were degrading faster than the old 85's. Also, @JonMc from Tesla told us it affects less than 1% of customers so it seems pretty limited in scope. But this is all just pure speculation on my part.

I miss the old days when we could discuss interesting things like this here without dramatic replies equating to Tesla is the devil, or conversely, is a saint, since Tesla is neither. It's just a corporation that is run by humans -- so it's flawed, like the rest of us.

"Upgraded packs" in 2015 means 90 kWh packs - then they introduced the 75 with 14 of the 90 modules, then they introduced the 100 and told us it used the same cells as the 90.

No, I haven't disassembled the packs personally, but I have no doubt that they are all the same. If they weren't, we would have heard something before this, like when wk057 pulled the first 100 pack apart and showed us pictures of the inside.

 

[Max*]

Max I'm almost completely in agreement with you, the only issue is that a ~20% decrease in supercharging speed is not a minor issue. The five minute element only comes into play if you account for the increase at the later part of the cycle. This is an important part of the effect of the limit.

Obviously not as important as protecting the battery, but not a minor reduction.

Tor

I'm not trying to downplay the issue. It's a real issue which will affect a subset of the Tesla owners. If I had a 90D, it'd affect me too (I don't have a 90D). I said it about 40 pages back, in 2 years, I probably have about 100 supercharging sessions. Family and friends are all over the place, and we take roadtrips a lot in the Model S.

But the 5 minutes should account for total charge. @ohmman did the math, it's 3.5-5minutes depending on how much you charge (0%-100% vs. 10%-80% I think, he can chime in to correct me). So 5 minutes is the worst case for a full charge. You charge less, you get less time added. You don't start with a low SOC, you get less time added. You're paired, you get less time added. etc.

Only the upper limit is currently believed to be capped, which means it will only affect you while you have a very low SOC and are un-paired at a supercharger. So instead of getting the full 110kw for the first X minutes, you'd only get 90kw (or whatever the current limit is).

 

[SMAlset]

I can't imagine that Telsa has ever guaranteed a particular charge rate. Especially since we know that will all depend on a number of factors.

 

[whttiger25]

I have a 2 month old S. I've made 2 long distance trips to NY: one of 1000 miles (5 SC sessions) and one of 500 miles (2 SC sessions). it seems like I've only seen the SC go over 90 kW once; the rest of the time it tops out at 90 kW. Every time I was at a station where the other A/B of the pair was unused.

Are they all supposed to be 120 kW?

You have the 75kwh pack so 90kw is roughly your max. The 90/100kw packs have extra modules in parallel so can take proportionally larger current, as the current is distributed to more modules simultaneously. So don't worry, you're good. One of the advantages of the larger packs from the beginning was always faster supercharging.

Edit: what thefortunes just said. Missed that he was speculating on the cause, but I can confirm it is true. I actually didn't know 96kw was the exact max but it's in line with what I was saying.

 

[torvalstrom]

I'm not trying to downplay the issue. It's a real issue which will affect a subset of the Tesla owners. If I had a 90D, it'd affect me too (I don't have a 90D). I said it about 40 pages back, in 2 years, I probably have about 100 supercharging sessions. Family and friends are all over the place, and we take roadtrips a lot in the Model S.

But the 5 minutes should account for total charge. @ohmman did the math, it's 3.5-5minutes depending on how much you charge (0%-100% vs. 10%-80% I think, he can chime in to correct me). So 5 minutes is the worst case for a full charge. You charge less, you get less time added. You don't start with a low SOC, you get less time added. You're paired, you get less time added. etc.

Only the upper limit is currently believed to be capped, which means it will only affect you while you have a very low SOC and are un-paired at a supercharger. So instead of getting the full 110kw for the first X minutes, you'd only get 90kw (or whatever the current limit is).

Got it! Apologies for the misunderstanding, I agree 100%

I'll post back when I've done a a more detailed comparison of the charge cycles. I only focused on the difference in time specifically for my commute stretch and how much longer I was stuck there now compared to prior to the limit. (Based on GPS logs for arrival/departure)

Tor

 

[suraj1194]

Many variables can affect SuC rate - your SOC, battery pack temp, ambient temp, handle age, contact cleanliness, etc...

In addition, I have read (too lazy to confirm since it doesn't apply to me) that the 75 kWh packs (and software-limited variations) can only charge at a max of 96kW due to the number of cells.

This is anecdotally true for me. I get 94-96 kWh tops. I get it despite my pack being 'old' by average use case standards here. I drive a lot, and am on track to hit a 30K mile run rate in my first year, and already have ~100+ charge cycles. I've also supercharged dozens of times. I still get 95kWh peak rate. I do approximately 60% NEMA 14-50 at home, 30% supercharging and remainder J1772 at workplace locations.