If you fast charge, Tesla will permanently throttle charging

[Veritas1980]

He knows now. Obviously he did not know before being throttled. I think I follow Tesla pretty closely and I did not know before this thread.

An example of Tesla needing to educate us better on this, IMO.

This exact thing goes for me as well.

When I was looking into buying a Tesla, I had no possibility to charge at home or at work. So my plan was to use the charging station at the local petrol station where I can choose between CHAdeMO, CCS and Type 2 (and it is a pay per kWh before I'm branded as a freeloader). I would of course use the CHAdeMO since I bought the adapter and why wait for 16,5 kW when I can get 40-45 kW for the same price? It's not exactly an interesting petrol station to hang out at.

No one at Tesla said this would be bad for the battery when I talked about my plans for charging, no one put it on the website (at least nowhere obvious).

I don't even know if this will effect my charging since I only have a 75, but I'm really happy that they will install AC charging in my garage next month, and I will for sure only use the CHAdeMO when I'm in a hurry.

 

[AnxietyRanger]

There are an infinite number of omissions in the user manual ... although it is already quite a big volume, in part due to fools who try to avoid taking responsibility for their behavior on this pretext you keep falling back on.

Look, I would - seriously - agree with you were this something I would reasonably consider common knowledge. But I honestly look at the brightest minds on TMC and I do not think we knew about this beforehand.

Otherwise we would have been handing out this advice for years now: avoid DC charging unless absolutely necessary, it will slow down. For the life of me, I can not honestly say that has been happening. I am convinced we did not know until now.

And if we - the enthusiasts - did not know, then obviously this has not been clear to the average buyer either. Thus not clear using common sense. And thus it should be disclosed in the materials.

I am not saying this lightly or flippantly. If there was any chance IMO that common knowledge and sense would have helped in knowing this, I would agree with you.

 

[Electricfan]

A 1200 mile trip for the OP is a short trip for him? Jesus. And he still bought an electric car?

That's the strangest comment I've yet read on this forum, and I've been reading it since 2013.

Uhmmm, yes! Its FANTASTIC that he bought an electric car for 1200 mile trips!!!

Please tell me, why do you NOT want people to buy electric cars for 1200 mile trips? Tesla certainly wants us to buy them for specifically and exactly this! Its the whole reason the supercharger network was built.

 

[AnxietyRanger]

That's the strangest comment I've yet read on this forum, and I've been reading it since 2013.

Uhmmm, yes! Its FANTASTIC that he bought an electric car for 1200 mile trips!!!

Please tell me, why do you NOT want people to buy electric cars for 1200 mile trips? Tesla certainly wants us to buy them for specifically and exactly this! Its the whole reason the supercharger network was built.

Narratives can be quick to change when motivations change.

That said, I do think a lot of people could well use a Tesla without ever DC charging it. Like the Bolt, I think it can be very useful too. So this will only affect a portion of the market. Many will do just fine with home or work (ahem... AC) charging and driving within 100 miles of home.

I will certainly be a bit more hesitant to use DC chargers.

 

[Electroman]

That said, if it really is no problem in the big picture, why not just readily describe and disclose?

There is no need for 'disclosure'. Did Tesla state that charging rates would be impacted during high summer temps? Often here at Texas when it is more than 100F (which is most days for two months a year ), I don't close to even 90kW. There are a lot of things of charging rate, charging curve, degradation etc.. that Tesla does not disclose and NEED NOT disclose. They don't guarantee a particular rate of charge, nor do they guarantee a specific range also.

All they state is when new you will get this much range and charging rate, and as the batteries age those numbers will also change. Thats it. Thats good enough.

Are you informing customers of the possible accelerated effects and slowed charging rate

Were you informed that your charging rate will be impacted at very high temps and low temps? Were you informed that at higher SoC the charging rate will be less? So how is this *any* different?

My iPhone only gives me less than half the battery life than what it did when new. Apple never told me anything when I bought it.

Stop nit-picking.

All you guys are doing a dis-service to yourself and the rest of us by making a mountain out of mole-hill. Tesla has been an amazing transparent company, and everything what they have done so far, has been to maximize the life and the health of your car. They are of course learning as we go, as there is simply no precedence to an EV that has lived this long.

Everyone here who is making fanning the flames on this non-issue, are shooting yourself in your foot. Tesla an amazingly open company, who share more than any other company would, would simply go into the shell and provide canned response we typically get from other manufacturers.

 

[Electricfan]

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.

I think you're being very diplomatic. "nice to know" is a little on the understated side. I think your decision to purchase may have been affected if you'd been told the truth we are all now getting May 7, 2017. I'm so disappointed in Tesla.

 

[AnxietyRanger]

@mkjayakumar I have no problem agreeing to disagree on this. IMO Tesla needed (and still needs) to disclose more. Also I do not consider Tesla a transparent company at all.

I acknowledge your opposing opinion that is Tesla has disclosed enough on this topic and that they are in your view an amazingly open company.

It simply rasies the noise ratio so much others get tuned out.

Sorry you feel that way. I am truly just trying to hash out this information and help process it along. Good data is all I'm seeking to help with.

 

[JRP3]

Look, I would - seriously - agree with you were this something I would reasonably consider common knowledge. But I honestly look at the brightest minds on TMC and I do not think we knew about this beforehand.

Otherwise we would have been handing out this advice for years now: avoid DC charging unless absolutely necessary, it will slow down. For the life of me, I can not honestly say that has been happening. I am convinced we did not know until now.

And if we - the enthusiasts - did not know, then obviously this has not been clear to the average buyer either. Thus not clear using common sense. And thus it should be disclosed in the materials.

I am not saying this lightly or flippantly. If there was any chance IMO that common knowledge and sense would have helped in knowing this, I would agree with you.

Actually in the early days many of us assumed that faster charging would be harder on the cells and speed degradation. That's what I always told people, until the work by Prof Jeff Dahn seemed to show otherwise, as did the long term pack capacity studies. Faster charging does not seem to negatively impact capacity though it does seem to impact peak charge rates in some cases.

 

[CuriousG]

Because he saved ~ $600 by sitting at ChadDemo chargers for 150 hours, and he did it for the money. This is the same guy who is now up in arms over the ~ 3 - 5 minutes he now loses on the occasions he uses a SuperCharger.

But at least now the CHAdeMO adapter is paid for. It can only be free juice from now on.... oh wait.

 

[AnxietyRanger]

@JRP3 Thanks for a good point. The interesting bit in the recent information is that there hasn't been really seen battery degradation itself. Just a loss in peak charging rates and thus time - as you acknowledge too. This isn't, seems, battery degradation in the traditional sense (less energy stored)...?

 

[bonnie]

Actually in the early days many of us assumed that faster charging would be harder on the cells and speed degradation. That's what I always told people, until the work by Prof Jeff Dahn seemed to show otherwise, as did the long term pack capacity studies. Faster charging does not seem to negatively impact capacity though it does seem to impact peak charge rates in some cases.

And that is exactly the issue here. "Some cases" turns out to be less than 1%.

It's unfortunate that this thread has such an inflammatory title (and likely is misleading a number of people). It makes it sounds as if Tesla is arbitrarily throttling people who fast charge, rather than slowing the charge rate slightly (like by 5 min) to protect the battery.

 

[JRP3]

Were you informed that your charging rate will be impacted at very high temps and low temps? Were you informed that at higher SoC the charging rate will be less? So how is this *any* different?

Temporary variables are different than permanent changes. I'm well informed about the behaviors of lithium cells under various conditions, but most people are not, so yes Tesla should educate them so there are no surprises. Since Tesla is actively encouraging people to use superchargers as much as they want they should inform them of potential negative, permanent effects of that use.

 

[jdw]

I was told the opposite of this in 2013 when I bought my first Tesla - supercharging would not have any effect on battery life is exactly what I was told. "

In 2013 the maximum SC rate was 90kWh. Tesla subsequently increased that rate to a maximum of 120kWh, but not every car can charge at that rate - older battery packs, smaller battery packs and now apparently battery packs that have been DC fast charged hundreds of times. The original 90kWh initial charge rate is still slower than most of the reduced taper charging being discussed here and the net time to charge with the new taper is likely lower.

Look, I would - seriously - agree with you were this something I would reasonably consider common knowledge. But I honestly look at the brightest minds on TMC and I do not think we knew about this beforehand.

I think everyone here who cared enough to read or contribute to this forum is/was aware that temperature, range charging, high SOC epecially in high ambient tempertures, natural cell aging and number of charge cycles would have an effect on the battery life and capacity.

Also, that DC fast charging developed a fair bit of battery heat - the fans are hard not to notice ...

 

[thefortunes]

Serious questions for those who are so disappointed that Tesla did not disclose this before they bought their car...

Do you think it is possible that Tesla is continuing to evaluate the impact of all types of activities on battery health?

Do you want them to make changes necessary to protect the health of your battery? (I guess this has already been answered by the OP who said he would opt out of such protection to save 5 minutes).

If, in fact, this (whether it is something related to CHAdeMO or the specific battery pack iteration) is something that they have now discovered would you want them to ask every owner (of that pack, or that is using CHAdeMO) whether they want to opt-in or out? Or take the approach they apparently have chosen which is to protect the pack?

Edited to add: Just spoke with my brother - I have been wrong all this time. He actually has over 150k mile on a D pack, > 95% of those miles were recharged via SuC, and he still sees up to 120kW charge rates.​

 

[JRP3]

@JRP3 Thanks for a good point. The interesting bit in the recent information is that there hasn't been really seen battery degradation itself. Just a loss in peak charging rates and thus time - as you acknowledge too. This isn't, seems, battery degradation in the traditional sense (less energy stored)...?

My guess is possibly fast charging causes thickening of the SEI layer which somewhat slows ion transfer into the electrode during charging, which shows up as increased resistance, but does not affect the capacity for ion storage. Think of it as putting a smaller doorway to a room but the room is the same size.

 

[AnxietyRanger]

Serious questions for those who are so disappointed that Tesla did not disclose this before they bought their car...

Good questions, @thefortunes. I appreciate you taking the time.

My answers:

Do you think it is possible that Tesla is continuing to evaluate the impact of all types of activities on battery health?

I do. In fact I believe the throttling may be the result of Model S/X and/or Supercharger firmware changes in recent times and may not have always existed in this form.

Do you want them to make changes necessary to protect the health of your battery? (I guess this has already been answered by the OP who said he would opt out of such protection to save 5 minutes).

As a primary rule, I would expect Tesla to fix product defects under warranty, if the product features and recommendations significantly changed from what was bought towards the worse. If they find out an issue with the product afterwards, my first preference would be for them to just fix it without otherwise diminishing my purchased product.

I.e. improving longevity is fine, but if that happens at the cost of performance, that would not be my first choice. There of course is some industry precedence that fixing one parameter can not cause missing other parameters because of it (e.g. fixing emissions can not cause performance degradation).

If, in fact, this (whether it is something related to CHAdeMO or the specific battery pack iteration) is something that they have now discovered would you want them to ask every owner (of that pack, or that is using CHAdeMO) whether they want to opt-in or out? Or take the approach they apparently have chosen which is to protect the pack?

At the very least I would expect Tesla to inform me before any material changes. That, I would think, is the bare minimum and in many cases I would just settle with that.

 

[TexasEV]

I was told the opposite of this in 2013 when I bought my first Tesla - supercharging would not have any effect on battery life is exactly what I was told.

And it still doesn't have any effect on battery life-- meaning capacity-- meaning range. Which is what you were concerned about when you asked the question, right? The fact that it may take a few minutes longer to supercharge if you supercharge so much that you're above the 99th percentile of supercharger use has nothing to do with battery life. And since superchargers with peak power above 90kW didn't even exist in 2013, just what was Tesla supposed to tell you? That if they developed a supercharger that started off at higher power for the first few minutes of charging when starting at a really low state of charge, and your battery has experienced more supercharging than what 99% of owners have used, then your car won't be able to take that higher power for a few minutes that doesn't currently exist now anyway? Is that what you're saying that Tesla didn't warn you about when you asked if supercharging would affect battery life? Give me a break.

 

[ohmman]

It's unfortunate that this thread has such an inflammatory title (and likely is misleading a number of people)

Inflammatory or not, it's definitely not accurate. Something more like "Frequent DC charging may reduce future maximum fast charge rates" would be more accurate.

 

[scottf200]

Scott - do you happen to know which firmware you were on for each (or can you get that info)?

Took a little work to drill through data but I updated my original post along with all my firmware upgrade history: If you fast charge, Tesla will permanently throttle charging

7.1 -- 2.13.120 -- 935 mi -- Fri Mar 11 2016
7.1 -- 2.13.120 -- 4009 mi -- Fri May 13 2016
7.1 -- 2.30.61 -- 14600 mi -- Fri Aug 19 2016
8.0 -- 2.44.121 -- 20700 mi -- Tue Nov 15 2016

Also (I suppose I could do the math but...) since the later charges have a shallower taper, is the net effect about the same?

I haven't noticed any difference in time but I don't think I would notice 5 minutes at my charging breaks. I'm not that intensely rushed.

 

[Electroman]

Temporary variables are different than permanent changes

Here is some news for you. There are a number of variables that permanently degrade your battery.

Battery cycling (aka number of miles), calendar (aka age). And here is another shocking news for you - some battery packs degrade more than others. So if you have two packs that have cycled 1000 times in 3 years, they both may or may not have exactly the same range and the same charging rate.

Were you told about any of those things when you bought the car? Did someone give you the degradation curve and charts and probability analysis ? All you were told - which you knew already - and the range and the charging times are good to go when new, and batteries degrade over time and miles.

This is no different from that.