Tesla may have fast charging hard cap, Supercharging speeds permanently reduced

bro1999 · 2017-05-04

https://teslamotorsclub.com/tmc/posts/2088343/ An owner of a Model S has received official confirmation from Tesla that ALL Tesla's now have a hard count of how many fast charging sessions are allowed (Supercharging OR via CHAdeMO adapter). Once the hard count is reached, max Supercharging speeds are PERMANENTLY reduced FOREVER. Wow! If I was a Tesla owner I'd be pissed! Never being told about this restriction up front. Supercharging not what it used to be, eh?

scottf200

· #6 · May 5, 2017 (Edited)

Almost 32,000 miles on my 14 month old Tesla Model X with quite a few supercharges on roadtrips.

The below from last weekend is pretty good, right? I'm still getting 100+ kW at various SCs depending on my starting SOC.

bro1999, remind me again what your Bolt is getting (44 kW?) :0 -- you are a little overboard on the Tesla bashing aren't you

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scottf200

· #22 · May 5, 2017 (Edited)

DonC said:
<snip>
We'll get more information. Might even turn out the poster is FOS. In any event, assuming there is a limit, as mentioned above, I doubt many Tesla owners will ever hit a limit. So not a big deal one way or the other. The bigger deal would be if the DC charging is actually effecting the chemistry. From all we know this seems unlikely but it's possible.

It appears that the poster has done over 240 chademo charges in the past year and 50+ supercharges. Perhaps they have a free chademo charging station near their work and they are just trying to drive for free (and blocking a charger). I don't know but that scenario is easy to see based on the count. I think they are also down to 90 kW charging which is still a lot because charging at higher kW tapers fairly quickly anyway.

I would not be surprised or concerned if Tesla manages the battery charging as it ages ... from some of my charging graphs (at same supercharge on a trip I take regularly (kid at college) I get sustained charging in the 75-80 kW for quite a while tapered down from 100+ kW. Maybe as it ages they just don't start out at max kW but have longer sustained kW levels like I see on my graphs in the past 14 months and ~32K miles. But I'm only using a sample of 5 at this one location.

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scottf200

· #39 · May 6, 2017 (Edited)

Conflicting info compared to the OP that has done 240+ chademo and 50+ supercharges this past year.

https://teslamotorsclub.com/tmc/thr...-throttle-charging.90230/page-17#post-2090080

thefortunes said: I mentioned my brother a "few" posts back (who knew this thread would get this long?).

He has >130k miles on his S and estimates that he has SuperCharged 95% of those miles (typically twice a day on his 300 mile commute). Charged yesterday at 112kW.

bro1999 said:
What we know for sure is that a 2015 P90D owner has experienced degraded Supercharging, and a Tesla engineer in MO documented that the degraded SC rates are normal and that the owner's Tesla has had Supercharging ability PERMANENTLY REDUCED. There is no disputing those facts.

The OP claims he is current getting 90kW charging. If you look at my charging at this one site I got in in a common trip I take you can see how much time I spend above 90kW. The OPs charging would only increase by what 5-7 minutes? Compare this to him charging at 44kW max.

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scottf200

· #41 · May 6, 2017 (Edited)

bro1999 said:
And op also said he used to get 115. 90<115 last time I checked.

That is why I stated current in this statement: "The OP claims he is current getting 90kW charging."

If true, then again how much extra time would this take him to actually charge?

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scottf200

· #43 · May 6, 2017 (Edited)

bro1999 said:
25 kW is 25 kW. Because it's only realized for 5-10 minutes a charge session, it's okay to be taken away? I guess you would be fine if Tesla pushed out a firmware update reducing HP by 50 to increase power train life too, huh?

The main point of contention is that Tesla is doing these under the hood changes without telling their customers. When's the last time GM or anyone else put out an update that reduces the speed someone can fill their gas tank?

OK, so it may take him 5-7 extra minutes while he is on a roadtrip ever few hours. This does not affect his almost daily chademo charging.

So even if all the above is true is it better for Tesla to push the limits and have the BMS manage the battery as they known chemical changes are degrading the battery? Perhaps they should just limit it to 90kW max (44kW, 60kW, or whatever, etc) from the beginning?

By comparison GM charging is ultra conservative. There are pluses to that but there are negatives and ramifications (perception of leader, sales, extra time spent by customers charging (way more than 5-7 minutes), realistic limiting usage to city cars for average buyer, etc, etc).

Certainly the GM BMS has software to handle aging and chemistry changes in their battery management. Is this documented? I think my 2011 Volt battery certainly has undergone aging and chemical changes in 5.5 years. I don't recall reading how they changed the BMS functionalty or window of the battery SOC over time. GM keeps all these technical things to themselves. I'm amused that people are not acknowledging this. Is the battery management documented for the Bolt and what happens after X months or years or what happens after Y miles (in different increments) ?

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scottf200

· #45 · May 6, 2017 (Edited)

scottf200 said:
OK, so it may take him 5-7 extra minutes while he is on a roadtrip ever few hours. This does not affect his almost daily chademo charging.
<snip>
Certainly the GM BMS has software to handle aging and chemistry changes in their battery management. Is this documented? I think my 2011 Volt battery certainly has undergone aging and chemical changes in 5.5 years. I don't recall reading how they changed the BMS functionalty or window of the battery SOC over time. GM keeps all these technical things to themselves. I'm amused that people are not acknowledging this. Is the battery management documented for the Bolt and what happens after X months or years or what happens after Y miles (in different increments) ?

bro1999 said:
So you are ok with Tesla downgrading performance without informing customers beforehand if it's in the name of reducing failures (and warranty expenditures). Oooooook, Tesla is lucky to have such understanding customer's as yourself.

You are not acknowledging my question about what GM does in informing the customers about the details. Why give them a pass?

I'm OK with GM managing my battery for longevity in the 3 Volts my family has. Same as I'm OK with Tesla managing my battery for longevity.

Again, did GM document to you how they are managing your Bolt's kW power flow over a single charge? Do they start at 44kW and keep that rate until you stop the charge? Or does the BMS manage that rate? Is it documented? Will it change over the life of your battery? Is it documented?

Again, did GM Bolt document to you how they are managing your Bolt's kW power flow over X number of DC charges or Y months? Do you think it will remain the same from day 1 to year 10? Is it documented?

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scottf200

· #46 · May 6, 2017

For those wanting more details on internal cell resistance, cell aging, etc, see this guys presentations and work. https://www.google.com/search?q=Jeff+Dahn+battery

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scottf200

· #50 · May 6, 2017 (Edited)

bro1999 said:
GM hasn't (in the...7 vehicles I've possessed over the years) applied an update without my knowledge that degraded the performance of my vehicle like Tesla has done once already (ludicrous launch limiter), and likely again with the fast charging hard cap limit.

GM states that I can charge up to 25 miles an hour @ 240V/32 amp EVSE, and up to 90 miles in 30 minutes when hooked up to a 80 kW fast charging station. I've realized the 25 miles/hour figure, but I have yet to realize 90 EPA miles in 30 minutes, but then again I have only used a 50 kW max DCFC station, not 80. I'm not even sure why you are even bringing up the Bolt, because we are talking about Tesla's (loose) business practices here.

Looking at the thread on TMC again, I see more people have come forward stating they have been "SC neutered" as well. Tesla better state some official soon before the crap hits the fan.

GM electric cars do not have magic batteries that don't degrade and can take the same kW charging throughout their expected life.

I brought up the GM and their charging because everyone has to manage the battery and they have software that changes the kW over the time of one charge cycle and over longer term (X number of DC charges or months) to manage the battery. GM is not documenting what they are doing for either of these.

Key point: Your charging and battery capacity will degrade over time no matter whether you get an update (USB stick at dealer?) or not if it was already built into the software or "neutered" from the very beginning.

I think 5-7 extra minutes every few hours and 90kW max is hardly "SC neutered". I'm not doubting they are managing the battery as they see different realworld use cases. The OPs 240+ chademo and 50+ SC could have triggered lowering maximum kW. If that what Tesla determined is good for the longevity of our batteries then I trust them just like I trust GM to manage the battery in our 3 Volts.

It will be interesting to see the Bolt charging progress / progression. I look forward to the real world examples that it will be higher (I've seen doc stating 80 kW max charger whatever that means for max car kW). I would like to see GM presentations or documentation showing the charging graphs throughout a single charge (i.e. kW max and taper) and what they expect them to look like over 10 years. GM has predicted this and built it in the software already I am sure. They are not explicating providing the technical details for it tho.

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scottf200

· #51 · May 6, 2017 (Edited)

bro1999 said:
Tesla Bjorn has also confirmed his S has suffered SC rate neutering.

Here is a video where he is showing the new 90 kWh battery does have a lower max kW but charges *longer* at a higher kW during the tapering. JRP3 also pointed this out on TMC: "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."

https://www.youtube.com/watch?v=rBfpCnBeX5Q

As it related to this thread ... Bottom line is max kW does not mean significant changes especially if they can maintain longer kW rates during the taper. You can see from my chart in previous post that my car is maintaining an ~80 kW rate for a 'long' period of time.

Again max kW does not tell the whole story. You need to see what the taper looks like and if that has changed (higher kW for longer). Hence the reason I keep referring to these types of charts and documentation.

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scottf200

· #54 · May 6, 2017 (Edited)

2

alfon said:
About 3 blocks from my house in Seaside, Oregon, Tesla placed a large charging station, I believe 6 units or so,
<snip>
I guess its placed there for the Tesla owners driving the Oregon Coast via Highway 101, to stop and top off their batteries. It seems like this Tesla charging station just appeared one day, amazing....

Yes, the number of superchargers are being doubled this year (grey placemarkers). The number of pedestals (units in your term) per supercharging location is increasing as well (10+ at busier locations). The Tesla cars 'trip planner' will route you from supercharger to supercharger on such trips. You do not have to fill all the way up as it tells you when you can continue your trip when you have about at 12%-15% extra buffer to make the next one. Lunch, bathroom breaks, etc.

Thread related: A key point is you don't have to fill all the way up so you are often charging in the early/fastest part of your battery SOC. In my example I'm getting a sustained ~80kW (i.e. below the 90kW max for the user being talked about).

It looks like Tesla is hoping to finish I5 that runs parallel with 101 you mention this year. The grey placemarkers in the below pictures are what is 'planned' for 2017. This was added to the 'findus' interactive map just a couple weeks back. Before it was a static image.

Interactive (zoomable) map here https://www.tesla.com/findus. For just a supercharger type of view click the destination button at the bottom of the page to remove destination chargers (i.e. hotels).

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scottf200

· #56 · May 7, 2017

jupitermoon said:
Scott, I scoured the net for a bit and I find absolutely no evidence that Tesla has throttled back any supercharger speed. It seems to be an issue/circumstance of individual owners and cars. Supercharger speed variations have been recorded since mid-2016 it seems from posts I've found of owners online. Here's a very late and recent posting of an owner who has had slower than usual charging rates similar to owners dating back 8-10 months from now.

https://forums.tesla.com/forum/forums/slow-supercharger-speeds

Thanks!

1 of 2: The kW rate various by car per a set of fixed information regardless of age or amount used. ie. version of battery pack (chemical changes), size of pack (60kWh owners would not see 100+ kW even when new as an example; 95ish max?), starting SOC %, curr temp and cooling of battery throughout charging, temp and cooling of electronics at supercharger throughout charging, etc, etc.

2 of 2: The kW rate certainly has variable changes based on how the BMS is programmed (above factors, current resistance, age, taper). Re: resistance -- I know with A/C charging I've had my amps drop overnight at an AirBNB when the voltage changed overnight.

I don't think it is related to supercharger although that must vary by time of day and voltage for particular transformer locations. My house '240' voltage various a far amount during the day but is pretty steady at night.

I would be surprised if it was a 'counter' but would not be surprised if they did change the kW based on other factors as the battery ages (calendar and usage). My 1 calendar year old car 'aged' 2 years and I recently got both my 1st+2nd annual service based on how many miles I put on it. The service center was great in how they handled the work and cost.

This guy on TMC is the opposite of the owner having a problem (see underlined text especially):

yobigd20 said:
I find this thread interesting, because the OP says he only has 30k miles and has encountered this "throttling". I have 148k miles. My daily commute I cannot make it to work and back on a single charge. I range charge to 100% every morning I go to work (I have to, or else I wont have enough left to make it to the supercharger in order to get home), and I supercharge almost every day during the week, sometimes twice a day. Twice a week it can even be 3x daily. I've been doing this for 4 years now. The number of times I supercharge is ridiculous, probably more than anyone else ever has. There's no way the OP has even come close to the number of times that I supercharge. Yet I have experienced no throttling and always observe around 117-118kWh during the beginning of charging. It does take about 30-40 minutes to go from 0-80% and from 80-100% can be another 30-40 minutes. This is normal AFAIK.

Logically thinking a simple "counter" every time you plug in wouldn't make sense from an implementation perspective either since it doesn't differentiate the difference between a 1% charge and a 99% charge. This would imply that if I sat there and all I did was plug in unplug plug in unplug plug in unplug for hours on end even though it is not really gaining any charge I'd hit the threshold and suddenly be throttled even though my battery state remained the same. <snip>

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scottf200

· #61 · May 7, 2017 (Edited)

saghost said:
So GM told you that it would charge slower than a Spark EV and start throttling around 50% SoC in big steps?

I must have missed that thread. The only thing I remember GM communicating was the 90 miles in 30 minutes, and I remember a whole lot of speculation here about how much faster the car might charge.

Not saying a hidden counter is acceptable if such a thing actually exists, but I don't feel like either company has communicated clearly on the subject

Source for the underlined text is bro1999's own blog post https://bro05.blogspot.ca/2017/03/fast-charging-experiences-with-bolt.html :

The Bolt tapers the max charge rate fairly early compared to say the Spark EV.
While Spark EV owners reported near 50 kW rates from 0% to almost 80% SOC, I've noticed the Bolt starts tapering rates at
around 50% SOC (ramps down to ~38kW/~100 amps) and
again at 70% (down to ~24 kW/~60 amps) from peak ~46 kW/125 amp charge rates at a 125A station.
At a little over 80%, the rate again tapers down to <20 kW and stays there till fully charged.

The Tesla owner 90kWh battery cars case in question is currently getting 90 kW charging rate max. In my 90kWh battery car case, I taper down over 10 minutes and stay at 80 kW for 20 minutes see this chart.

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scottf200

· #66 · May 7, 2017

Ladogaboy said:
The integrated trip planner is something that could easily be done through Google Maps. I'm not really concerned about it, truthfully. I check my fuel level, look at the route I'm going to take, and I drive to my destination. Never really needed my hand to be held.

But is everyone like you and is that they way to appeal to a large mass of customers? Without the smarts of a 'trip planner' people often think they need to charge up to 99 or 100% when 80 or 85% will leave plenty of buffer and charge to MUCH faster.

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scottf200

· #67 · May 7, 2017 (Edited)

Chris TX said:
So it looks like any peak charge rate slow down is due to Tesla keeping on top of the cell's physical chemistry. This is the same thing that happens when the cells are cold, or the level is too low. Considering it's a rare thing like Scott pointed out, to have the stars align anyway for a charge session that sees 120kW for only a few minutes, I don't see it as being a big deal when my car gets to that point in its life. Who knows, maybe I'll swap in a 100kW battery or something by the time that happens.

https://electrek.co/2017/05/07/tesla-limits-supercharging-speed-number-charges/

As people thought: "...after a very large number of high-rate charging sessions. This is due to physical and chemical changes inside of the cells. ... may increase total Supercharge time by about 5 minutes" ... 5 minutes ... ho-hum. Maybe something else will pop up in the next couple days beside the below but so far fairly benign especially if they sustain a reasonable kW rate now (which is obviously less than the max as in my charts example).

In a statement, Tesla explains that it is a software limitation to optimize for the best possible owner experience that’s within the limits of physics. Here’s the [Tesla] statement in full:

“The peak charging rate possible in a li-ion cell will slightly decline after a very large number of high-rate charging sessions. This is due to physical and chemical changes inside of the cells. Our fast-charge control technology is designed to keep the battery safe and to preserve the maximum amount of cell capacity (range capability) in all conditions. To maintain safety and retain maximum range, we need to slow down the charge rate when the cells are too cold, when the state of charge is nearly full, and also when the conditions of the cell change gradually with age and usage.

This change due to age and usage may increase total Supercharge time by about 5 minutes and less than 1% of our customers experience this.

Tesla is not slowing down charge rates to discourage frequent Supercharging – quite the opposite. We encourage our customers to use the Supercharger network at their discretion and we committed to doubling the number of worldwide chargers just this year. We also want to ensure that our customers have the best experience at those Superchargers and preserve as much vehicle range as possible – even after frequent usage.”

Click to expand...

[update]
Above text is from the article but JonMc (Tesla) posted it on the TMC forum as well. https://teslamotorsclub.com/tmc/posts/2092107/
JonMc is Tesla’s president of Global Sales and Service, Jon McNeil.
[/update]

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scottf200

· #69 · May 8, 2017 (Edited)

bro1999 said:
So it's confirmed that Tesla does permanently reduce SC rates after so many DCFC sessions. JonMc also did not dispel the DCFC hard counter belief, nor to he address if CHAdeMO charge sessions (can be as low as 18 kW) have an impact on the eventual SC max rate neutering.

Jon McNeil -- Tesla’s president of Global Sales and Service:

... To maintain safety and retain maximum range, we need to slow down the charge rate when the cells are too cold, when the state of charge is nearly full, and also when the conditions of the cell change gradually with age and usage.

This change due to age and usage may increase total Supercharge time by about 5 minutes and less than 1% of our customers experience this. ...

5 minutes -- ho-hum

Compare the charging time (with slow down even) of a Tesla Model 60 to a Bolt 60. How much longer is the Bolt to charge with it's rapid neutered slowdown? Starting at 25% or 50%(!).

Reminder: bro1999's own blog post https://bro05.blogspot.ca/2017/03/fast-charging-experiences-with-bolt.html :

The Bolt tapers the max charge rate fairly early compared to say the Spark EV.
While Spark EV owners reported near 50 kW rates from 0% to almost 80% SOC, I've noticed the Bolt starts tapering rates at
around 50% SOC (ramps down to ~38kW/~100 amps) and
again at 70% (down to ~24 kW/~60 amps) from peak ~46 kW/125 amp charge rates at a 125A station.
At a little over 80%, the rate again tapers down to <20 kW and stays there till fully charged.

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scottf200

· #75 · May 8, 2017 (Edited)

bro1999 said:
As a person that at one time considered a Tesla purchase, I now feel justified in spurning "big T" for the Bolt.

What is hilarious is that more and more Tesla owners are making posts lamenting Tesla's lack of transparency. But I guess people like you that have the Tesla-shaded blinders on, transparency is not a concern. Good for Tesla to have such customers that don't ever complain about anything and just keep on chugging the Tesla red kool aid.

What I find hilarious is we are talking about 5 minutes.

How many minutes did charging or dealing with charging take you here? : https://bro05.blogspot.com/2017/04/attention-to-detail.html

Everything is relative and the Tesla pros and ongoing improvements to the car (OTA) as well as the SuperCharger network (doubling this year) outweigh the cons ... by far. The people with issues are using DCFC to the max. Even buying the car and using the maximum range and not accounting for known degradation due to physics and chemistry.

It is not like GM is documenting or telling Bolt owners about degradation over time and how their BMS algorithms will slow down the charging ... but certainly they had to account for that ... because their batteries are not magical defying physics and chemistry. Try doing CCS DCFC almost everyday and let us know how your battery holds up.

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