If you fast charge, Tesla will permanently throttle charging

[hill]

Tesla explains why it limits Supercharging speed after high numbers of DC charges

don't wana get anyone's shorts all bunched up because I'm (God forbid) referring to an old link, but there is part of that dialogue I've been ruminating on for some time now - which STILL leaves unanswered questions;

"... According to Tesla engineers, once vehicle has been DC fast charged over a specified amount, the battery management system restricts DC charging to prevent degradation of the battery pack. According to Tesla engineers, this vehicle has seen significant DC fast charging and is now has permanently restricted DC charging speeds. Important to note, supercharging will always still be available to the vehicle and the battery pack has not yet experienced significant degradation due to the amount of DC fast charging performed on the pack up until this point in time. Vehicle is operating as designed.

The news that a limit has been placed on DC fast-charging has sparked some outrage among Tesla owners in the thread, but to be fair, this particular Tesla owner has been virtually only charging through DC fast-charging, which is not common amongst electric vehicle owners.
He said that he accumulated [] charge ups on CHAdeMO only –..... "

Tesla's response here still fails to say how many kWh are necessary to hit the Throttle Down threshold experience ... and if Tesla had been forward-thinking enough to give notice to owners of this inevitable action right from the get-go, folks nearing that threshold, whatever it is - could be proactively attempting to avoid it - or even take a different charging tactic right from the get-go.
Tesla also failed to say whether or not this amount of supercharging stems from kWh's supercharged (or lower rated CHAdeMO'd) from recharging all the way to the top, or above 80%, above 50% or whether it's any amount of kwh received upon DC hook up. For example, we regularly use CHAdeMO - but it's typically just to bring a 15% charge back up to 50% ... maybe 33kWh's total each time .... and this CHAdeMO we use is only charging at 48kWh (most have that as a near max) .
one can easily understand that 100 kwh speed will heat up a battery, especially at the upper end. but 48 kwh? on the bottom end? that's going to ultimately at some point STILL cause a permanent throttle-down? from Tesla's nebulous explanation, it would appear so - because they only seem to date a criteria of total amount of a kWh's. the very reason we've stayed away as much as possible from upper end & 100 kWh speeds, was primarily to Preserve traction pack longevity. But now it looks like all bets are off because Tesla in their wisdom have taken their own measures. Wonder why they haven't given more specifics ....
.

 

[JeffK]

don't wana get anyone's shorts all bunched up because I'm (God forbid) referring to an old link, but there is part of that dialogue I've been ruminating on for some time now - which STILL leaves unanswered questions;
Tesla's response here still fails to say how many kWh are necessary to hit the Throttle Down threshold experience ... and if Tesla had been forward-thinking enough to give notice to owners of this inevitable action right from the get-go, folks nearing that threshold, whatever it is - could be proactively attempting to avoid it - or even take a different charging tactic right from the get-go.
Tesla also failed to say whether or not this amount of supercharging stems from kWh's supercharged (or lower rated CHAdeMO'd) from recharging all the way to the top, or above 80%, above 50% or whether it's any amount of kwh received upon DC hook up. For example, we regularly use CHAdeMO - but it's typically just to bring a 15% charge back up to 50% ... maybe 33kWh's total each time .... and this CHAdeMO we use is only charging at 48kWh (most have that as a near max) .
one can easily understand that 100 kwh speed will heat up a battery, especially at the upper end. but 48 kwh? on the bottom end? that's going to ultimately at some point STILL cause a permanent throttle-down? from Tesla's nebulous explanation, it would appear so - because they only seem to date a criteria of total amount of a kWh's. the very reason we've stayed away as much as possible from upper end & 100 kWh speeds, was primarily to Preserve traction pack longevity. But now it looks like all bets are off because Tesla in their wisdom have taken their own measures. Wonder why they haven't given more specifics ....
.

It likely depends on a number of factors and there may not be one magic number..

 

[davidc18]

We are also interested in getting a better more information from Tesla. As usual, what they have provided does not help the owners much at all.

 

[JeffK]

We are also interested in getting a better more information from Tesla. As usual, what they have provided does not help the owners much at all.

The owners of Model 3s? They have a printed user manual already. Oh, and an actual car.

 

[davidc18]

uh - no - see the photo? MS/MX owners.

 

[David99]

Tesla's response here still fails to say how many kWh are necessary to hit the Throttle Down threshold experience ...

Battery degradation is not digital. It's not a certain threshold and then something happens. It's a gradual process and many things affect it more or less and multiply each other in combination.

 

[apacheguy]

Battery degradation is not digital. It's not a certain threshold and then something happens. It's a gradual process and many things affect it more or less and multiply each other in combination.

All true, but the reduction in charging rate due to the DC charge counter is not simply due to degradation. There is (as I understand it) an actual switch in the firmware that will forcibly and permanently reduce the charge rate.

 

[David99]

All true, but the reduction in charging rate due to the DC charge counter is not simply due to degradation. There is (as I understand it) an actual switch in the firmware that will forcibly and permanently reduce the charge rate.

On some batteries yes, that seems to be the case. But they might change that again with a new firmware and maybe make it a more gradual reduction depending on use. I think that's the only thing that makes sense.

I also cannot see how Tesla would reduce the charge rate on the Tesloop cars. That would seriously affect them. But it seems Tesla gives Tesloop special treatment.

 

[apacheguy]

Does Teslaloop have any 90/100 kWh models? If they have 85 kWh then it makes sense that they are not affected.

 

[stopcrazypp]

don't wana get anyone's shorts all bunched up because I'm (God forbid) referring to an old link, but there is part of that dialogue I've been ruminating on for some time now - which STILL leaves unanswered questions;
Tesla's response here still fails to say how many kWh are necessary to hit the Throttle Down threshold experience ... and if Tesla had been forward-thinking enough to give notice to owners of this inevitable action right from the get-go, folks nearing that threshold, whatever it is - could be proactively attempting to avoid it - or even take a different charging tactic right from the get-go.
Tesla also failed to say whether or not this amount of supercharging stems from kWh's supercharged (or lower rated CHAdeMO'd) from recharging all the way to the top, or above 80%, above 50% or whether it's any amount of kwh received upon DC hook up. For example, we regularly use CHAdeMO - but it's typically just to bring a 15% charge back up to 50% ... maybe 33kWh's total each time .... and this CHAdeMO we use is only charging at 48kWh (most have that as a near max) .
one can easily understand that 100 kwh speed will heat up a battery, especially at the upper end. but 48 kwh? on the bottom end? that's going to ultimately at some point STILL cause a permanent throttle-down? from Tesla's nebulous explanation, it would appear so - because they only seem to date a criteria of total amount of a kWh's. the very reason we've stayed away as much as possible from upper end & 100 kWh speeds, was primarily to Preserve traction pack longevity. But now it looks like all bets are off because Tesla in their wisdom have taken their own measures. Wonder why they haven't given more specifics ....
.

I posted elsewhere, but I suspect it is not a hard kWh number cutoff, but rather something that measures how much per unit time you are charging (or example how many kWh per year DC charging) and it adjusts such that it can keep degradation the same under the warranty period.

For example someone who charges 6000kWh of DC charging in less than a year, might be throttled, but someone who takes 4 years to do so might not be. Using a hard kWh cut-off fails to account for this.

 

[Wesleyraz]

I will sell my XP100 if it keeps supercharging for more than 2 hours and never reccomend it to anyone

That's crazy

 

[navinsiri]

I will sell my XP100 if it keeps supercharging for more than 2 hours and never reccomend it to anyone

That's crazy

Thats probably not throttling it's probably issues with the supercharger
See this: charging slow at Superchargers

 

[AmpedRealtor]

I will sell my XP100 if it keeps supercharging for more than 2 hours and never reccomend it to anyone

That's crazy

I have a much simpler solution: Move to another stall. What you are describing is a problem with the Supercharger, not the car.

 

[uisynot]

I have been able to reproduce this issue at a supercharger recently. Tried all 10 stalls, and all of them start at 94kw (about max for a s75) and quickly drops to 40kw within a few mins exactly. All of them had the same behavior. The weather was around 100 degrees though so heat may have been an issue but I've had this issue at night in the 70s too.

Either Tesla is secretly throttling (to deter supercharger use) or something is wrong and they haven't been able to figure it out.

 

[Rocky_H]

I have been able to reproduce this issue at a supercharger recently. Tried all 10 stalls, and all of them start at 94kw (about max for a s75) and quickly drops to 40kw within a few mins exactly. All of them had the same behavior. The weather was around 100 degrees though so heat may have been an issue but I've had this issue at night in the 70s too.

Either Tesla is secretly throttling (to deter supercharger use) or something is wrong and they haven't been able to figure it out.

No, that is a different issue. The issue in this thread is capping of the car at the top end--the highest rate being lowered from about a hundred and some to 90. What you are experiencing, where it starts off fairly high, and then drops down to 40 or 50kW is a problem with the cables/handles getting too hot. Several of the Superchargers have some handles that are a bit worn and overheat, which causes them to drop their rate to about 40kW. As those handles get replaced, if fixes those.

 

[uisynot]

No, that is a different issue. The issue in this thread is capping of the car at the top end--the highest rate being lowered from about a hundred and some to 90. What you are experiencing, where it starts off fairly high, and then drops down to 40 or 50kW is a problem with the cables/handles getting too hot. Several of the Superchargers have some handles that are a bit worn and overheat, which causes them to drop their rate to about 40kW. As those handles get replaced, if fixes those.

That makes perfect sense and yes, when I went out to take the plug off, it nearly burned my hand. It would have if I didn't get my hand off of it right away. Interesting thing is that this supercharging station is new, built within the last year.

Thank you for the information.

 

[hill]

I have a much simpler solution: Move to another stall. What you are describing is a problem with the Supercharger, not the car.

doesn't that presume all stations aren't being camped at? Or that the remaining open 2 or 3 stalls weren't already abandoned by those who arrived before you, due to them being in dire need of cable/nozzle replacement? nothing more exasperating than moving 2 or 3 times, only to find equally poor maintenance on remaining open stalls. mentally you regret moving, as it ends up being time wasted as you could have just stayed where you were. Maybe owners should make up post-it's stating date, & poor charge rate. That way, if you only get 25kW's - you could move over to a unit less crappy that deliveres 50kW. If & when repair folk show up to take care of problems, they could remove the post it.
.

 

[DarkMatter]

That makes perfect sense and yes, when I went out to take the plug off, it nearly burned my hand. It would have if I didn't get my hand off of it right away. Interesting thing is that this supercharging station is new, built within the last year.

Thank you for the information.

Also it could be a problem with the inlet on your car, or you could be not quite seating the connector all the way and getting a slightly poor connection. If the connector is very hot that is likely the cause for low charge rates, but the root cause could be several things.

 

[ecobon]

I would think that charge rate would be determined by the internal resistance that the pack might have rather than a simple count of the number of DCFC unless Tesla has determined that the correlation between DCFC and IR is strong enough to use to lower charge rates.

Again, we know that slow charging the packs is best for our cars, but supercharging and chademo is very convenient at times so this knowledge should help us understand and change our habits if we want longevity. There was that entire story about supercharging not harming our packs, but that statement did not include those that used DCFC (and supercharging) for their daily charging needs as it was assumed that these cars would be normally charged at home/office between 6-20kW.

Lastly, how long do you need these packs to last? The utility that they serve you (personally) with the way you use them is far more important that gaining a few minutes or seconds in charge times. I say keep using them as you see fit, and they buy another one when the time comes. It's just a machine and its consumable parts that is supposed to make your life more comfortable. I don't think too hard about how I use my Roomba to keep my floors clean and have gone through a couple of batteries.

2013 Model S 60 - 120K miles, 34MW 260-280 kW/mi with latest firmware updates. Supercharges at 103kW under 10% charge, and gradually lowers its charge rate. Takes about one hour from 10% to 90%. 90% battery yields 175-177 miles. Almost all charges were at a supercharger or chademo. Very rarely charged on AC at 240V; less than 50 times. ** Although the battery pack seems to be performing well with very little loss in range and charging rate, I expect this to "fall off of the cliff" at some point in the near future and I hope to use a salvaged 85 pack at that time.

2015 Model S 85D - 35K miles 12MW 300-310 kW/mi with latest firmware updates. Supercharges at 120kW under 10% charge, and gradually lowers its charge rate. Most charges have been done at home at 10kW. Maybe 90% at home, and 10% on road trips via supercharger. 90% battery yields 243-245 miles.

 

[sorka]

I would think that charge rate would be determined by the internal resistance that the pack might have rather than a simple count of the number of DCFC unless Tesla has determined that the correlation between DCFC and IR is strong enough to use to lower charge rates.

If the cooling system is working properly, it's like that supercharging actually causes less degradation over time compared to charging the same number of kw with say an 80 amp wall charger:

Does Repeated Supercharging Shorten Life of Battery Even at 90%?