If you fast charge, Tesla will permanently throttle charging

[JonMc]

Hi Everyone -

The peak charging rate possible in a lithium-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.

Thanks,

Jon

 

[byeLT4]

Hmmmm.....

 

[thegruf]

...And as I said multiple times already, if he had not pursued this perverse charging strategy over the past year he would not have any throttling at all...

Some of your comment I agree with, most honestly I don't.

Saying the OP pursued a "perverse charging strategy" is a personal attack and out of order imo.

He appears to have used the car in an entirely reasonable manner entirely within the capability of the car, with no suggestion from Tesla in advance that such a strategy might negatively impact on his charging rates in future.

 

[thegruf]

@JonMc

just for additional clarity can you confirm if there is any difference between Supercharging and Chademo charging in this respect.

 

[ODE90D]

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.

I am very interested in hearing more about the statistics. Could the 1% really mean practically every Tesla with the new battery chemistry introduced in 90D? Not many of those are old enough to have a high SuC usage - but they will eventually. I have yet to see a 90 kWh battery with +50k miles charging with a peak above 100 kW.

 

[Cloxxki]

Would be interesting to know why some 85's seem to be getting fast charging, possible at very significant capacity losses. Might those be top end cutoffs of sorts? Or huge heat losses making for effectively reduced charging rates anyway?

 

[Kant.Ing]

For cars with high mileage but without experiencing any SC throttling, is it still 100% safe to charge the battery?

 

[bro1999]

Hi Everyone -

The peak charging rate possible in a lithium-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.

Thanks,

Jon

So basically, that was a long way of saying "Yes, throttling occurs".

 

[n2mb_racing]

Hi Everyone -

The peak charging rate possible in a lithium-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.

Thanks,

Jon

Why does chademo count as fast charging? It's below 0.8C.

 

[Panu]

when the conditions of the cell change gradually with age and usage

Thank you for the information. Can you please confirm that there is no counter that would for example count how many times you have DC charged and the charging rate restriction is based solely on battery cell condition analysis?

 

[sillydriver]

Hi Everyone -

The peak charging rate possible in a lithium-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.

Thanks,

Jon

While the company's giving us information reactively (to a discussion thread) is not as desirable as giving it proactively, I'm glad Tesla made a comment and (for my part) thank them for it.

The two things I'm struck by are, first, the couple mentions of safety in the comment above. If throttling reduces the (very small) probability of the car bursting into flames while charging, then they've got to do it.

The second is their putting age and usage in the context of the two other factors that result in a slower-than-maximum rate of charge: temperature and SOC. I suppose you can argue that since we all accept they don't need to proactively warn us that charging slows in the cold, and slows as the battery gets full, they have an excuse for not warning us that it slows after prior high-current charging.

Nevertheless, if Tesla did warn it's customers proactively about stuff that will lead to 560-post complaint threads (and it should be obvious to them what kind of stuff that would be) then both they and everyone else would be better off.

 

[AnxietyRanger]

Thank you for the input.

OK, so basically @Naonak and others reported this phenomenon correctly. And also @Canuck 's theory was incorrect. If this information from @JonMc is correct.

What remains unclear is whether or not there is a counter that triggers the permanent throttling, as well as how those 1% of affected Tesla customers end up being "selected" for throttling. We also do not know when this change was introduced, was it perhaps a quiet part of 8.0 the software update like the Ludicrous throttling counters were, or has it always been this way.

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

Here is what the service report said @Panu, just as a reference. The vehicle had been DC charged an approximated 300 times (250 CHAdeMO + 50 SpC), if the info is correct.

Service report and other links through here: If you fast charge, Tesla will permanently throttle charging #541

 

[Panu]

There are 18kW Chademo chargers in Finland which I've been using and I would not be very happy if these charging sessions (sometimes 1 minute to test the charger) have incremented the counter in my car.

 

[Matias]

There are 18kW Chademo chargers in Finland which I've been using and I would not be very happy if these charging sessions (sometimes 1 minute to test the charger) have incremented the counter in my car.

What about using my dual chargers to get 22 kW?

 

[AnxietyRanger]

There are 18kW Chademo chargers in Finland which I've been using and I would not be very happy if these charging sessions (sometimes 1 minute to test the charger) have incremented the counter in my car.

Unless we are told otherwise, so far the data we have would suggest they having been counted to some extent. Right? The report from the SC and @JonMc being vague about what actually happens. Whether or not they have been counted as "1 charge time" (bad) or "1 minute of charge" (better) or "1 kWh of charge" (best?), is completely unknown...

However, we do not know whether or not this applies to only certain battery pack revisions, for example. And I agree, this is a speculative point at this time, and a clarification of what is counted and what the threshold, if there are threshold(s), is/are would be welcome.

What about using my dual chargers to get 22 kW?

From the data so far I would expect they are not counted as DC charges.

But I guess that is as far as speculation takes us, more input and data is welcome.

 

[n2mb_racing]

What about using my dual chargers to get 22 kW?

Presumably no, but that's the problem with not knowing or having to guess the logic. Chademo at 18 kW might trigger it, but 22 kW AC charging likely does not?

 

[AnxietyRanger]

The problem with only 1% of customers experiencing this is that without more information, 100% of DC charging customers fear they are next.

 

[Matias]

Presumably no, but that's the problem with not knowing or having to guess the logic. Chademo at 18 kW might trigger it, but 22 kW AC charging likely does not?

My point was, that calculation of 18 KW chademo (if they are calculated) is very stupid, because with dualchargers, you get more than that.

 

[n2mb_racing]

My point was, that calculation of 18 KW chademo (if they are calculated) is very stupid, because with dualchargers, you get more than that.

Agreed!

 

[AnxietyRanger]

I have found that people really dislike counters that result in permanent, definitive downgrades. People are naturally wary of all kinds of penalties. Their natural reaction to them may well be disproportionate to the harm.

Gradual wear and tear is one thing, but this is an obvious cost to using DC charging, not gradual aging. At some point, unknown, using DC charging means you may pay this price for it for the life of that car.

We shall see how that goes down with people. The psychology of it seems troublesome. Were this an ICE, I would expect there to be a maintenance regime for something like this.