If you fast charge, Tesla will permanently throttle charging

[stopcrazypp]

The old limits were

Some can charge at 90 KW (85 KWh A battery pack, near 1.06C charge rate)
some can charge at 105 KW (60 KWh with older battery pack, 1.75C charge rate)
some can charge at 111 KW (60 KWh with newer battery pack, 1.85C charge rate)
some can charge at 120 KW (85 KWh B or D battery pack, near 1.41C charge rate)

I can't imagine they'd have to lower it down to 0.8 C rate.

Newer cars (90 kWh and 100 kWh) don't hit any higher peak rate so the C rate relative to capacity is lower. Assuming 120 KW max its

some can charge at 120 KW (90 KWh pack, 1.33C charge rate)
some can charge at 120 KW (100 KWh pack, 1.2C charge rate)

which is already toning it down nicely. Maybe they pushed it too far with the old 60 kWh pack. Maybe 1.5C is the line they should have crossed?

The OP's car has a 90kWh pack, and others with 60kWh or software limited 75kWh don't seem affected, so I don't think general C-rate is the issue. The 90kWh pack however is the first one to switch to partial silicon anodes, but presumably the new 75kWh and 100kWh packs use the same chemistry, so not sure if this points to anything (unless Tesla switched).

 

[Naonak]

Here is the actual RO. I hope I've redacted all the proper information. As I said, I'll be happy to send the unredacted version to a mod or trusted individual for verification if required.

Page 3 is the relevant page, I am including the other two to have the complete report.

 

[S4WRXTTCS]

It's not exactly informing the customer if it's on some Tesla's technical blog, and not their consumer facing blog.

To me this is the part that has me irked. That once again Tesla isn't informing people what they need to know.

Like lets say you're shopping for used Tesla. Having this information would be absolutely critical to your purchase.

 

[Cyclone]

My suspicion is that the counter only started with a software change not that long ago (maybe a year) which means that most high milage drivers have most of their early driving not count.
You, however, seem to have a newer car also so perhaps that theory is off.
I don't think many people dc charge more than once per day and not many of them would notice a slightly slower charging rate.

I actually think it may be the other way around (if this isn't some misinformation from Tesla to Op). The Teslaloop people I believe (or another very high mileage user) reported that the car misreported energy available after 200k miles. The theory was that was a stake in the ground and Tesla switched to a different algorithm at that mileage because they had too little data to satisfy their testing of the regular algorithm. At that point, the car's battery was swapped since software engineering hadn't yet done that modeling and refined the algorithm.

Thus, this could be some really high number Tesla codes in that they did not think anyone could reasonably reach before they have the data to do their analysis. The Op then using DC charging almost exclusively made him an outlier that push him past that limit. Again, this could have been a stake in the ground number and doesn't yet account that lower charge rates CHAdeMO gives and Tesla simply felt they would get the data from the test fleet before any customer ever got to the limit.

 

[Naonak]

@Naonak Nope. If you read the details on the battery warranty it doesn't cover degradation at all. So if Tesla is doing this at all, and they are doing it to prevent degradation, not failure, they are doing it to make sure you keep your battery capacity as long as possible. (So it is good for you and worse for them since you would be at Superchargers longer.)

And in reality how much charging did you get between 120kW and 90kW before? (How quickly did it taper down to 90kW?) How much longer per charge does it take you now? (Not even a second longer where you do most of your charging at CHAdeMO chargers.)

I haven't read the whole battery warranty - it was my understanding that if the battery degrades more than 6% I believe (or maybe it was 7%), then it is considered degraded and will be replaced/refurbished. Regardless, though, there is no other reason for them to do this other than to prevent having to honor the battery warranty in greater numbers than they would otherwise.

If that were not the case, they'd let people degrade their batteries so they could sell them new ones after denying the warranty claim due to whatever reason they deem feasible. To the best of my knowledge, there is a degradation threshold on the battery that will be covered by warranty.

As far as how much charging I got between 120kW and 90kW, I will have to do a tally on that and that will take time, but I too want to know the answer to that. However, it doesn't change the fact that Tesla has literally broken my vehicle intentionally and without my consent and refuses to fix it.

 

[roblab]

Well, really, I tried to read all these threads, but this was a common discussion when I first got my Sig S. Everyone was talking about battery degradation, everybody knew it would degrade, everybody was aware that heat degraded batteries, and that supercharging built up more heat. That was four and a half years ago, and we now have a WHOLE bunch of new people who don't understand that and are mad because Tesla never did spell it out but they still program the battery to cut charging rate back as resistance and age increase.

Supercharging increases degradation. There. I've said it, and I know nothing. And it's Tesla's fault. And my car now takes four whole minutes longer to charge than it did before! Maybe I should sue. Maybe I should have bought a Toyota hybrid.

Oh, well.

 

[No2DinosaurFuel]

If true, this is another tactic tesla is using to minimize the battery warranty. Like other have said. Tesla needs to own up on what they promise.

Well, really, I tried to read all these threads, but this was a common discussion when I first got my Sig S. Everyone was talking about battery degradation, everybody knew it would degrade, everybody was aware that heat degraded batteries, and that supercharging built up more heat. That was four and a half years ago, and we now have a WHOLE bunch of new people who don't understand that and are mad because Tesla never did spell it out but they still program the battery to cut charging rate back as resistance and age increase.

Supercharging increases degradation. There. I've said it, and I know nothing. And it's Tesla's fault. And my car now takes four whole minutes longer to charge than it did before! Maybe I should sue. Maybe I should have bought a Toyota hybrid.

Oh, well.

There is some evidence that supercharging actually reduces battery degradation. It has to do with the time the battery is heated. During supercharging the battery is heated up for a shorter period of time.

 

[xyeahtony]

Am i missing something? My supercharger rates are usually between 75-90Kwh and i thought that was normal. it'll start off like 110ish but taper down over the course of several minutes.

 

[stopcrazypp]

I haven't read the whole battery warranty - it was my understanding that if the battery degrades more than 6% I believe (or maybe it was 7%), then it is considered degraded and will be replaced/refurbished. Regardless, though, there is no other reason for them to do this other than to prevent having to honor the battery warranty in greater numbers than they would otherwise.

If that were not the case, they'd let people degrade their batteries so they could sell them new ones after denying the warranty claim due to whatever reason they deem feasible. To the best of my knowledge, there is a degradation threshold on the battery that will be covered by warranty.

As far as how much charging I got between 120kW and 90kW, I will have to do a tally on that and that will take time, but I too want to know the answer to that. However, it doesn't change the fact that Tesla has literally broken my vehicle intentionally and without my consent and refuses to fix it.

This is wrong. The battery warranty in fact explicitly excludes degradation (see page 5):
"The Battery, like all lithium-ion batteries, will experience gradual energy or power loss with time and use. Loss of Battery energy or power over time or due to or resulting from Battery usage, is NOT covered under this Battery and Drive Unit Limited Warranty. See your owner documentation for important information on how to maximize the life and capacity of the Battery."
https://www.tesla.com/sites/default/files/pdfs/Model_S_New_Vehicle_Limited_Warranty_201602_en_NA.pdf

 

[Canuck]

I'm honestly speechless at this.

Seems a little over the top to me.

I haven't read the whole battery warranty - it was my understanding that if the battery degrades more than 6% I believe (or maybe it was 7%), then it is considered degraded and will be replaced/refurbished.

ha... 7% degradation over 8 years is not bad!

The warranty does not discuss degredation percentages. It reads:

"The Battery, like all lithium-ion batteries, will experience gradual energy or power loss with time and use. Loss of Battery energy or power over time or due to or resulting from Battery usage, is NOT covered under this Battery Limited Warranty. See your owner documentation for important information on how to maximize the life and capacity of the Battery."

What is that percentage? The best guess (with hearsay evidence of Tesla) is more than 30%. For the Leaf, it's four lost bars out of 12. The first lost bar is ~15%, and every bar after that is ~7.5%, so they require 37.5% loss before warranty replacement.

Regardless, though, there is no other reason for them to do this other than to prevent having to honor the battery warranty in greater numbers than they would otherwise.

You have about 250 fast charges (I don't think the car's stats distinguish between SC and Chademo - so it's 250 SC - wow!) plus no AC charging.

So here's your "no other reason" for me:

You've been throttled back. This also explains why you and not others.

If that were not the case, they'd let people degrade their batteries so they could sell them new ones after denying the warranty claim due to whatever reason they deem feasible.

Read over at the Leaf forums and you can find many ways people have done this to get a new battery under warranty because they are so close to dropping that fourth bar yet so close to miles/date warranty expires. Most involve a lot of heat with repeated charging and holding hot 100% charges. Tesla makes that very hard to do, and no one needs to either, since good luck getting even close to 30% degradation when the battery warranty comes up. So you lost me at this one too.

 

[sdorn]

This is wrong. The battery warranty in fact explicitly excludes degradation (see page 5):
"The Battery, like all lithium-ion batteries, will experience gradual energy or power loss with time and use. Loss of Battery energy or power over time or due to or resulting from Battery usage, is NOT covered under this Battery and Drive Unit Limited Warranty. See your owner documentation for important information on how to maximize the life and capacity of the Battery."
https://www.tesla.com/sites/default/files/pdfs/Model_S_New_Vehicle_Limited_Warranty_201602_en_NA.pdf

My reading of the warranty language is that if the degradation is gradual and due to battery usage, then it is not covered. However, if there is excessive degradation above what would be considered normal loss due to battery usage, that would be covered as a malfunctioning or defective battery.

I read some old posts from forums made back in 2013 and 2014, and it sounded like a few people were told by Tesla back then that degradation below 70% of the original capacity within the 8 year warranty period would constitute a malfunction or defective battery that would be replaced under warranty.

 

[Electroman]

I think Tesla should simply remove the battery degradation protection algorithm for OP and then say, 'good luck. You are on your own now on battery degradation'.

You see OP didn't know that battery degradation is not covered. That ignorance is not Teslas fault.

To lose sleep over 5 extra minutes on an SC charging is silly.

To continually only charge through high rate DCFC - 250 in one year - is not normal use case either. OPs case is an outlier.

 

[JRP3]

Supercharging increases degradation.

Yet oddly the studies which have tracked pack capacity and charging types have shown cars which have done the most supercharging to have the least capacity degradation.

 

[dhanson865]

For the Leaf, it's four lost bars out of 12. The first lost bar is ~15%, and every bar after that is ~7.5%, so they require 37.5% loss before warranty replacement.

Not so. As seen in slightly different form at Battery - Electric Vehicle Wiki

I've modified it to show top and bottom of each bar and the capacity of each full bar for hopefully easier comprehension.

Leaf capacity bars
100% to 85% = 12 bars (15%)
85% to 78.75% = 11 bars (6.25%)
78.75% to 72.5% = 10 bars (6.25%)
72.5% to 66.25% = 9 bars (6.25%)
66.25% to 60% = 8 bars (6.25%)
60% to 53.75% = 7 bars (6.25%)
53.75% to 47.5% = 6 bars (6.25%)
47.5% to 41.25% = 5 bars (6.25%)
41.25% to 35% = 4 bars (6.25%)
35% to 28.75% = 3 bars (6.25%)
28.75% to 22.5% = 2 bars (6.25%)
22.5% to 16.25% = 1 bar (6.25%)
16.25% = 0th bar (16.25%)

4 bars lost is 66.25% remaining aka 33.75% lost.

and essentially any bar other than the 12th and the lack of bars aka 0th is 1/16th of the pack capacity aka 6.25%.

 

[oktane]

Battery degradation is NOT covered under warranty?

So if my battery loses 50% capacity tomorrow, but doesn't "fail", I'm screwed?

That doesn't sound right. There should be published capacity limits (like for the Leaf above) that differentiate "normal wear and tear" from a dud battery prematurely degrading.

 

[dhanson865]

Battery degradation is NOT covered under warranty?

So if my battery fails tomorrow, I'm screwed?

That can't be right.....

fail does not equal degradation. Degradation is reduction of capacity but still usable. Fail is you can't drive the car.

Basically if your range drops by 1% you have no recourse. If your car won't drive across a parking lot you get a replacement pack.

What happens in between those extremes is varies and you can argue where the dividing line should be.

edit: as was I (editing while you quoted me)

as to 50% lost quickly I'd assume max voltage or resistance would be off and you'd get a new pack because performance was out of spec in that drastic a case. Even a 10% loss in one day would be drastic.

Daily losses should be near to a rounding error, monthly should be a trend but still allow for summer vs winter seasonal effects. Yearly should even out those effects enough to be in the correct realm for degradation. Even then 50% in a year would be catastrophic failure of some sort.

 

[oktane]

fail does not equal degradation. Degradation is reduction of capacity but still usable. Fail is you can't drive the car.

Basically if your range drops by 1% you have no recourse. If your car won't drive across a parking lot you get a replacement pack.

Ha, you're too quick I was editing my post when you replied and quoted me!

 

[Electroman]

Battery degradation is NOT covered under warranty?

So if my battery loses 50% capacity tomorrow, but doesn't "fail", I'm screwed?

That doesn't sound right. There should be published capacity limits (like for the Leaf above) that differentiate "normal wear and tear" from a dud battery prematurely degrading.

You are screwed buddy. Look at how many ways Tesla screwed you - AP and now battery degradation. It is 'I am going to sue you' time.

 

[Canuck]

Not so... 4 bars lost is 66.25% remaining aka 33.75% lost

The original post said replacement at 7%. I said more like 30% and then I used Nissan as an example and I used "~" ("approx") to arrive at 37.5%. I'm off by 3.75%. That's approximately to me!

There should be published capacity limits (like for the Leaf above) that differentiate "normal wear and tear" from a dud battery prematurely degrading.

You're using the Leaf as an example of having clear guidelines for battery replacement when it only came about after a class action lawsuit was certified?

 

[oktane]

You are screwed buddy. Look at how many ways Tesla screwed you - AP and now battery degradation. It is 'I am going to sue you' time.

Tesla doesn't need me to sue them, they already have a couple nice lawsuits pending, which they will lose. They will hasten their own demise if they keep up this attitude. You can go down with them if you chose!