With a mere 5% battery degradation, could it be possible that the buffer is released over time?

[Reciprocity]

This is bad advice, you shouldn't "expect" xx miles of range below 0%. While you may have 10 miles today, on a cold day or any other day those 10 miles may not be there. The "empty" light is the yellow and red warning indicators before you hit 0%.

The amount of available energy will fluctuate based on temperature, resistance of the pack, voltage, etc and the BMS is trying it's best to estimate how much is left across all modules. Even Bjorn's car stopped with 12? km of range left and had to be towed a few kilometers to reach his supercharger destination.

I was not giving advice only, relating experience. I Don't know Bjorn. Is his car a Dec 2016 model x? The point of the post was that people expect it to have a reserve, period. They won't read this forum or track down Bjorn for advice.

 

[internalaudit]

I'm down about 10% so no, I don't buy the OP's hypothesis.

(May 2014 build, 42k miles, 168+ Supercharges.)

Maybe you have used up your buffers, lol.

 

[internalaudit]

If they slowly released the buffer wouldn't that be harder on the battery as you were allowed to use those parts of the battery thereby increasing degradation?

Well, that degradation may be evident well past the first eight years. The goal for Tesla is to present itself in the best possible light today because its stock price is doing great and it may need to raise more funding in the near future.

For example, say people report 5% battery degradation over 4 years and 10% over 8. Unknowingly, the buffers are actually just being shrunk to maintain as close to the original driving range as possible or at least make it look like Tesla hit the right formula for its battery chemistry when in fact it degrades like any other with a decent TMS. Stock goes through roof when competing BEVs show more accelerated degradation.

In 2022, we find out battery degradation is no longer linear but exponentially dropping supporting the idea the the buffer is slowly shrunk to keep battery capacity close to the original as long as possible until there is no more buffer left, at which time it degrades like the rest of the competition.

By then Tesla may be cash flow positive and who would condemn it for such resourcefulness? I'd applaud and exclaim Bravado!

 

[gregincal]

A fine fantasy, but IMO really unlikely. The much simpler and far more likely explanation is that the battery degradation over the first 5 years is 5-10% (mine is about 7-8% after 50K miles and almost 5 years). I don't see why that's so unbelievable.

 

[Evoforce]

A fine fantasy, but IMO really unlikely. The much simpler and far more likely explanation is that the battery degradation over the first 5 years is 5-10% (mine is about 7-8% after 50K miles and almost 5 years). I don't see why that's so unbelievable.

Because they have been hearing about the Nissan Leaf battery and it has been giving all electric cars bad expectations.

 

[SSedan]

So for the buffer to be capable of what you propose it would have to be quite large.

Are you proposing it starts at like 15% so it can Dole out 2% or something per year? Sounds a bit far fetched when though of that way doesn't it?

 

[Reciprocity]

So for the buffer to be capable of what you propose it would have to be quite large.

Are you proposing it starts at like 15% so it can Dole out 2% or something per year? Sounds a bit far fetched when though of that way doesn't it?

No, because Tesla guarantees the battery for 8 years. It's called self preservation for Tesla to protect the battery. The bigger the buffer the longer the pack can function at a high level. Maybe they just won't release the extra, ever. It would allow the maximum life for the pack. Tesla has been talking about a million mile drive train, you just can't realistically do that if you let people charge to 100% everyday.

 

[dgpcolorado]

... Tesla has been talking about a million mile drive train, you just can't realistically do that if you let people charge to 100% everyday.

??? Tesla doesn't "let" people charge to 100% everyday. The charge level slider tries to limit to 50-90%. If you override that and charge higher for several days you will get a screen warning not to do that. Tesla knows how high you charge and can view those records remotely. Leaving the car at 100% can be considered abuse and a violation of warranty.

 

[Reciprocity]

??? Tesla doesn't "let" people charge to 100% everyday. The charge level slider tries to limit to 50-90%. If you override that and charge higher for several days you will get a screen warning not to do that. Tesla knows how high you charge and can view those records remotely. Leaving the car at 100% can be considered abuse and a violation of warranty.

I disagree.. Telsa guarantees the battery and never once tells you not to charge it to 100% every day. Tesloop does this 2x per day and has had their pack replaced for free when it died. I bet Tesla has learned from that and they will software lock a bigger battery. It has two benefits, it protects the longevity of the pack and the pack will appear to charge faster because it slows down to a trickle as it it gets closer to 100%. If its locked at 85-90%, the battery would have a much better chance of making it to 1 million miles with most of its usable range still remaining and would appear to charge faster up to the rated range as it would not drop to <5KW as it gets over 95%.

 

[gregincal]

I disagree.. Telsa guarantees the battery and never once tells you not to charge it to 100% every day. Tesloop does this 2x per day and has had their pack replaced for free when it died. I bet Tesla has learned from that and they will software lock a bigger battery. It has two benefits, it protects the longevity of the pack and the pack will appear to charge faster because it slows down to a trickle as it it gets closer to 100%. If its locked at 85-90%, the battery would have a much better chance of making it to 1 million miles with most of its usable range still remaining and would appear to charge faster up to the rated range as it would not drop to <5KW as it gets over 95%.

Tesla does guarantee the battery against degradation.

 

[cronosx]

The battery didn't died for 100% charge, the point is not that you charge 100% but if you stay idle at 100%, a thing that teslaloop probably doesn't do, since they use theyr car all the time or near enought

 

[Reciprocity]

Tesla does guarantee the battery against degradation.

No one said they did. They do have a reputation though, and they cannot have stories of massive battery degradation. So they do guarantee it in a way, by guaranteeing they have the best batteries and that goes to their reputation and value of their products.

 

[Reciprocity]

The battery didn't died for 100% charge, the point is not that you charge 100% but if you stay idle at 100%, a thing that teslaloop probably doesn't do, since they use theyr car all the time or near enought

How do you educate a million model 3 owners on that, who regularly fill their tanks?

 

[Doug_G]

No, they aren't doing any weird shenanigans to get the degradation rates. Lots of data has been collected on this, and the conclusion is that Tesla pampers their battery packs and achieves the expected potential of the cells. For more info see

Battery Survey « Plug In America

 

[internalaudit]

^ That survey doesn't put the hypothesis in hot water though. Just because there's little degradation, it doesn't prove there's no trickery involved.

Can Tesla / Panasonic battery packs be reversed re-engineered?

It's almost like VW with dieselgate where all other German competitors are wondering why VW vehicles didn't need ammonia.

 

[shokunin]

I was not giving advice only, relating experience. I Don't know Bjorn. Is his car a Dec 2016 model x? The point of the post was that people expect it to have a reserve, period. They won't read this forum or track down Bjorn for advice.

If people expect a "reserve" capacity below 0% then they need a crash course on EV's. It's no different than my laptop saying, I have 2% left and to plug in before the system shuts down. Don't expect the laptop to last another 5 minutes beyond 0%.

Any miles below 0% is simply due to the BMS not knowing what the true floor of the pack's voltage. Once it starts to learn the bottom floor those miles are likely to not be there the next time since the BMS has learned the bottom floor.

 

[gregincal]

How do you educate a million model 3 owners on that, who regularly fill their tanks?

By defaulting to 90% and popping a warning on the screen when you go to 100% perhaps?

 

[shokunin]

Perhaps Tesla slowly releases the capacity buffer say from 20% down to 15 then to 10%?

What buffer are we talking about here? Is this for software locked packs?

Other than the 4-5% bottom anti-bricking reserve to protect the cells from over discharging, only the software locked packs have a buffer that I can tell.

We have a 60kwh that is software locked to 40kwh and we can only charge to something like 68-69%, our charge slider doesn't go to 100% like the newer software locked versions (which is the same charge level technically). When the pack degrades it's not readily noticeable since the capacity is lost at the top end (from 100% to 95%).

However, we still see range fluctuations from 133-138 miles of range at max charge.

 

[Reciprocity]

If people expect a "reserve" capacity below 0% then they need a crash course on EV's. It's no different than my laptop saying, I have 2% left and to plug in before the system shuts down. Don't expect the laptop to last another 5 minutes beyond 0%.

Any miles below 0% is simply due to the BMS not knowing what the true floor of the pack's voltage. Once it starts to learn the bottom floor those miles are likely to not be there the next time since the BMS has learned the bottom floor.

Tesla is making a product where you dont have to have a crash coarse to use it. Its part of the long term solution vs ICE. Tesla's competitive edge is the batteries and bms system that allows them to make life easier for end consumers moving over from ICE. Tesla cant have batteries degrade significantly in the first 5 years, so they must go to extremes or risk a major backlash in the market. No crash coarse is going to save someone from being pissed that they have lost 20% or more range in 5-6-7 years. As EVs mature and appeal to a bigger segment of the community, Tesla cant have a rash of model 3s on flatbeds and all the bad press that goes with it. People are not as smart as you give them credit for and they will not read the manual. There is in fact a reserve below 0 of 10 miles at a minimum today on my Model X, I know because I have seen it personally twice. This does not include the anti brick portion which is completely unusable to save the battery from being bricked. The EPA ran the model 3 below 0 and had a total range of 340+ in their testing and Tesla is only claiming 310. You know the model 3 LR not the Model 3-75. That has to tell you something? It tells me that this is the future of how things are going to work. No one else even has a 300 mile car, even if they did their batteries would degrade faster because they would be completely unlocked, or they will have buffers as well to extend the life of the battery to be more inline with consumers expectations. These batteries flat out will not last 10 years without going to extremes. Maybe new chemistries will extend that in the future, but we are not there yet. You sacrifice something to get the high energy densities that Tesla has, either charge rates or recharge cycles with minimal degradation. An example is the storage batteries which must cycle every day for 10 years, but weight and bulk is not an issue so they use a different chemistry to maximize the durability over a long period of time.

 

[internalaudit]

What buffer are we talking about here? Is this for software locked packs?

Other than the 4-5% bottom anti-bricking reserve to protect the cells from over discharging, only the software locked packs have a buffer that I can tell.

We have a 60kwh that is software locked to 40kwh and we can only charge to something like 68-69%, our charge slider doesn't go to 100% like the newer software locked versions (which is the same charge level technically). When the pack degrades it's not readily noticeable since the capacity is lost at the top end (from 100% to 95%).

However, we still see range fluctuations from 133-138 miles of range at max charge.

Thanks for sharing some helpful information.

I am not well versed in industry terminology and I must have been referring to the combination of anti-bricking reserve as well as the buffer from the software locked packs, but for the M3, the latter is nonexistent.

So maybe like the Germans who'd like to underrate the HP and Torque of their engines, maybe Tesla is actually putting in more buffer that it could be reporting. Your situation is not a very good example because like you said, you have a lot of buffer apart from that anti-bricking reserve. If we take the base 55 kWh M3 that hasn't come out yet. Maybe Tesla actually put in a 57 or 58 kWh pack and boosted the reserve from what we thought was 5% to 10%. This way degradation (in terms of miles driven) will not be evident because of the increased buffer that was understated.

I respect Tesla but am just wondering how they can make battery so right whereas with Nissan, you know what happened for the earlier Leaf's.