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Tesla Model S battery degradation data

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Re: Tesla Model S battery degradation data

#121

Post by aidenn0 »

TomMarius wrote: post #7

Average life of ICE vehicles can't be 266kkm, that's absurdly low. Most of people I know have bought vehicles with that mileage and used it for another 100kkm after that at some point in their life (think first/second car, second family car, etc.). It's important to know that especially in Central/Eastern Europe, you can never trust the car's odometer - even the cars I'm talking about had probably more than 350kkm wh…

As a kid being driven around in carpools, and being one of the smaller kids in the neighborhood, I ended up in the middle-front seat a lot (Back when cars had bench seats in the front). I saw exactly one car with over 160 000 km (100k miles) and it was a manual transmission Volvo.

I don't know why my friends parents had lower mileage cars, but I know what it was with my mom:

At this point most cars were automatic, and they crammed lots of parts of the transmission into a hard-to-service single-part-number item. Three times while I was growing up (~32 000 km per year driving) she had the transmission fail at around 170 000km and the mechanic quoted her a number approximately equal to the street-value of the car to fix.

Re: Tesla Model S battery degradation data

#122

Post by sureshv »

wongarsu wrote: post #112
JshWright wrote: post #54

Earlier quoted context omitted.

Heh, sorry, that was just a tongue-in-cheek joke, not a central point of my comment. 0 to 100 on the Fahrenheit scale is "Really Cold" to "Really Hot". 0 to 100 on the Celsius scale is "Kinda Cold" to "Unsurvivable Hot". When I say it's "human-centric" I mean that it maps well to the range of human comfort (Celsius is obviously vastly superior in just about every other use).

I'm not so sure I would call 100° C "unsurvivable". People go in saunas with 100° C all the time for enjoyment. If the air is dry enough, it's not that hot. Maybe it's unsustainable, you can't survive that indefinitely. But you can't survive 0° F indefinitely either, unless we bring protective clothing into the game.

100C would send you to the burn unit. I think you mean 100F.

Edit: 100C is boiling point for water - is the ambient temp of the Sauna 100C?

Re: Tesla Model S battery degradation data

#123

Post by 11thEarlOfMar »

This is pretty surprising. What it means is that most owners will not need to replace their batteries in the time that they own the car. In my 'total cost of ownership' models, I've assumed a battery replacement at 100,000 miles, but that appears to not be necessary. This changes the calculation considerably. Not to mention that if the drive train can go 400,000 miles without needing major repair, I can keep the car 2x as long as an ICE, further reducing the cost of owning an electric vehicle.

Re: Tesla Model S battery degradation data

#124

Post by photojosh »

digikata wrote: post #119
hwillis wrote: post #114

Earlier quoted context omitted.

In order of importance: 1: Tesla cells are hard limited to a lower voltage, reportedly 4.1 V rather than the 4.2-4.4 V maximum. Phone batteries run much closer to their maximum voltage 2: Tesla cells stay at much lower temperatures and have active cooling. Phone batteries are used to sink heat from the processors and wifi. 3: Teslas have a much lower normal depth of discharge. In addition to the derated voltage, the…

A lot of these could be mitigated if phone makers were willing to put in a slightly larger capacity battery and apply more conservative max-min limits in their battery management system. But I guess companies are happy to keep sales up via planned obsolescence.

My phone rarely gets below 50%, and I'd say it only gets below 20% a handful of days a year.

But yes, I've often thought it would be nice to have a toggle to say "Prolong battery life (as in years)... I only want a 90% charge since I'm not going to be using much tomorrow."

I've wondered too whether I should only use a slow (1A) charger for the overnight charge rather than the full 2.4A. But then again, I only keep my phone for 2 years before passing on it, so I've not had to care that much.

Re: Tesla Model S battery degradation data

#125

Post by photojosh »

stephengillie wrote: post #113
wongarsu wrote: post #101

Earlier quoted context omitted.

>but there's not really any standardization of this as far as I know There is. Resolution 10 of the 22nd General Conference on Weight and Measures [1] (the body responsible for the SI system) forbids the use of comma ordot as thousands separator. Other institutions like NIST have followed suit, forbidding or at least recommending against it. The recommended approach is to use spaces as thousand separators (or ideally…

[Comments cannot be deleted once a reply has been made.]

I'm curious at to when that example would ever be suitable; memory sizes should be grouped in 3s as well.

The only one I can think of is phone numbers, e.g. Australia is a 4-3-3 grouping for mobiles. But a space has been the standard delimiter there anyway.

Re: Tesla Model S battery degradation data

#126

Post by photojosh »

microcolonel wrote: post #56
kbenson wrote: post #8

> The red fitted line has a slope above 60.000 km (say 40,000 miles) of 1% per 50.000 km (30,000 miles). I'm going to bring this up because I think it's both interesting, and sometimes it comes up on its own and detracts from the conversation with conjecture (and sometimes harsh assumptions) until covered adequately[1] - different countries have different conventions for whether they use a comma or period for a thous…

Frankly it might be a bit confusing to Canadians, here we use the U.S. numeric conventions, but we tend to use a mix of SI and imperial units, and in this case we'd use kilometres for ground distance, with thousands separated by commas. The UK also seems to prefer commas to separate thousands. I'm inoculated against confusion about this because I've done a lot of software and content localization, and have a grasp on…

> Why even talk about thousands of kilometres when you can speak in tens of megametres?

Probably because when you're speaking about them colloquially, you don't say "kilometres" you say "kays". That probably varies by locale too, I'm in en_AU. How is it over your way?

I do like the nerdiness in the idea of saying "two megs" instead of "two thousand kays", but it's never going to happen.

Re: Tesla Model S battery degradation data

#127

Post by wongarsu »

sureshv wrote: post #122
wongarsu wrote: post #112

Earlier quoted context omitted.

I'm not so sure I would call 100° C "unsurvivable". People go in saunas with 100° C all the time for enjoyment. If the air is dry enough, it's not that hot. Maybe it's unsustainable, you can't survive that indefinitely. But you can't survive 0° F indefinitely either, unless we bring protective clothing into the game.

100C would send you to the burn unit. I think you mean 100F. Edit: 100C is boiling point for water - is the ambient temp of the Sauna 100C?

I'm thinking of finnish-style saunas, which operate at 60 to 100 °C [1] (with 100°C being a frequent option). You usually stay in them 10-15 min at a time, but I guess if you keep hydrated you could stay a lot longer.

Finnish saunas are kept very dry. Sufficiently dry air makes very hot temperatures bearable because evaporation cooling from sweat gets more effective the dryer the surrounding air is. Water on the other hand makes sweating useless, which is why you can't tolerate water temperatures above body temperature (depending on how much of you is submerged).

1: https://en.wikipedia.org/wiki/Finnish_sauna#Types_of_sauna

Re: Tesla Model S battery degradation data

#128

Post by photojosh »

sureshv wrote: post #122
wongarsu wrote: post #112

Earlier quoted context omitted.

I'm not so sure I would call 100° C "unsurvivable". People go in saunas with 100° C all the time for enjoyment. If the air is dry enough, it's not that hot. Maybe it's unsustainable, you can't survive that indefinitely. But you can't survive 0° F indefinitely either, unless we bring protective clothing into the game.

100C would send you to the burn unit. I think you mean 100F. Edit: 100C is boiling point for water - is the ambient temp of the Sauna 100C?

"Air temperatures averaged around 75–100 °C (167–212 °F) but sometimes exceeded 110 °C (230 °F) in a traditional Finnish sauna." [0]

Apparently so! TIL.

[0] https://en.wikipedia.org/wiki/Sauna

Re: Tesla Model S battery degradation data

#129

Post by mikeash »

sapienthomo wrote: post #108
mikeash wrote: post #97

Earlier quoted context omitted.

I think people get confused because it's widely (and correctly) reported that Tesla uses 18650 cells. The confusion is that people think that's a model number, but it's actually just a size and shape. It's literally 18x65mm and the 0 means it's round. It tells you nothing at all about what's inside the cylinder.

NCR18650B is a specific series of parts from Panasonic(/Sanyo). If you want literally the exact battery that Tesla uses in the S, call Panasonic and tell them you want a shipment of ten million NCR18650BF (the new one with the silicon anode. The identity of these parts has been confirmed multiple times by people tearing down the battery packs (where they get this kind of disposable income, we don't know) and comparin…

Do you have links? All I'm turning up with search terms like "NCR18650BF tesla teardown" are people using that as the closest point of comparison or speculating.

Re: Tesla Model S battery degradation data

#130

Post by photojosh »

xanderstrike wrote: post #100
sqeaky wrote: post #40

Earlier quoted context omitted.

What percentage of car owners do this? There is some percentage of cars crashed in the first week. It only takes a few of these to cancel out the average of extreme outliers like your car. For reference I have never seen an odometer with more than 200 000 on it before. Even most classic rebuilds I have seen like 69 Corvettes have some high 100K count on them, some event have reset odometers.

Poke your head in any work van or truck and you'll see 200k and up.

Or any taxi. My trip back from the airport last week had 440k on a Prius.
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