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Tesla Model S battery degradation data

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Re: Tesla Model S battery degradation data

#111

Post by mythmon_ »

GuB-42 wrote: post #102

That's quite impressive. What I am wondering is why they do do well, barely losing 10% in 5 years, compared to phone or laptop batteries that last maybe 3 years on average. AFAIK, they use the same technology, in fact, I wouldn't be surprised if the same batch of cells end up partly in Teslas and partly in laptops.

I'd imagine it is down to the number of recharge cycles. A phone tends to go through an entire recharge cycle every day to two, whereas I'd imagine a Tesla wouldn't go through it's entire range as often.

Re: Tesla Model S battery degradation data

#112

Post by wongarsu »

JshWright wrote: post #54
dom0 wrote: post #46

Earlier quoted context omitted.

> human-centric temperature scale One point (100 °F ~ 37 °C) doesn't make a scale.

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.

Re: Tesla Model S battery degradation data

#113

Post by stephengillie »

wongarsu wrote: post #101
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…

>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.]

Re: Tesla Model S battery degradation data

#114

Post by hwillis »

GuB-42 wrote: post #102

That's quite impressive. What I am wondering is why they do do well, barely losing 10% in 5 years, compared to phone or laptop batteries that last maybe 3 years on average. AFAIK, they use the same technology, in fact, I wouldn't be surprised if the same batch of cells end up partly in Teslas and partly in laptops.

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 average American's daily driving distance is ~30 miles or 10-15% of the battery capacity. Phones are often almost totally discharged every day. Tesla's are also typically only charged to 80%, although you can turn that off.

4: Teslas have a low average power use: 300-600 horsepower on tap but cruising on the highway uses very little. In technical terms their current rate is ~.2-.3 C, while phones can have much higher C rates.

5: Phones use an LCO chemistry, Teslas use NCA which is more stable over the long term. Tesla also has custom additive and cathode/anode materials that improve lifespan a great deal.

Phone and laptop batteries almost all come from china, Tesla batteries are korean. They're pretty premium as far as 18650s go so they're used in power tools and really good laptops. However Tesla has their own proprietary chemistry so nobody else gets to use their blend.

Re: Tesla Model S battery degradation data

#115

Post by hwillis »

mythmon_ wrote: post #111
GuB-42 wrote: post #102

That's quite impressive. What I am wondering is why they do do well, barely losing 10% in 5 years, compared to phone or laptop batteries that last maybe 3 years on average. AFAIK, they use the same technology, in fact, I wouldn't be surprised if the same batch of cells end up partly in Teslas and partly in laptops.

I'd imagine it is down to the number of recharge cycles. A phone tends to go through an entire recharge cycle every day to two, whereas I'd imagine a Tesla wouldn't go through it's entire range as often.

If you check the interpolated cycle life at the source, the oldest Teslas have gone through 30%.

Re: Tesla Model S battery degradation data

#116

Post by vvanders »

dmitrygr wrote: post #44
vvanders wrote: post #36

Earlier quoted context omitted.

Sure, but you lead with: > not because of amount of use, but because of time Which makes it seem like time is more important that heat.

heat != use think of it more as BADNESS = integral(abs(temp - 5), over time) * integral(abs(charge_amt - 40%), over time)

heat = (discharge + charge)

use = (discharge + charge)

hence: heat = use ;)

Re: Tesla Model S battery degradation data

#117

Post by incompatible »

sowbug wrote: post #107
redthrowaway wrote: post #64

>Want to buy a Tesla? Use my referral link! Man, this only needs to work once for it to easily outstrip all other forms of revenue a blog might generate.

The current referral program offers only non-monetary awards (toy car, fancy wheels, entry in contest to win car). Better than a poke in the eye, but not as good as cash.

There's not much point in Tesla offering a lot. A search for "Tesla" in Google gets you to the right place to buy one with a couple of clicks.

Re: Tesla Model S battery degradation data

#118

Post by ridgeguy »

sqeaky wrote: post #10
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…

I have seen plenty of cars not make to 165_000 miles, those that do are often near the end of their life. Mine is beat and barely holding together and it is at 97_000 miles.

My automotive longevity anecdata:

'99 Toyota 4Runner, 232K miles (currently own); '85 Honda Civic, 197K miles; '59 VW bus, ~490K miles (with a rebuild of the 40hp engine at ~240K miles and a transaxle from a junker at ~300K miles).

Re: Tesla Model S battery degradation data

#119

Post by digikata »

hwillis wrote: post #114
GuB-42 wrote: post #102

That's quite impressive. What I am wondering is why they do do well, barely losing 10% in 5 years, compared to phone or laptop batteries that last maybe 3 years on average. AFAIK, they use the same technology, in fact, I wouldn't be surprised if the same batch of cells end up partly in Teslas and partly in laptops.

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.

Re: Tesla Model S battery degradation data

#120

Post by perryh2 »

hwillis wrote: post #114
GuB-42 wrote: post #102

That's quite impressive. What I am wondering is why they do do well, barely losing 10% in 5 years, compared to phone or laptop batteries that last maybe 3 years on average. AFAIK, they use the same technology, in fact, I wouldn't be surprised if the same batch of cells end up partly in Teslas and partly in laptops.

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…

Tesla uses batteries from Panasonic (Japanese) [0].

[0] https://electrek.co/2016/11/02/tesla-panasonic-2170-battery-...

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