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Tesla Model S battery degradation data

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Re: Tesla Model S battery degradation data

#131

Post by Coincoin »

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…

I'm always surprised that en_CA and fr_CA are so different. We use spaces as separator and comma for the decimal. Also we use the 24h format while the ROC uses 12h. We do use 12h colloquially though. Dates are officially y-M-d but most people use d/M/y.

It's funny how in Canada we have some specific remnants of the imperial system. Most people under 50 have no idea what a Fahrenheit is (myself included), except for pool water and oven temperature. Go figure.

Re: Tesla Model S battery degradation data

#132

Post by photojosh »

GuB-42 wrote: post #98
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've heard from mechanics that ICE cars are designed to last 250kkm reliably. It doesn't mean that car can't last longer than that, but more and more repairs are to be expected, and it is more likely to fail at any time. If you are a professional, keeping such a car doesn't make economical sense. Furthermore, in high income countries, they actually want you to destroy these old cars to promote the new car market.

I have family who regularly drive old bombs. (Do they call them that elsewhere?) They apparently spend half their life at the mechanic. (Slight exaggeration.) Yeah, I'm not doing that.

Re: Tesla Model S battery degradation data

#133

Post by deelowe »

sqeaky wrote: post #35
dmitrygr wrote: post #30

Earlier quoted context omitted.

They are rated in cycles so consumers do not need a degree in physics to understand the reality. Feel free to inspect a REAL spec sheet for a LiPo battery from a manufacturer (I think ATL provides some online)

Can you provide links? You clearly feel we have never seen a "real" sheet, perhaps more hand holding is order. I would appreciate the experience and would not do it without the link.

Here's a "real" manufacturer datasheet. The spec the battery life in cycles. Op may be correct, I don't know battery chemistry, but I've never seen batteries spec'ed the way the op describes in any "real" datasheets I've read.

http://www.omnitron.cz/download/datasheet/NCR-18650PF.pdf

Re: Tesla Model S battery degradation data

#134

Post by acchow »

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.

Tradeoff between weight, battery life, and battery lifetime.

I'm glad phone manufacturers heavily optimize for the first 2 and not the latter.

Re: Tesla Model S battery degradation data

#135

Post by elihu »

sorenjan wrote: post #33
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've never seen anyone put more than one kilo before the unit before.

I guess it's less confusing than using "mm" for "megameters". "I drove my car 266mm" doesn't sound like much of an accomplishment.

Re: Tesla Model S battery degradation data

#136

Post by Coincoin »

photojosh wrote: post #126
microcolonel wrote: post #56

Earlier quoted context omitted.

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.

>I do like the nerdiness in the idea of saying "two megs" instead of "two thousand kays"

But they are not the same!!oneoneone. Unless you are in the dog food prefixes camp. Are you?

Re: Tesla Model S battery degradation data

#137

Post by skykooler »

WillPostForFood wrote: post #82
dmitrygr wrote: post #9

This is fundamentally flawed because lithium batteries mostly degrade not because of amount of use, but because of time (and their charge state and temperature during this time). No matter if used or not, they will lose capacity. The rate of capacity loss is mainly dependent of average charge (best is 40%, worst is 100%) and temperature (best is 5 degrees C, the higher the worse). (This is also why phone batteries fa…

So if you were optimizing your phone for low battery degradation, when would you charge it, and to what %? If you were trying to keep it around 40%, would a good strategy be to let drop to 20%, and then only charge to 60%, or would you bias it even lower to keep it away from 100%, like a working range of 10-50%?

The ideal state of charge for a lithium battery is 50%. So charging between 20% and 80% would significantly lengthen battery life. If you wanted to completely optimize for low battery degradation you'd charge between like 49% and 51% and only have a few minutes of usage, but that kind of defeats the point of keeping a lot of battery capacity.

Re: Tesla Model S battery degradation data

#138

Post by [deleted] »

photojosh wrote: post #125
stephengillie wrote: post #113

Earlier quoted context omitted.

[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.

[deleted]

Re: Tesla Model S battery degradation data

#139

Post by kmonsen »

elihu wrote: post #135
sorenjan wrote: post #33

Earlier quoted context omitted.

I've never seen anyone put more than one kilo before the unit before.

I guess it's less confusing than using "mm" for "megameters". "I drove my car 266mm" doesn't sound like much of an accomplishment.

mm is millimeters though, so that would be about a quarter of a meter. I guess Mm would be what you are looking for.

Re: Tesla Model S battery degradation data

#140

Post by photojosh »

Coincoin wrote: post #136
photojosh wrote: post #126

Earlier quoted context omitted.

> 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.

>I do like the nerdiness in the idea of saying "two megs" instead of "two thousand kays" But they are not the same!!oneoneone. Unless you are in the dog food prefixes camp. Are you?

2 000 km = 2 Mm?

You're not thinking of the mebi-, kibi-, etc debacle, are you?

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