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Tesla Model S battery degradation data

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Re: Tesla Model S battery degradation data

#231

Post by linsomniac »

jakobegger wrote: post #182

Doesn‘t anybody find it curious that the source of data are range estimates displayed on the cars built-in dashboard? For all we know, Teslas might be programmed to show more „optimistic“ estimates as the batteries get older. I‘m not saying this is actually the case, but these stats are effectively manufacturer-provided numbers. Would you trust data like this if it came from any other car manufacturer? If you have a…

The Tesla is strange because that number on the dash is "rated miles", or the best you're going to get. So you can't just drive to empty and get a number you can compare with others, unless you drive it in quite a certain way.

My S60 says something like 215 miles when fully charged, but when driving on the Interstate the actual range is more like 160 miles, with the cabin heater on. It can vary significantly due to rain as well, a recent trip that had a leg almost entirely in very heavy rain caused a significant drop in range.

Re: Tesla Model S battery degradation data

#232

Post by stephenc_c_ »

dcustodio wrote: post #205
jakobegger wrote: post #182

Doesn‘t anybody find it curious that the source of data are range estimates displayed on the cars built-in dashboard? For all we know, Teslas might be programmed to show more „optimistic“ estimates as the batteries get older. I‘m not saying this is actually the case, but these stats are effectively manufacturer-provided numbers. Would you trust data like this if it came from any other car manufacturer? If you have a…

I fill up every time I refuel and I take notes of the quantity and odometer and the average matches the dashboard.

There is a website you can use to keep track of this: http://www.fuelly.com/

Re: Tesla Model S battery degradation data

#233

Post by justin66 »

roman_savchuk wrote: post #204
jakobegger wrote: post #182

Doesn‘t anybody find it curious that the source of data are range estimates displayed on the cars built-in dashboard? For all we know, Teslas might be programmed to show more „optimistic“ estimates as the batteries get older. I‘m not saying this is actually the case, but these stats are effectively manufacturer-provided numbers. Would you trust data like this if it came from any other car manufacturer? If you have a…

When I was reverse engineering car ECUs, one of the interesting little projects was finding fuel consumption display calibration data and calculation algorithm, on 2008+ Subarus. And then I did some measurements trying to get accurate real world consumption, and "sync" the dashboard with it. And while there was ~3% error IIRC, I think it has more to do with getting the most accurate average consumption over the car's…

> ECU can't count actual fuel flow

Thanks, this is pretty interesting.

It's the first non-bullshit explanation I've seen for why cars tend to display inaccurate average MPG on the dash. I always assumed there was a fully accurate measure of fuel flow into the engine and there was something else broken (or dishonest) about that calculation.

This has come up in the press occasionally and the manufacturers never admit that they don't have a totally accurate measure of flow: https://www.edmunds.com/fuel-economy/your-fuel-economy-gauge...

Re: Tesla Model S battery degradation data

#235

Post by gambiting »

lorenzhs wrote: post #203
photojosh wrote: post #124

Earlier quoted context omitted.

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…

I know ThinkPad laptops have this (mine is set to charge up to 90% and only start charging if it's below 80%), and I think I've seen it in some custom kernels for Android ROMs a few years ago, but I'm not aware of any popular devices supporting something like this.

Sony phones have that, I have an Xperia Z5 and you can select an option to "prelong battery life", where the phone only charges it up to 80% and stops(the scale shifts, so 80% shows as 100%, but internally the battery is never at 100%).

Re: Tesla Model S battery degradation data

#236

Post by radiorental »

graylights wrote: post #85
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…

Sounds like a case of survivors bias. Cars totaled in accidents likely bring down the average.

And Fiats.

Re: Tesla Model S battery degradation data

#237

Post by SAI_Peregrinus »

dx034 wrote: post #188
myrandomcomment wrote: post #181

Earlier quoted context omitted.

It can be more confusing. US date - m/d/y. Distance in miles. If you are in the US military - d/m/y and klicks (km). Was in UK a few weeks ago and rented a car, mph for speed, everything else (except beer) in metric.

The UK is more complicated than that. Most of the signs are in metric but some distances are in yards and heights are in feet. Petrol prices are in litres but consumption is in mpg, even though there's no indication on how many gallons you actually fill up. In stores, everything has to be metric because of EU regulation but packaging for liquids is often in pints (e.g. milk, beer) and then gets translated into litres…

Eh, not everything is consistent. Soda cans are 12 fluid ounces, but bottles are 18 ounces, or 1 or 2 liters. Hard liquor comes in 750ml bottles, but is served in 1.5 oz or 2 oz shots. Beer comes in 12, 16, or 24 oz cans or bottles, milk in gallons, quarts, and pints, etc. British pubs tend to serve beer in imperial pints (20 imperial fluid ounces or about 568ml) instead of US pints (16 US fluid ounces or about 473ml) but other bars serve US pints.

There are other oddities and mixed units. Dates are in "drunk endian" with month/day/year format, indoor areas are measured in square feet and outdoor areas in acres... Small units of length are in fractions of an inch unless you're a machinist at which point they're in "thous" or "mills" (same thing, 1/1000 inch) or "tenths" (1/10000 inch). Drill sizes are fractions of an inch for some common sizes and large diameters (27/64 and up are always fractional), but otherwise are numbered starting at 80 and decreasing down to 1 as diameter increases with the spacing between numbers being inconsistent, except for a series starting at 2340 thou and ending at 4130 thou which is lettered with 40 thou between letters (mostly, some inconsistencies here). But you can still get drills in some of the fractional inch sizes that fall between the letters. Seriously, look at a tap drill chart[1]. And of course if you're a machinist you'll also have to deal with metric items imported from the rest of the world or made for sale there so you'll also need all the metric drill and tap sizes.

[1]http://www.brokenbolt.com/images/starrett-inch-metric-tap-dr...

Electric systems use SI units, except that PCB designers tend to use thou for trace sizes and spacing. Some components have pin spacing in thou, others in mm. Getting the PCB to look nice with a mix of pin pitches and grid sizes is more of a chore than it should be.

Re: Tesla Model S battery degradation data

#238

Post by agumonkey »

Slartie wrote: post #223
jakobegger wrote: post #182

Doesn‘t anybody find it curious that the source of data are range estimates displayed on the cars built-in dashboard? For all we know, Teslas might be programmed to show more „optimistic“ estimates as the batteries get older. I‘m not saying this is actually the case, but these stats are effectively manufacturer-provided numbers. Would you trust data like this if it came from any other car manufacturer? If you have a…

I currently drive a 2015 Opel Astra. It shows an average of 5.1 liters per 100 kilometers (sorry, German, so it's metric units for me) over multiple months of driving in the dashboard. At the same time, I'm tracking every one of my gas refills using an app which also calculates consumption averages over arbitrary timespans. By that data, I am actually consuming about 6 liters per 100km, which is an almost 20% deviati…

I'd put this in a typical market drift. New generation are built with a lazy cheap mindset, not the old generation "lets try to make something good (probably because there was more love and motivation for said product at that time)".
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