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Tesla Model S battery degradation data

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Re: Tesla Model S battery degradation data

#201

Post by nateguchi »

dx034 wrote: post #187
gambiting wrote: post #186

Earlier quoted context omitted.

I trust the fuel consumption in my car, yeah. If it says I've been using 12l/100km on average and I've travelled 500km, you can bet I'm filling up exactly 60l at the pump.

That really depends on the car. I don't own a car so often use rental cars. Most cars' consumption is within 10% of the shown values but at least every fifth car I drive has vastly different numbers. I think it is not necessarily due to the car but because of the calculation methods they use. If you drive motorway and city, consumption is accurate. But as soon as you start driving in the mountains or a mix of differe…

If the car has a Mass Airflow Sensor (MAF), then it can more accurately calculate the fuel usage. The majority of older / cheaper cars use a Manifold Absolute Pressure Sensor (MAP) and have to make some guesses at what the actual fuel usage is.

Re: Tesla Model S battery degradation data

#202

Post by lathiat »

sliken wrote: post #199
saagarjha wrote: post #180

Earlier quoted context omitted.

If you have a MagSafe connector, cover the middle pin with electrical tape.

Which does what exactly?

blocks the data bus (i2c or whatever it is) used to negotiate with the power adaptor. Will cause it to draw power, but not charge the battery.

Re: Tesla Model S battery degradation data

#203

Post by lorenzhs »

photojosh wrote: post #124
digikata wrote: post #119

Earlier quoted context omitted.

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…

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.

Re: Tesla Model S battery degradation data

#204

Post by roman_savchuk »

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 lifetime, than fooling the customer on purpose. The calculation is based on the effective injector pulsewidth (ECU can't count actual fuel flow))), and as injector performance deteriorates over time, you get less and less optimistic values with more miles.

Re: Tesla Model S battery degradation data

#205

Post by dcustodio »

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.

Re: Tesla Model S battery degradation data

#206

Post by TomMarius »

thinkling wrote: post #81
IkmoIkmo wrote: post #25

Earlier quoted context omitted.

> Average life of ICE vehicles can't be 266kkm, that's absurdly low. I'm not sure it is... I mean, in my country (Netherlands) the average car user drives 13k km per year, in very car heavy countries that's probably around 20k. But here it'd mean a car would last on average 20 years, that's not absurdly low by any standard.

Pretty close. In the US, it is commonly assumed that average mileage per year is 15,000mi (24,000km). Maybe someone could write a quick script to scrape AutoTrader.com or a similar site and see what the mileage is on cars over 20 years old that are offered. ;-)

Not sure about the US, but in Europe, you can never trust the odometer. Displayed mileage is often a third or a quarter of the real mileage.

Re: Tesla Model S battery degradation data

#207

Post by alkonaut »

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…

Then there is the average being pushed down by cars scrapped because of accidents or massive failures such as big engine failures with low mileage.

Also: Here we have a very strict road legality checkup (joints, breaks, rust, lights, belts, ..) for all cars. Once a bad/cheap car reaches the age when it starts failing the checkup, it's often not worth fixing. So while it could probably do another 100kkm with the dodgy wheel bearing, it's not allowed to without immediate expensive repair. So these checkups effectively purge every car that would need repairs to any vital parts costing more than its worth every year.

I have a 10 year old peugeot worth around $1-2k that has gone 18kkm. If it were to fail a checkup for even something simple like a wheel bearing or uneven handbrake appliance - I'd probably hesitate to repair it because I could just as well get another one (A recently checked one for $1k would limp along at least 1-2 years to the next checkup while mine is banned from the road immediately).

Re: Tesla Model S battery degradation data

#208

Post by visakanv »

ashark wrote: post #68
seszett wrote: post #22

Earlier quoted context omitted.

165 000 miles is 266 000 km, for the readers who might wonder. My car is at 350 000 km now, and I'm not planning on selling it anytime soon. It doesn't have any special problem, except for a malfunctioning electric window lifter on one side. It's only one data point of course.

> except for a malfunctioning electric window lifter on one side. There's probably a Youtube video that'll walk you through how to replace it. I replaced the one on the driver's side door of our 2001 Honda Odyssey last year. I think it was like $120-150 (USD) for the part and 3ish hours. I know almost nothing about fixing cars (just generally how to use basic tools), but have used info from forums and (especially) yo…

People making YouTube videos to teach strangers how to do things is one of my favorite things about the human species :')

Re: Tesla Model S battery degradation data

#209

Post by ZeroGravitas »

acchow wrote: post #134
digikata wrote: post #119

Earlier quoted context omitted.

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.

I'm sure that one of the Tesla founders stated that one of the reasons that device batteries failed after a couple of years is because longer life wasn't prioritized by the companies buying them and so not much effort was put into that dimension.

You can spin this in a bad way ("planned obsolescence") or a good way (they were optimising for other things that customers valued), but the point remains the same, if car manufacturers (or grid storage units) require longer lifetimes, then it's not a hard physical limit at the current lifetimes that's been hit yet.

Re: Tesla Model S battery degradation data

#210

Post by jeffhuys »

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…

kkm, is that kilo-kilometer? Could we also say megameter? I like that word.
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