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Tesla lowers Model Y, S, and X range estimations following exaggeration complaints
(www.theverge.com)
this post was submitted on 05 Jan 2024
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Wind and pavement won't make 5 miles into zero miles in a few seconds.
I once read a description of battery metering where the best you can do is read current over time, and estimate where you are by the slope of the line. That can easily change drastically from one second to the next.
I still think the problem s an overly precise estimate, and the false confidence of someone thinking it is exact. Even digital technology is implemented in analog and some things just don’t have exact answers
In the case of Tesla there is ample evidence that they intentionally lie about range so it doesn't matter how hard it is to guess when we already know they are lying.
Not denying that, but I’m also not relying on an estimate so close to zero
At least you have common sense. Seeing other replies is befuddling. Yeah Tesla lies constantly, but literally no EV has bulletproof estimates.. because they can't have that. And trusting an estimate as fact is just so weird to me.
That means Tesla's claim that supercharging stations allow you to make long trips is a lie. When you charge at a Tedla supercharging station, the Tesla tells you where to drive to the next charging station to not run out of charge. If range cannot be estimated such that you can't reach the next station they tell you to drive to, their Supercharging network claims are lies.
I completely agree. Also, yes they can. Predict the rate of change based on the amount used over the past hour or so and adjust. Gas cars do this already, so I'm sure electric cars do
Erm, that's not the issue. Gasoline cars have gasoline in the tank, meaning its very easy to estimate how much fuel you have left. In fact its not an estimate at all, its a direct measurement of gasoline in the tank.
The charged electrons inside a Li-ion battery? No good estimate methodology. I'm serious. You can't measure with a dipstick, there's no float-bob, you can't weigh, you can't do jack diddly shit with Li-ion batteries from any physical perspective.
What Li-ion estimations are is something called "coulomb counting". You count the electrons in, and count the electrons out. Guess what? It gets inaccurate when things like internal-leakage changes based off of the temperature changes over the past week and a half of charging. This is why phone Li-ion batteries can shutoff at "10%", because those electrons leaked out in a way that the colomb-counting sensor was unable to detect. (Many, many different sources of leakages).
Its like trying to measure the amount of gasoline in your tank by simply measuring the gasoline in and out of a gas-tank. But what about evaporation? What about a whole slew of other issues? You just can't plug all leaks in gasoline tanks or Li-ion. But you can just weigh the gas-tank to figure out how much gasoline is there, or you can have a float-bob that tells you how far the gasoline is from the bottom of the tank directly. But literally no such technology exists (or ever existed) for Li-ion.
Maybe in the future this could be invented. But this "last bit of charge phantomly disappeared" is almost innate to battery-tech, at least with today's level of technology.
In fact, measuring the "zero point" of any battery is famously one of the most difficult problems in battery tech. The only way that seems to reliably work is by discharging the battery all the way to 0% so you know for sure where it is. But otherwise? Good luck finding it (and you shouldn't discharge to 0% because it damages the battery anyway). So the columb-counting methodology gets less-and-less accurate over time as all of these leakages or other problems add up... and since the 0% point is rarely reached, there's almost no way to calibrate in practice.
So ... blame the consumer for their ignorance? Require a class before they can buy an electric car?
Errrmmm I don't know what your point is
I'm saying that this problem is innate to any and all electric vehicles with today's level of technology. And Elon Musk is a fucking liar for trying to suggest that "battery fuel gauges" can reliably determine the "last ounce" of charge.
The honest thing to do for EV proponents is to make sure people know the tradeoffs, so that no one tries to go down to 0% charge unless they absolutely have to. Or maybe for us all to encourage battery-chargers for cars to discharge the battery fully on some occasions (to reliably figure out the zero-point calibration). I dunno what the best solution is, but liars spreading lies about how EVs work is bad for everyone.
The consumer is obviously being misled by Tesla (and Elon Musk) on this matter. And that's before the shitty range-estimates come into play (literally a conspiracy where Tesla employees have documents that prove that they know about how bad some of these range estimates are, but are working to prevent the public from knowing about it). Some of it is understandable given the difficulty of the problem of battery-estimation. But its always wrong for the company to take an official stance to lie to their customers.
Tesla has temperature sensors. They could give estimated range at the start of a charge based on current conditions. It was only a few hours between supercharging stations. The temperature didn't change dramatically between 11pm and 2 am.
But they don't do that for marketing. People would be returning their new Tesla's bought in the winter when they started it for the first time and it said 150 mile range instead of 250.