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Comment by mikeash | Hacker News Reader

I'm wary of comparing with laptops and cell phones, because a proper EV drivetrain will suffer much less degradation. Consumer electronics batteries are poorly cooled and prioritize daily capacity over long-term life, so they degrade much more quickly. I'm sure you know this, but I see a lot of people thinking their car battery will only last 2-3 years because that's how their cell phone is.

For what it's worth, I appear to have an outlier, but my Tesla's battery has degraded well under 1% after 2.5 years and 40,000 miles.

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I thought I read, perhaps here, that Tesla over-provisions its batteries and uses software to optimize the battery "working set" to minimize perceptible range degradation.

Tesla actively cools its batteries and chose a long lasting battery chemistry. The Leaf, does not cool the battery, and the early Leaf model had a really bad chemistry.

Not sure why you got downvoted for this. Nissan and some other manufacturers seem to be cutting costs by not doing the active cooling/heating that GM and Tesla are doing, and consumers are suffering for it. I was very disappointed to see the new Leaf is still not thermally managed. Air cooled only. Probably fine for California, but in places that have deep winters and hot summers, it's a bad idea.

Yes, I would have seriously considered the new Leaf, since it is about $5k cheaper than the Model 3. It would effectively cost $18k in Colorado vs $23k for the Model 3.

It would be nice to have the Nissan service and manufacturing capability behind the product. But since it is still designed to degrade, I won't consider it.

GM has said since the Volt was in pre-production they can't imagine why someone wouldn't actively manage the heating/cooling of a battery in an EV, because GM absolutely has to deal with Michigan winters. It's a strange "benefit" to classic Detroit car culture that they live in and take for granted at least one of the temperature extremes.

I'm sure they do, I thought this video[0] was pretty interesting. He took a bunch of Tesla owner's datapoints and mapped it out. The battery will basically last you 25 years.

[0]https://www.youtube.com/watch?v=Gb_i4ihsJ1w

I don't believe they hide degradation. They do use less than the full capacity of the batteries in order to minimize degradation, though. Lithium batteries hate extremes, so if you map the official "0-100%" range to an actual range of, say, 10-90%, that will greatly prolong the life of the battery.

Even without doing that, 0% on lithium ion batteries is not actually 0%. Because once you deep discharge it you can’t recharge it again safely.

This sounds like the Volt. It is software limited to only use the "sweet spot" charge range of the battery, so that it never gets fully charged or discharged. This means that over time as the battery degrades, the user would still see the exact same range due to the system expanding the min/max allowed charge.

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