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Comment by jondwillis | Hacker News Reader

Anecdata: bought a used off-lease 2019 Model 3 in 2021 (NCA chemistry.) The battery had degraded a typical amount (<10%) as they do in the first few years. Since then, I have been doing a pretty good job of following the advice to basically keep the battery >20%, and <80% as much as possible, and only supercharge when absolutely necessary. It hasn’t really degraded much further at all, if the range estimate can be believed.

At the current rate, the suspension and other components seem more likely to fall apart (it was constructed in a hurry, in a tent after all) before the battery hits its EOL. Regardless, I hope to be able to reclaim the degraded cells to use in home energy storage if it is economically viable.

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Anecdata as well: I own a 2022 Jeep Wrangler 4xe that comes with a 17KW battery pack with Samsung Prismatic Cells, battery management includes liquid cooling with chiller, liquid heating for winter months. I've seen about 10% degradation over 3 years, referencing battery SOH data from the onboard battery management module. The last 3 or so months have really slowed down the rate of loss, I'm hoping this continues throughout my ownership of the vehicle.

From my understanding Jeep was really cautious with the battery, on the display you will see 0%, but it's always at least 20% of remaining charge in actuality.

Operating outside of the 20-80 percent range of a battery is what kills it (and high current draw), inside of that range and it acts like a spring. There should be product design laws that make it difficult to sell products that abuse batteries in this way.

NASA did a bunch of longitudinal studies (long time duration , same components over that range) with Lion batteries and found almost no long term degradation after the initial capacity loss. Same for solar panels.

If you could somehow attest (via the BMS?) That a battery pack (and the individual serialized? Replaceable cells?) wasn't operated outside of some bounds, the aftermarket value of that battery pack and individual cells could be quite a bit higher.

I like that. Have the BMS sign its git commits.

I have been toying with a spec for a BMS that monitors and logs the health of every single battery both on charge and discharge.

What is more exiting, is that Sodium cells are much tougher and can be discharged to zero volts and stored in a discharged state. That also means that they can be shipped discharged and items incorporating them don't degrade while on the shelf or in shipping.

> At the current rate, the suspension and other components seem more likely to fall apart

They're trivial to replace when the time comes.

They would be if the makers had the parts widely stocked. One of the issues with Tesla, at least in the past, is they pretended to have nothing to learn from Toyota and Honda, and there just weren't any ball joints, control arms, and wheel bearings on the shelves. Getting your Tesla chassis fixed is a 2-hour job with a 6-month waiting list.

That’s interesting. I had the upper control arms replaced on my model 3 a few years ago. It was a 1 hour job with a 1 week appointment lead time, and that was because I got a mobile appointment where they came to me.

And much much much cheaper too

Can any service replace them, or only official tesla(tm) one? Is there a healthy ecosystem of original oem parts and good 3rd party ones?

I'll never buy a car that a random service cant fix, bmws for example so far seems easy peasy to achieve this, which brings TCO almost down to cheap basic brands.

Anyone who has the necessary training and equipment can repair or replace an EV battery and it is done by a few companies here in Norway.

for instance https://www.batterielektro.no/elbil/, https://carfix.no/carfix-teknikere-kan-apne-og-reparere-elbi...

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