this post was submitted on 06 Oct 2023
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Yeah, of course... But they're also replaceable. You can even check the individual cells, swap out the worst ones with cells from other used packs, and end up getting back up to decent capacity. There's a whole statistics, mean time to failure aspect to batteries - it's not going to take them back to new, but swapping out the worst cells can get you a lot better performance
Or you could just replace the batteries with newer, likely better, battery banks. The first option needs a certain scale, but would be cheap, the second would be a straight range upgrade over even the factory range.
There's also the fact that electric cars are much more mechanically simple - this is unlikely to catch on under our current economic system, but it's way easier to swap electric motors than an engine...
My points being, I think we need to make way less cars, and electric cars are actually easier to repair (at least from a physics and resource perspective, hostile design and economic pressures could easily eat up that difference)
we need right to repair laws for cars so this is possible
The problem with replacing individual cells is you'll end up with cells with different wear levels which means different discharge rates and capacities (max voltage). The battery management system can mitigate some of the problems that arise but can only do that while chargering. While the battery is in use or sits for an extented period of time the cells will try to level out the voltage difference causing loss in capacity and a potential fire risk if the cells are too out of balanced.
Replacing the battery with new better batteries isn't really an option either as any significant increase in power density would be from a change in battery chemistry and that would also require changing out the on board charging circuit and related systems. There's also the issue that the majority of charge points providers state in their TOS that the use of any aftermarket parts or modifications to your battery or charger is forbidden so you are essential blacklisted from using any DC fast charger.
That's why I mentioned pairing cells from multiple used battery packs... This isn't magic, it's numbers... You pair like with like, and by removing the underperforming cells, you get rid of the dead cells bringing down the whole bank because they can't hold a charge. The fire risk is also greatly overstated... Batteries and management circuits have come a long way. You could swap in new cells and it would be fine... It would just be a waste, the new cells would degrade faster than their spec sheet implies.
And as far as matching like with like, you can build a lithium cell tester at home to profile each cell for a few dozen dollars... Literal hobbiest level stuff
And you most definitely can upgrade with newer, better batteries. There's three numbers - energy density, voltage, and discharge rate. You can upgrade the density to the moon, so long as the other two match it's a drop in replacement... And these three things are a tradeoff when you build the battery, so a better battery bank with the same output and voltage is just going to make you car run further, easy as that.
Yeah, TOS might stand in your way, but that's economic pressures, not an engineering issue. We could entirely solve that problem through force of law. On the topic, let me take this opportunity to promote right to repair - companies are going to feed us a lot of bullshit reasons why we need to throw it all away and replace everything fresh... They have every incentive to make us believe that. It's less work for them to say "that's not an approved use", they make far more money if they convince us they are the only ones that can fix it... it's an economic alignment problem, the engineering solution is well understood