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I believe earlier Tesla's used induction motors - which don't tend to have any permanent magnets. The advantage of permanent magnets is pretty small - maybe a c
by leoedin 2y ago
I believe earlier Tesla's used induction motors - which don't tend to have any permanent magnets. The advantage of permanent magnets is pretty small - maybe a couple of percent efficiency. They weigh less, but motor weight is hardly dominant in EVs anyway.
The only real resource usage concern for EVs remains the batteries.
- dheera 2y agoI'm not an expert on batteries but why are sodium batteries not a thing? It seems sodium would be much easier to procure across the Earth than lithium.
- bluGill 2y agoThey are, but building them safely and to high capacity is tricky. So far the lithium we can make is better than the sodium batteries we can make. Though this is an area under active research and so what I wrote is likely out of date. Lithium availability is not the limit to current batteries though.
- dgfitz 2y agoSame reason most large corporations hardly pay any taxes, I imagine.
- papercrane 2y agoSodium batteries are a thing. There hasn't been much commercialization of them yet, but the main issue for cars is they have lower energy density than lithium batteries. Currently sodium battery makers are focused on stationary battery applications where energy density is less important.
- osrec 2y agoSwappable low cost sodium batteries are where I think cars may end up in the future. Literally, pull into a swapping station, and have your battery swapped out for a charged one in a couple of minutes. Probably faster than fuelling up your car with petrol.
- matt2000 2y agoThis is kind of happening at scale in China right now (only some brands are pursuing it though): https://restofworld.org/2024/ev-battery-swapping-china/ https://restofworld.org/2024/ev-battery-swapping-china/ It's an interesting trade off between swapping station cost and time to charge. I suspect charge times will decrease enough that it's not worth all the physical investment in swapping, it may already not be.
- magicalhippo 2y agoSwapping for regular cars is a dead end I think. But for trucks and such I imagine it makes a lot more sense. Much longer charging times vs a quick swap. Much easier to put battery in an easy-to-swap location. Fewer swapping stations needed before it makes sense to utilize it for transportation companies, ie team up with a company that has a few fixed large-volume routes to get going.
- jjoonathan 2y agoSounds like a big step back from the car charges at home and is "always full" without ever "filling up", except on roadtrips, where it schedules periodic rest stops.
- gregmac 2y agoDoesn't preclude charging at home. Just means "swap stations" instead of charging or gas stations. The (major) challenge is what you do with 400-800kg of batteries and a bunch of different vehicle types from different manufacturers. Standardize the size/placement so a robot can do it? Break it down to smaller pack sizes so a human -- driver or attendant? -- can do it? Have each car manufacturer have their own set of stations? Took everyone long enough to agree on a plug, would it be possible to agree on a swappable pack?
- stetrain 2y agoThis either requires 1) Different swap stations for every brand of car or 2) a majority of car brands agreeing to use a common size, shape, and spec of battery pack across their vehicles. Personally I don't see that becoming a reality anytime soon at least in the US.
- pkulak 2y agoLess kWh per unit mass and volume.
- KennyBlanken 2y ago...which is fine for energy storage systems in homes, businesses, campuses, and substations.