I always imagined Tesla were going to develop/produce their own batteries.
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Must be pretty hard to do it, maybe? Musk does like to have a vertically integrated supply chain, so Panasonic must be bringing some benefits.
Are EV batteries literally made up of hundreds of these cylinder batteries?
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Yes they are. It’s probably actually thousands as a Tesla battery pack weighs about half a ton
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Around 7000-8000 cells depending on battery and car model.
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I always thought it was like big square packs, not thousands of these tiny ones.
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The cells are getting bigger, so more like 4k in a Model S I think.
At least they don’t come with a sticker saying “Batteries not included”!
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So ~21% of battery space is wasted, the ratio of a circle to a square. That’s not including the thickness of the casing.
I will invest in any company that can make a square battery, instant 20% capacity gain.
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Yes, you are right there @AchillesFirstStand filling that space would make a huge difference… but not all of it is wasted space…
I understand that these cells get incredibly hot in use and so require liquid cooling pipes between each cell and the cylindrical canister of individual cells probably maximises surface area with the coolant pipes. Square cells would need a clever cooling system to ensure thermal stability, but someone might come up with a solution.
Apart from the cooling issues, I would imagine that the manufacture of cylindrical cells is considerably cheaper than square cells and so the gain in energy density per volume may be too expensive.
Cylindrical cells are probably the best option for now.
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Power density, manufacturing, thermal considerations and cost are far more important than volumetric efficiency, because frankly cars have a lot of free space.
Other shapes exist but I don’t think packing density is a key driver in most applications, phones being an obvious exception.
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Speaking of coming up with a solution… Tesla’s solution is to immerse the batteries in a dielectric … solution. Again, surface area and space would be required for flow, so they may as well keep the cheap to manufacture cylinders.
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Yeh, I was obviously being facetious 
. I would assume the main driver is the cost of manufacturing a cylindrical battery as batteries are made of wrapped sheets?
In terms of efficient shape for cooling, I doubt it’s cyclinders. A circle has the worst surface area to volume ratio.
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There was a photo this morning of an army truck delivering a load of them.
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Seems that they need to be used with caution as they can be used as beacons to be targeted
See for example an example where someone was previously targeted as he was using a satellite phone
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Regardless of the awful war in Ukraine, Musk seems committed to Europe and Germany in particular.
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Hi everyone,
So what do we all think of Cathie Wood’s price prediction on Tesla of $3k by 2025.
Given her past prediction, surely she must possess clairvoyance? 
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Personally, just my humble opinion, I think it’s ridiculous! At 1200 Tesla stood higher than Amazon despite being basically a luxury car company. 3k suggests that it would be basically in the running with apple, microsoft, google. How much money can there really be in general for people to pour in to Tesla? It’s already the size of Ford and GM. I believe a mean reversion is imminent for Tesla. I guess we already have seen the start of it with it dropping from 1200 to ~700 though. At the very least I think Tesla investors need to realise that there’s a lot of dumb money in the company they’re buying a stake in, and that one bad earnings report could send it tumbling down.
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