Battery breakthroughs
- Thread starter Domenick
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Martin Williams
Active Member
Just as a matter of interest it is conceivable to design batteries that will 'correct' internal shorts, by simply burning the short out. I recall a particular type of capacitor having this feature. A short resulted in evaporating away the material around the short. A tiny decrease in capacity resulted, but it was, in practice, negligible.
7,000 cells in a car is a laughable solution. What is known in engineering as 'a kludge'. An ugly, expensive, bodged piece of design.
A small number of large cells is a much neater solution if it can be done. But I suppose if you are wedded to lithium-ion batteries, a very large single cell would probably behave like a small bomb under fault conditions.
7,000 cells in a car is a laughable solution. What is known in engineering as 'a kludge'. An ugly, expensive, bodged piece of design.
A small number of large cells is a much neater solution if it can be done. But I suppose if you are wedded to lithium-ion batteries, a very large single cell would probably behave like a small bomb under fault conditions.
Pushmi-Pullyu
Well-Known Member
Oh, come on Jim, don't pee on our legs and then try to tell us it's raining. Your phrase "connecting hundreds or thousands of small cells to form a battery" cannot possibly refer to any production EV other than Tesla cars.
Are you that confused about the facts, or is this a bait-and-switch argument? Panasonic makes the cells for Tesla's battery packs, yes. Panasonic certainly does not "connect hundreds or thousands of small cells to form a battery"; Tesla does that.
Using commodity li-ion battery cells was the option Tesla used, when designing and building the original Tesla Roadster. But it certainly was not the only option. Several makers of production mild hybrid EVs (HEVs, not PHEVs) were using NiMH battery packs at the time. That's what GM used in the 2nd generation of the EV1.
You say "space inefficient"; I say "sufficient space to allow proper cooling". If you want to see what happens to large prismatic cells which are crammed together with no cooling system, just look at all the problems Boeing had with battery fires in its Dreamliner!
You claiming that the interconnects between small cells add enough resistance to waste time arguing about, claiming that without providing any empirical evidence at all, does not rise to the level of a real argument, let alone proof.
As far as costly assembly: Well, I think the real question is about pack assembly costs as a whole, not the cost of making individual connections. Unless you can point to some evidence that Tesla's pack-level costs are significantly higher as a ratio of cell costs, as compared to battery packs from other EV makers, then again that's merely a claim you're making without proof.
I don't know that I would go so far as to "deny" it, but I am certainly skeptical of a claim that this problem is entirely or even primarily due to over-complexity of Tesla pack assembly. According to one report about the problem, one which seems to be more objective than most, the actual root cause is Tesla's engineers disagreeing with the company which made and installed the failed automated assembly line on how to set up that assembly line. I don't care how complex or simple the design is; if those trying to install the assembly line had fundamental disagreements with those who would be running it, then that's a recipe for disaster right there. No other added cause is needed; that one is entirely sufficient to explain the failure.
WOW! Over-react much, dude? Maybe you should take that enormous chip off your shoulder, take a stress tab, and recognize that I was agreeing with you. Duh!
As far as 7-year-old arguments... I think you may have overestimated the maturity you displayed right there.
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Pushmi-Pullyu
Well-Known Member
Well, the Leaf's battery pack is certainly simpler.
NO, it is not- just a lot smaller & lacking temperature control. Still has a mass of torch batteries.
The Leaf battery pack is far simpler than a Tesla battery pack. It has far fewer parts. Fact, not opinion.
1. The 24 kWh Leaf battery pack has only 192 cells, as compared to the thousands of cells in a Tesla pack. That's not only far fewer cells, it's far fewer interconnects.
2. The Leaf battery pack has no cooling system. At all.
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Pushmi-Pullyu
Well-Known Member
Martin Williams
Active Member
Quite so. Lithium ion batteries are pretty lousy from many points of view, but they are being used because there isn't an alternative.
Lead acid cells are probably better in most respects except energy density which rules them out for battery cars. Where their weight and bulk are not important, they are the battery of choice. Not perfect of course, but cheap, recycleable, high current, easy to maintain and replace, temperature tolerant, and pretty rugged. And a lot more stable than lithium ion. Its a sad fact that 150 year old technology is better than the best modern technology can offer in so many deployments!
Lead acid cells are probably better in most respects except energy density which rules them out for battery cars. Where their weight and bulk are not important, they are the battery of choice. Not perfect of course, but cheap, recycleable, high current, easy to maintain and replace, temperature tolerant, and pretty rugged. And a lot more stable than lithium ion. Its a sad fact that 150 year old technology is better than the best modern technology can offer in so many deployments!
My opinions are not the issue. These are NOT my claims- Just READ the article and disagree with it/ them.
1. "connecting hundreds or thousands of small cells to form a battery" cannot possibly refer to any production EV other than Tesla cars
I don't know or care who first did this, it is the standard method right up to present for most EV's. And it ignores the KISS principle. The 'only option' meant the physical cylindrical cell, not the chemistry which ought to be obvious from the context.
2. I did NOT say Panasonic did the pack assembly. No need to lie, Pu-Pu, just re-read.
3. I DON'T say 'space inefficient'-the article says that. I quoted it so people who didn't want to read the article would know.
FYI, since you evidently won't read it, the claim [NOT MINE!] is that 50% of space is wasted in cell containment pack assembly & connections.
4. Battery costs--https://www.iav.com/sites/default/files/handouts/2016/en/embatt-technology.pdf READ IT. Stop personalising.
5. 'Chips on shoulders'? Personalising again. [I notice your gigantic chip is 'fool cells' as you call them. Impractical in small EV's but who knows what niche they might occupy- not you, nor me. I reserve judgment on those, despite the obvious shortcomings].
6. Agreeing with me? Then it might pay if you used simple, clear English, not abstruse horse-n-hay analogies.
7.How about, just ONCE you put up links to support your opinions?
I DON'T CARE to continue this pointless 'discussion' with you. You are at times fairly emotional, insulting & irrational- eg "According to one report"... what 'report'? Yeh, very scientific and convincing. I hope fervently that Tesla succeeds but it's recent performance raises doubts. Musk is a visionary & possible genius [that word has been devalued much in recent times] but is uncomfortably similar to his namesake in some ways. Eccentric, obsessive, clever but flawed. Colonise Mars? What the hell for? What sane person would live in that hostile barren dead-end; the problems are here on Earth & he is fully aware of that, obviously.
So you are on my ignore list, for now.
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WHO are you addressing?
Martin Williams
Active Member
I assumed it was me, Jim.
It seems one has to spout the one true creed here. Rational debate or disparate views are not encouraged.
It seems one has to spout the one true creed here. Rational debate or disparate views are not encouraged.
galderdi
Member
Fair point, I guess an interest in an outcome is as good a reason as any.
Slight clarification though. I believe electric cars have a bright future. The best way to get the electricity to run them is a different discussion. I am neither an expert in batteries or a clairvoyant so I don't claim to know what the best source of electricity will be in the future. Nor do I care. So long as the source become better and cheaper I will be happy.
A simple definition for a battery is (according to Google): A container consisting of one or more cells, in which chemical energy is converted into electricity and used as a source of power. So that would include a very wide range of technologies....including Hydrogen. Unless there is only one cell. Hydrogen vehicles are still powered by electric motors and are therefore still an EV.
So I am still a little confused. If you think EVs are doomed what do beleive will be the vehicle of the future?
Pushmi-Pullyu
Well-Known Member
I certainly agree with you about colonizing Mars. I think it's time to seriously consider a manned mission to Mars, but why would anyone want to live there? You'd have to live like a mole -- spending most of the time underground, only occasionally emerging on the surface, due to all the radiation that's not blocked by an almost non-existant atmosphere.
I'd love to see a long-term project started to terraform Mars; probably very long-term, on the order of centuries. But who in his right mind would want to live there now, or in the near future? If someone wants to create a habitat off the surface of the Earth, it would make far more sense to create an O'Neill type colony in orbit around Mars, or any other planet, than to actually try to plant a colony on Mars when it's so very hostile to life!
I agree with Musk's overall mission re planting a colony on Mars; I think that it's very important for the survival of our species to create a self-sustaining colony on some other planet as soon as possible, as a guarantee of our species' survival if some mega-disaster should happen to planet Earth. But Mars could not possibly support a self-sustaining colony until it has been at least partially terraformed, so what would be the point of planting a colony there which would die off if it wasn't supported by regular supplies from Earth?
That seems best. Perhaps when you calm down we'll be able to discuss issues without you getting emotional and upset over someone simply disagreeing with you.
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Martin Williams
Active Member
I apologise. I too think that electric cars -if the energy is stored in hydrogen which is used in a fuel cell - have a bright future. I should have said cars which attempt to store the energy in electrochemical batteries are doomed. I don't see batteries improving much for the foreseeable future.
The arrival of much better capacitors might change the picture, but I feel also that getting large amounts of energy into the vehicle quickly is going to be difficult to achieve due to the high power levels involved even with perfect batteries. Hydrogen will still be a better way of doing this. Good capacitors could, however, improve such cars also by eliminating the need for them to have batteries.
I really don't see why hydrogen cars are attacked with such venom here. They ARE electric vehicles after all, as you point out. They just have better batteries!
I'm guessing this was stated in the sarcastic thread about Hydrogen cars, but to try to put it simply for @galderdi - people here don't like Hydrogen as a car technology because it's a talking point that's used to delay the decarbonization of transportation. "Don't worry about pushing electric cars, they'll never work, and Hydrogen cars are just around the corner!"
People who promote hydrogen keep saying it will be great at some point in the future. But it's not viable now and probably won't ever be, except in maybe specialized circumstances. (Trans oceanic shipping?) Hydrogen as a transport fuel is far less efficient than battery electric cars, and it's still a fossil fuel, since most of it comes from processing methane, and there are almost no filling stations available anywhere. The state of the climate crisis means humanity needs to start dropping emissions rapidly within the next 2 years, so any delays are very damaging and really frustrating to anyone who is concerned about the future of humanity.
There are maybe 4000 Hydrogen cars on the road currently, making not a dent in oil demand or emissions. In contrast, there are probably more than 2 million PHEVs and BEVs on the road already, with significantly more to come, and they are already making a dent in oil demand in China. Battery electric vehicles are viable for many people already now, and with all the longer range models coming out soon, they will be viable for most people within 5 years, unlike hydrogen cars (never).
Domenick
Well-Known Member
That's been explained to you a number of times. It's because they are seen as an inefficient use of resources and effort.
It's fine that you think they are a realistic alternative. Plenty of others agree with you. I only ask (again) that you discuss hydrogen in a thread other than this one, which is for developments in batteries.
Martin Williams
Active Member
Will do. I answered a post here which involved it, but I will address it in a new thread "Are hydrogen tanks superior to batteries"
terminaltrip421
New Member
I would add fracking is hazardous to life on this planet as well. sorry to have further kept it off topic.
on topic: https://www.nextbigfuture.com/2018/...d-be-twice-as-good-lithium-ion-batteries.html
to think batteries aren't going to improve is like standing in the computer rooms of old and thinking the tech had likely reached its apex. perhaps compare the $$ (accounting for inflation) being invested in developing those technologies over the years and that of battery technology research today.
it's not as if it's just cars that are itching for better batteries; do you think electricity production + storage is something that has gone unnoticed by the world's deepest pockets? speaking of said pockets, those devices they're selling or making parts or software for run on batteries too and boy do their customers want better ones.
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Pushmi-Pullyu
Well-Known Member
Indeed! Predicting that batteries have suddenly reached the practical limit of development, after more than 30 years of continuing improvements, is about as forward-thinking as Bill Gates predicting in 1981 that "640k of [computer] memory ought to be good enough for anyone!"
Right. The need for longer lasting batteries for cell phones and laptop computers is probably an even bigger economic incentive driving battery R&D than the EV industry is.
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