Batteries and New Battery Technologies

But Bert, this is a very lossy and inefficient way to deliver power, so will end up being impractical. The best way to deliver power with high efficiency and low losses is to keep the whole system at as high a voltage as possible. Resistive power loss, which is far and away the greatest cause of poor efficiency, is proportional to the square of the current.

Let's assume that you can get your total system effective resistance down to around 20mohms (that's the sum of all resistive loss components, wiring resistance, effective resistance of the motor controller, circuit breaker/switch contact resistance and motor winding resistance).

Let's also assume that you want to deliver around 10kW of power input to the electric motor.

For a 300V system the current will be 33.3A and the resistive power loss in the whole system will be 22 watts.

For a 300V system down converted to 12V the current will be 833.3A and the resistive power loss in the whole system will be 13,889 watts.

Does this illustrate why it isn't a good idea to do as you suggest and run at such a low voltage?

Jeremy

 

Some calculations were done for supercaps on the electric vehicle forum by an EE a year or so ago that show it is not even close. I don't remember the exact numbers, but lithium wins by a very large factor in total storage capacity, maybe 10 to one. Supercap of the same size wins in ability to deliver power that last only a few seconds duration by maybe 100 to one.

Porta

 

Well Porta, that says it all. Without an approximately equal storage capacity, indeed it is not a proposition, even while the fast charging was a big plus. Oh well, lets wait for the next solution. But I am a funny guy, I am aware that in a conventional capacitor, the electrons are removed and stored at the surface of the layer not in the layers itself. If one can store all those electrons in the actual thickness of the plates (layers), all the anti arguments are no longer valid. I thought that EEstore had resolved that problem. The question is, did the oil companies buy them out, or did they made a mistake and it was not true what was confirmed by an outside company? Or is it like the water engine, which was kept in the safe ?
Bert

 

Conspiracy theories

Previous post - if Phillips were hiding such technology, as a shareholder I and my co-owners would hound the execs into jail pretty quickly for destroying value. Something like that would get out, it's worth trillions, not just billions. Further, a company like Phillips would be positioned to be the massive beneficiary, I see absolutely zero logic to their being bribed by energy companies to deep-six products like this if they existed. Which they don't.

 

I made one with MosFets. The energy is stored in the ferrite choke basically, when switched by the self adjusting multi-vibrator, the original transistor circuit was indeed inefficient, I agree with you. The one with MosFets, I estimate, an efficiency of 90% (maybe even higher) and could only be used for small loads. But it was a principle what was at stake, that it could be done.
Where the venture money should be invested in, is in very high voltage MosFets and a thousand of small companies to develop the EEstore concept further. The oil companies nor patent offices cannot thrash all those companies, some will survive. If one can store all those electrons in a LiPO4 sized battery, why not in a capacitor with the approx same size. Provided one can crack the problem of the capacitor, which is, that the electrons are removed from surface of the plates. Bert

 

There are ways and means to keep it in a safe without running foul with the law. Can you explain why it was, when BMW announced the "from water" engine some years ago, that it very quickly disappeared from the earth. So did the supercaps from Siemens. Can you explain it? Bert

 

Ray, it appears that I am not the only one.
http://able2know.org/topic/26695-1
Bert
P.S. Lets assume somebody brings such a product on the market, what will happen to the income of all the gasoline (petrol) stations, oil companies, government incomes on sales of gasoline, diesel, petrol. What would happen to the stock exchanges?

 

There's some pretty bright engineers out there working for the oil companies and other conglomerates that would have turned something up if there was such a thing. Look at what happened with the "cold" fusion fiasco (the 2 goofball scientists were never assasinated by big oil, but only fell to dishonor)- meanwhile every lab, company and government agency fought for a piece of something fake... There would be an instant "gold rush" of competition if any such thing had a valid basis, no way to squash it! The markets would soar on such news of "free" energy.

Companies that bring out prototypes based on hydrogen and other phoney such fuels like water, air, cow farts, etc. are desperate for free advertising, and to create an image that they are the leaders of future technology. That's where the conspiracy is, because they get their 5 minutes of fame and know they will never have to deliver. No telling what the psychology behind fraud inventions is for individuals that have claimed to make a breakthrough....

Back to batteries, I have tested the new B&D nicads to almost twice the capacity of their previous counterparts and their cost is lower than the previous. The NiMH batteries in the Toyota Prius have also been improved, and dropped in price from the generation I versions, judging by the cost of replacement packs. Even the lead based systems are better than they were. These other systems are not going away, but only getting better and cheaper in their niche uses, where Lithium can't compete. I'm not surprised about your bad experience with lithium batteries, this is a complex system with plenty of vulnerabilities... Jeremy follows the endless sphere forum and probably knows the latest status of the different systems...

FWIW category.


Porta

 

Yeah I know Bert, there are millions of nutcases out there on the internet who think it's possible to defy the laws of conservation of energy and thermodynamics, water-powered engines and perpetual motion devices.

I'm not immune to equally wild fantasies, to this day I still believe that there's a hot 18 year-old girl out there who will find me attractive.

 

You want one that will really mess with your head, look up zero point energy. If anyone ever figures out how to harness that the world will change yet again.

 

Bert,

Making a switch mode buck converter is easy - they are everyday items and pretty efficient, maybe 95% or so.

That doesn't address the basic physics of resistive losses at all, though. Just as I said in my last post you will get massive power losses from the resistance in the motor, controller, wiring etc by down-converting and running at high current - it's fundamental physics and not something that can be fixed.

The idea just doesn't have merit for a viable energy storage system for vehicles or boats, much as it might seem attractive to dream that it may have.

When it comes to high voltage switched mode systems, then for anything over about 150V MOSFETs are not the best technical solution, by far. Again there is basic physics involved, which means that as you make the insulation layers on the wafer thicker, in order to handle higher voltages, the on-resistance increases, making the resistive losses greater. This is a fundamental issue with MOSFET topology, which is why they are not used for high voltage, high power switching.

There is already a good, robust, low loss switching device available for high voltage converters, the IGBT. They are used extensively in high power systems and have been for years. Even the Toyota Prius uses IGBT switches in its high power converters. They aren't new, have been around for years and are well-matched to the needs of high voltage, high power motor controllers.
Jeremy

 

O.K. point taken. What I try to say is, one has a cubic foot of lead battery, you get a certain energy out of it and you need maybe 200% energy to digg it out of the ground , to make it, to transport it and to re-charge it.
With Lithium you have one cubic feet of Lithium energy and it cost you 180% to dig it out of the ground, to make it. etc. (or maybe even 300%)
Why not 1 cubic foot of super capacitor, which may only take 160% to dig the materials out of the ground, to use it to half value with IGBT's . i.e. 300 Volt in , 150 Volt out and not 12 Volt - recharge it again, make it 2 cubic feet with lighter materials and one can use it for 40 years and fast re-charge it all the time again. Somewhere in the world there must be somebody with more inovation then us on the net. The same for water. It may cost 500% to take the 100% energy out of the water. But water has energy in it. I don't under estimate possibilities. 100 years ago, if you had asked somebody about a nuclear powerstation. He would glared at you. Bert

 

Citroen calls it "micro hybrid drive" in their current advertising campaign, which I think is total nonsense, but the technology is beautiful.

Instead of a starter motor, there is a somewhat over-sized alternator driven with a toothed belt. In the housing are two unusual parts: a printed circuit board with a drive circuit, including some serious Mosfets and a capacitor array. Most of the power needed for this start/stop system comes from the capacitor.

So it is really happening already, albeit just to restart the engine at the traffic lights!

 

There is not really that much difference between a capacitor and a battery to begin with. Both involve two plats with different charges in an electrolyte of some flavor. Caps are optimized for rapid charge and tend to have greater charge leakage whereas batteries have the opposite.

 

There's a big difference, as batteries use a chemical reaction to store energy, whereas capacitors just use the charge stored on the plates themselves.

In practical terms, it's the chemical energy conversion process in a battery, of whatever type, that eventually fails, leading to loss of capacity. With a capacitor, as Bert has already pointed out, because no chemical reactions are involved their life is, at least in theory, infinite - they shouldn't ever "wear out".

The way this difference shows itself is also in the feature I've already highlighted, the drop in terminal voltage with reducing charge level for a capacitor.

The amount of energy a capacitor can store is set solely by physical limits; the physical area of the plates, the distance between them and the dialectic constant of the insulation between the plates. Capacitors don't use chemical reactions to store energy, they use stored charge, which is literally just a bunch of electrons sat piled up on one plate waiting to flow somewhere as the energy storage method.

For a battery of pretty much any type, capacity is determined by the ability of the electrolyte/plate interface to store chemical energy, or, in the case of lithium cells, the ability of the ion exchange mechanism at the electrode surface to store energy. Both of these are chemical reactions and don't rely on stored charge, in the strictest sense of the term.

Jeremy