Ultracapacitors (current status of eer, etc.)

The September 2004 issue of the SAE magazine "Automotive Engineering International" has an interesting article on pages 46 to 53 titled
"Ultracapacitors charge ahead" which discusses the use of these components for energy storage in vehicles.
It mentions that most current roles for these devices are as backup for "smart box" safety devices if batteries fail. Low voltage (1 to 3V per cell remains a challenge. Maxwell Technologies has a D-cell sized 2.5V Boostcap which has a 350 farad capacity.
Pittsburgh Pete
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snipped-for-privacy@hotmail.com (Pittsburgh Pete) wrote in message

Ultra-caps are interesting devices for short term energy storage applications because of their ability for rapid charging and discharging (like break energy recovery). Ultra-caps still can't hold a candle to a lead acid battery for watt hours to weight. Gasolene or Diesel gives MUCH more power per weight than even the best battery design. Hydrogen combustion would have the best power per weight of all chemicals, if it weren't the nasty fact that it's a gas at STP. H2 fuel containers are often heavier than the consumeable itself. H2 is just too volumous, even as a liquid. This translates into huge containers with high tolerances and cryogenic handling. It's a rube goldberge imo. H2 based fuel cells are a techno dead end. Methal alchahol is interesting, I'm open minded about it.
As an order of energy storage, as I know it it follows like this from weakest to strongest in terms of power to weight:
1. inductance 2. capacitance 3. flywheel 4. lead acid battery 5. nickel metal hydride battery 6. lithium hydride battery 7. gasolene combustion 8. kerosine combustion 9. Diesel combustion 10. RTG 11. nuclear fusion 12. nuclear fission 13. matter anti-matter annihilation
capacitance is low on my list. If you can point out a flaw in my listing order, please argue. Thanks
-Scott
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I'm not sure the ordering of 11/12 is in error, but I am questioning it. While I'd be willing to be convinced that hydrogen fusion in classic yellow dwarf stars is perhaps lower power to weight (or energy to mass) than is uranium fission, I suspect that heavier light-element fusion in massive stars (after hydrogen was used up but prior to supernova-ing) under the more extreme pressure-temperature conditions may be otherwise.
'Course, it is rather an academic question at present.
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You were right to question. I assumed that because uranium fission yealds more energy per individual event than a typical fusion event it ought to beat fusion's power to weight (I overlooked the MeV per nucleon part of it).
I found this link helpful http://www.physlink.com/Education/AskExperts/ae534.cfm
-Scott
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aSkeptic wrote:

0. Gravity (weak). 0.1 Rubber bands. 0.2. Gas pressure. .....
12.95 Gravity (strong).
Cheers,
Phil Hobbs
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The Toyota impulse uses ultra capacitors to supplement the gasoline engine of a hybrid vehicle. It can go from 0 to sixty MPH in 3 seconds. Its' used to move the vehicle not just to back up battery power.

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