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#11
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#12
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Orval Fairbairn wrote:
In article , (Edward A. Falk) wrote: In article , wrote: A tank full of gas doesn't get hot because it is being used but batteries do. A friend of mine pointed out that although gasoline needs to have oxygen added before it can burn, a battery already contains everything it needs to explode. I really, really want to see electric batteries come of age, but gasoline has set the bar very high in terms of safety and energy density. This feature of batteries also explains why they will NEVER compete with air/fuel engines! You have to carry a complete supply of BOTH chemicals required to make them work, rather than just one (fuel). Actually that's not strictly true - a class of batteries called fuel cells could (actually already can) utilize the oxygen in air. Instead of generating heat when the chemical reaction occurs, the released energy can be converted mostly to electrical power. Ironically, the fuel for fuel cell batteries that doesn't require any new costly infrastructure is gasoline. Some work has been done on gasoline fuel cells; so far as I can see the advantages over heat engines are that they theoretically can be mechanically simpler and operate at a higher efficiency. |
#14
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Jim Logajan wrote:
Orval Fairbairn wrote: In article , (Edward A. Falk) wrote: In article , wrote: A tank full of gas doesn't get hot because it is being used but batteries do. A friend of mine pointed out that although gasoline needs to have oxygen added before it can burn, a battery already contains everything it needs to explode. I really, really want to see electric batteries come of age, but gasoline has set the bar very high in terms of safety and energy density. This feature of batteries also explains why they will NEVER compete with air/fuel engines! You have to carry a complete supply of BOTH chemicals required to make them work, rather than just one (fuel). Actually that's not strictly true - a class of batteries called fuel cells could (actually already can) utilize the oxygen in air. Instead of generating heat when the chemical reaction occurs, the released energy can be converted mostly to electrical power. Ironically, the fuel for fuel cell batteries that doesn't require any new costly infrastructure is gasoline. Some work has been done on gasoline fuel cells; so far as I can see the advantages over heat engines are that they theoretically can be mechanically simpler and operate at a higher efficiency. Mechanically simpler doesn't mean a whole lot since the invention of NC machining and the realizable efficiency of a fuel cell in a vehicle isn't that much better than that of a modern piston engine. If the world actually ever ran out of oil as the chicken little's predict, fuel cells run on natural gas could be a practical alternative, but then again so would a conventional piston engine run on natural gas. All of which is a bit moot as the Obama administration cut off funding for vehicle fuel cells in favor of batteries. -- Jim Pennino Remove .spam.sux to reply. |
#15
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On Nov 2, 12:56*am, wrote:
Jim Logajan wrote: Orval Fairbairn wrote: In article , (Edward A. Falk) wrote: In article , wrote: A tank full of gas doesn't get hot because it is being used but batteries do. A friend of mine pointed out that although gasoline needs to have oxygen added before it can burn, a battery already contains everything it needs to explode. I really, really want to see electric batteries come of age, but gasoline has set the bar very high in terms of safety and energy density. This feature of batteries also explains why they will NEVER compete with air/fuel engines! You have to carry a complete supply of BOTH chemicals required to make them work, rather than just one (fuel). Actually that's not strictly true - a class of batteries called fuel cells could (actually already can) utilize the oxygen in air. Instead of generating heat when the chemical reaction occurs, the released energy can be converted mostly to electrical power. Ironically, the fuel for fuel cell batteries that doesn't require any new costly infrastructure is gasoline. Some work has been done on gasoline fuel cells; so far as I can see the advantages over heat engines are that they theoretically can be mechanically simpler and operate at a higher efficiency. Mechanically simpler doesn't mean a whole lot since the invention of NC machining and the realizable efficiency of a fuel cell in a vehicle isn't that much better than that of a modern piston engine. If the world actually ever ran out of oil as the chicken little's predict, fuel cells run on natural gas could be a practical alternative, but then again so would a conventional piston engine run on natural gas. All of which is a bit moot as the Obama administration cut off funding for vehicle fuel cells in favor of batteries. -- Jim Pennino Remove .spam.sux to reply. If there was profit on the horizon it would not take gvmt money, of course. Anyone waiting for battery operated GA airplanes before getting his or her certificate is apt to wait a long time. I was about to suggest someone has his head in the clouds, but that could start a different thread/ |
#16
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a wrote:
If there was profit on the horizon it would not take gvmt money, of course. True. However, there are many very profitable technologies developed on the tax payer dime that have become exceedingly profitable and were well beyond anyone's horizon. This little internet thing being one of them. -- Frank Stutzman Bonanza N494B "Hula Girl" Boise, ID |
#17
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![]() "Jim Logajan" wrote Actually that's not strictly true - a class of batteries called fuel cells could (actually already can) utilize the oxygen in air. A fuel cell is about as much of a battery as a Honda Generator. A fuel cell is an electrical generating device. You put fuel and an oxidizer in and you get power and water out. They store no energy. -- Jim in NC |
#18
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"Morgans" wrote:
"Jim Logajan" wrote Actually that's not strictly true - a class of batteries called fuel cells could (actually already can) utilize the oxygen in air. A fuel cell is about as much of a battery as a Honda Generator. My 5th edition copy of "Physical Chemistry" by Peter Atkins states "A fuel cell operates like a conventional galvanic cell with the exception that the reactants are supplied from outside rather than forming an integral part of its construction." So from a chemistry standpoint they are batteries. The Honda Generator is a heat engine that converts the reactants first to heat, then to mechanical motion, and finally to electrical current. A fuel cell is an electrical generating device. You put fuel and an oxidizer in and you get power and water out. They store no energy. The atmosphere is a handy place to store part of the reactants. But there generally isn't any need to make an earth-bound fuel cell fully reversable and self-contained like other batteries, but it has been done. |
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