My roommate here insists that he saw a show about fuel cell cars, which told him that new ones can be initially charged with electricity, and then the fuel cell can both power the car and disassociate more water. We both are not sure how fuel cell cars work, but he insists that the only continuing fuel for these things is more water.
I say that if you start with X Joules, then you will have X - 1day Joules, and then X - 2days Joules, and you’re going to have to put in some VERY reactive stuff to get yourself back to X. I know that water is essentially the ashes of hydrogen burning, and all I can think of as the reason to bother disassociating water is to store the potential energy and eventually put it back together again at the right time to put the liberated energy to productive use.
His explanation smacks very much of a perpetual motion machine to me.
Please tell us how a fuel cell car would work in basic theory, and what would be needed to keep it running for months.
This Howstuffworks article should explain all the basics. Simply put, a fuel cell is a device that is powered by hydrogen and oxygen and outputs electrical power. Water is a by-product, not the fuel. So a fuel cell car would have hydrogen tanks which need to be filled regularly.
And what your friend is describing is a perpetual motion machine, which violates the laws of physics as we know them. Whenever you hear a claim that some device produces more energy than it consumes, your BS antennae should start quivering.
My only real question was how these things work, and if there could in ANY way be a need for more water later. I knew that water is extremely UNenergetic, so it didn’t make sense on many levels.
What it could be is that you fill up a tank with water and then you plug it into a power socket over night. The car gets the power from the socket to convert the water to H and O. Its easier to fill a car with tap water and electricity than to get specialised hydrogen canisters.