The water fuel cell, named by American Stanley Meyer, is a device claimed to convert water into its component elements, hydrogen and oxygen (water electrolysis – 2H2O → 2H2 + O2), using less energy than that present in the elements’ bond itself. The water fuel cell could reportedly produce several times more energy than it consumes. In practice, an engine would be connected to a cell and, through the combustion process, convert the hydrogen back into water (2H2 + O2 → 2H2O). At least one car prototype reportedly powered by a water fuel cell has been assembled.
Meyer’s claims about the Water Fuel Cell and the car that it powered were found to be fraudulent by a Ohio court in 1996. Similar devices have been promoted by others; see Water-fuelled car.
The operation of the fuel cell, as described by Meyer, would violate the first law of thermodynamics. Energy would not be conserved, making the device a type of perpetual motion machine. In other words, a car running on a water fuel cell could achieve perpetual motion simply by venting the exhaust pipe (containing water vapour) into the fuel tank (containing water). As a result, the cell and its actual operation (when not met with outright dismissal) is seen with much skepticism from established scientists.
Stanley Meyer was granted patents in the United States and abroad starting in 1989. (However, patents do not imply a peer review has taken place, nor that the findings have been confirmed and reproduced by independent parties.)
The fuel cell consists of stainless steel plates arranged as a capacitor, with pure water acting as the dielectric. A rising staircase of direct current pulses is sent through the plates at roughly 42 kHz, which is claimed to play a role in the water molecules breaking apart with less directly applied energy than is required by standard electrolysis. The mechanism of this reaction is undocumented.
Meyer presented his fuel cell device to Professor Michael Laughton, Dean of Engineering at Queen Mary College, London, Admiral Sir Anthony Griffin, a former controller of the British Navy, and Dr. Keith Hindley, a UK research chemist. According to the witnesses, the Meyer cell remained remarkably cold, even after hours of gas production as his system appeared to operate on much smaller current than conventional electrolysis would require. The witnesses also stated:
After hours of discussion between ourselves, we concluded that Stan Meyer did appear to have discovered an entirely new method for splitting water which showed few of the characteristics of classical electrolysis. Confirmation that his devices actually do work come from his collection of granted US patents on various parts of the WFC system. Since they were granted under Section 101 by the US Patent Office, the hardware involved in the patents has been examined experimentally by US Patent Office experts and their seconded experts and all the claims have been established.
Its name not withstanding, the water fuel cell is not a true fuel cell. It would be an electrolytic cell, as it is claimed to produce hydrogen from water and not the opposite. 
Meyer’s water-fueled car
It Runs on Water is a video with Stanley Meyer demonstrating the water fuel cell in a car. Meyer claimed that he could run a 1.6 liter Volkswagen dune buggy on water instead of gasoline. He replaced the spark plugs with “injectors” to spray a fine mist into the engine cylinders, which he claimed were electrified at a resonant frequency. The fuel cell would split water into hydrogen and oxygen gas, which would be combusted back into water vapor in a conventional hydrogen engine to produce net energy. Meyer demonstrated his vehicle for his city’s local station Action 6 News and estimated that only 83 liters (22 US gallons) of water was required to travel from Los Angeles to New York.
In 1996, inventor Stanley Meyer was sued by investors to whom he had sold dealerships, offering the right to do business in Water Fuel Cell technology. According to The Times, Meyer claimed in court that his invention “opened the way for a car which would ‘run on water’, powered simply by a car battery.” The car would even run perpetually without fuel since the energy needed to continue the “fracturing” was low enough for the engine’s dynamo to recharge the car’s battery. His car was due to be examined by the expert witness Michael Laughton, Professor of Electrical Engineering at Queen Mary, University of London and Fellow of the Royal Academy of Engineering. However Meyer made what Professor Laughton considered a “lame excuse” on the days of examination and did not allow the test to proceed. The Water Fuel Cell on the other hand, was examined by three expert witnesses in court who found that there “was nothing revolutionary about the cell at all and that it was simply using conventional electrolysis”.
On the basis of the evidence the court found Meyer guilty of “gross and egregious fraud” and ordered to repay the investors their $25,000.
Stanley Meyer died at the age of 57 after eating at a restaurant on 21 March 1998. An autopsy report by Franklin County coroner William R. Adrion showed the cause of death to be a cerebral aneurysm. Conspiracy theories persist, however, that he was poisoned, and that oil companies and the United States government were involved in his death.