hydrogen fuel cell from 12 volt power
HHO fuel cells are almost as big a con as global warming. Don't waste you time.
The power for those alleged HHO cells come from gasoline as does all energy in a modern gasoline powered car. Keep in mind that an HHO cell is a container of aqueous ionic water with two metal electrodes. A typical car lead acid battery is six containers of aqueous ionic water (sulfuric acid) with two metal electrodes in each container. Have fun spending money on something you already have six of and won't do a bit of good improving your mileage.
HHO is a con, it's been disproved many many times. I have a long post that PROVE that it can NEVER help fuel mileage. Post an edit and I'll re-post it here. The short version is that for order for HHO to work it would have to increase efficiency of your engine by more than 100% which would mean your 100 hp engine would put out 200+ hp. Given what drag racers go to insane extremes to make hp if something as easy as HHO would more than double HP don't you think they would be using it?
The law of conservation of energy says that in a closed system energy is conserved. It is not created or destroyed. But as there are losses due to resistance the efficiency of a machine will always be less than one. (or you will be tapping into an energy source outside of the system.) A car engine gets its energy from the fuel. It produces a lot of heat, some motion and some electricity for accessories. Due to resistance losses there is simply not enough energy in the electrical accessory output to supply power to electrolyze water (again at a loss) that will give enough energy to operate the vehicle. It might be possible to put a solar panel on the roof and get some hydrogen gas with this power but because of efficiency losses when changing energy forms it would probably be more efficient to use this to simply charge the existing battery.
