"Alternators are used in all gas combustion engine automobiles to charge the battery and to power the electrical system when its engine is running."
https://www.apparentlyapparel.com/news/nikola-teslas-wireless-electric-automobile-explained
"Hydrogen is an increasingly popular energy carrier. It can be readily produced from water using renewable electricity"
https://www.cummins.com/news/2022/01/26/how-do-hydrogen-engines-work
"By splitting water by electrolysis and creating hydrogen/oxygen gas, you can replace gasoline."
http://waterpoweredcar.com/
"the BMW directly ignites the hydrogen in its internal combustion engine."
"it injects the hydrogen directly into the car’s air intake manifold (similar to nitrous oxide injection) to be combusted in the engine’s cylinders rather than converting the hydrogen’s energy into electricity to spin electric motors like a fuel cell."
https://www.bmw-tech.org/wiki/BMW_Hydrogen_7