Various different power sources have been used on submarines over the years. The ''Hunley'' was powered by its crew turning a crank which was connected to the propeller. [[Gasoline|Petrol]] engines have also been used, but they gave way to [[diesel engine]]s. The petrol or diesel engine drives a [[generator]], which charges a [[Battery (electrical)|battery]], and the battery supplies an [[electric motor]] which propels the submarine. The petrol or diesel engine can only be run when the submarine is on the surface, to recharge the battery. | Various different power sources have been used on submarines over the years. The ''Hunley'' was powered by its crew turning a crank which was connected to the propeller. [[Gasoline|Petrol]] engines have also been used, but they gave way to [[diesel engine]]s. The petrol or diesel engine drives a [[generator]], which charges a [[Battery (electrical)|battery]], and the battery supplies an [[electric motor]] which propels the submarine. The petrol or diesel engine can only be run when the submarine is on the surface, to recharge the battery. |