MARINE PROPULSION SYSTEM AND MARINE POWER SUPPLY SYSTEM

A marine propulsion system includes a marine propulsion unit, a first battery for a starter of an engine, a second battery for an electric motor, a third battery for at least one of a plurality of devices in or on a marine vessel excluding the starter and the electric motor, and a charge amount acquisition controller configured or programmed to perform a control to acquire a charge amount of at least one of the first battery, the second battery, or the third battery based on a first power supplied from a power source to the first battery, the second battery, and the third battery, and a second power supplied from the first battery, the second battery, and the third battery to devices in or on the marine vessel.