CONTROL DEVICE FOR BATTERY OF MARINE VESSEL, CONTROL METHOD THEREFOR, AND MARINE VESSEL

In a control device for a battery of a marine vessel, a first value indicating either a voltage or a power storage amount of a main battery to supply electric power to start the engine is acquired. When the first value that has been acquired is smaller than a first threshold value, at least one of a prohibition of a transition to a motor drive mode in which a propeller is driven by using at least a motor regardless of an operation mode that is designated and a prohibition of charging a load battery is performed, and the engine is caused to rotate to charge the main battery.