Three CFA units from Langwarrin and Baxter were paged to the incident at 2.08pm after a neighbour dialled Triple Zero (000).
The eight metre cabin cruiser boat was parked on the nature strip of a property and was emitting heavy smoke when crews arrived.
Langwarrin Firefighter Craig Aiton said two members from Langwarrin and two from Baxter utilised breathing apparatus and made access to extinguish the fire.
“The 12-volt battery inside the boat was being charged by battery charger inside the cabin,” he said.
“The combination of the battery charger sitting on a seat cushion and limited ventilation caused the battery charger to overheat and set fire to the surrounding materials.
“The cabin of the boat contained bedding, pillows and life jackets which were impacted by the fire and added to the intensity of the fire and smoke.
Firefighters were able to contain the fire to the inside of the boat.
“Due to the quick arrival of CFA firefighters the damage was limited to the front cabin area and the contents,” FF Aiton said.