Third battery

[Flbarcase75]

Just purchased a 2003 four winns vista 268. There is a 3rd battery that is on the port side in the back behind the other 2 batteries. I can’t figure out what it goes to.

 

[airshot]

Typically, there is one battery for engine starting ( one for each engine if duals) then a house battery to run onboard electric use. Many folks use two deep cycle house batteries for over nite or large electrical draws like lights and radios and refridgerators. Single or dual engines ??

 

[Flbarcase75]

I have 1 engine. 2 of these batteries are linked to the battery switch. But this one is in the back. I guess tomorrow I have to trace the cables down. Replaced top of the batteries today. They appeared to run the lights. Start the engine, windless, generator, but that battery back there I have no idea

 

[airshot]

Trace the cables, might just be a spare, hard to say.

 

[alldodge]

I have 1 engine. 2 of these batteries are linked to the battery switch. But this one is in the back. I guess tomorrow I have to trace the cables down. Replaced top of the batteries today. They appeared to run the lights. Start the engine, windless, generator, but that battery back there I have no idea

Welcome
A boat with a Windless would normally require and additional Bat and windless would run off the House Bat. Having a Generator it would have one attached to start it which could also be used as the House