Dead battery after sitting on trailer

[Lou C]

Battery switch is a good start. The only thing that should be powered with it OFF is the auto bilge switch/pump. At the beginning of the season it is a good idea to make sure that the alternator is actually charging the batteries and also check for any parasitic draws, with older boats you never know what was added by previous owners.

 

[KM7]

I will look into getting one of these installed

You can do it yourself. Litteraly 4 screws to mount it and then run the battery cables to the switch instead of the positive terminal in the motor. You will need just one more battery cable. See diagram.

There is one drawback with this configuration. If I remove or disconnect battery 1, I will not have power on the boat. I plan on adding a bus bar and run the 2 battery negatives to the bus bar and a 3rd cable from the bus bar to the engine block