Battery Setup

[tsubaki]

The normal preferred situation would be only three wires going to each terminal of a single battery. The engine wire (usually a #4 Or #6), the fuse panel main feed (#12 or #10) and a fused bilge supply. Adding an extra battery cuts your chances of low voltage in half if you connect all the negative terminals together then connect the engine wire and fuse panel main wire positives together and to the load terminal of the battery selector switch. Then connect to the battery 1 terminal with a battery and to the battery 2 terminal with the other battery. The fused bilge terminal is only if the boat is to be moored in the water to be connected directly to either one battery. This way the battery switch can be turned to the off position when not being boarded and save battery life and also allow selection between preferred batteries.