Proper battery management, including switching and charging, is essential for safe and reliable operation. The following basic wiring diagrams show how batteries, battery switches, and Automatic Charging Relays are wired together from a simple single battery / single engine configuration to a two engine, one generator, and four battery bank system.. Re: wiring 2 batteries and two engines Agreed the single switch setup probably isn't the best solution and Fox's wiring diagram is another way yours might be set-up. In his diagram the starboard and port engines both have a battery to crank them.. They are also hooked to the accessory circuitry via the disconnect switch.
I assume that since you mention your 1999 Boston Whaler 230 OUTRAGE has a diagram showing two batteries and two switches that the boat was rigged with twin engines. Please mention how many engines the boat has now. The usual two-battery two-engine wiring for Boston Whaler is described in an old article I wrote years ago in REFERENCE. See. Battery Switch Wiring Diagrams Single Engine, Single Battery Diagram. Single Engine, Two Batteries. Switch Position indicates which battery (#1, All, #2) is connected to the engine. Two Engines, Two Batteries, Two Switches. This allows either engine to be started by either battery. Port switch indicates which battery (#1, All, #2) is connected.