Batteries are at the heart of the electrical systems found on any boat or vehicle. 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. For more detailed wiring guidelines please consult a qualified marine electrician or one of the many books available on the subject.
The diagrams below are intended for reference only. Consult an ABYC certified marine electrical professional for system design and circuit protection.
Switches a single battery to a single load group
ON-OFF Battery Switch
Saves battery power for starting
1 ON-OFF Battery Switch
1 Low Voltage Disconnect
Switches isolated battery banks to all loads or combines battery banks to all loads
1 Selector Battery Switch
1 Automatic Charging Relay
Simultaneously switches two isolated battery banks or combines battery banks to all loads.
1 Dual Circuit Plus™ Battery Switch
1 Automatic Charging Relay
Can isolate a failed battery
3 ON-OFF Battery Switches
1 Automatic Charging Relay
House battery is shared with one engine. One engine battery is in reserve.
2 Selector Battery Switches
1 Automatic Charging Relay
Engines share one battery. House battery is in reserve.
1 Dual Circuit Plus™ Battery Switch
1 Automatic Charging Relay
Can isolate a failed battery.
3 ON-OFF Battery Switches1 Automatic Charging Relay
Simple Operation - Can parallel batteries for extra starting power.
2 Dual Circuit Plus Battery Switches
2 Automatic Charging Relays
Can isolate any battery source from any batteries.
3 Selector Battery Switches
2 Automatic Charging Relays
Can parallel batteries for extra starting power.
3 Dual Circuit Plus Battery Switches
3 Automatic Charging Relays
Can isolate any battery source from any batteries.
4 Selector Battery Switches
3 Automatic Charging Relays
