Guide to Bus Bars for Your Boat

A bus bar is an electrical conductor through which a concentration of power can be distributed to or from several less powerful electrical circuits on a boat. 

Bus bars enable you to connect multiple low voltage circuits (lights, electrical equipment, etc.) to or from the boat’s battery without overloading the connectors. To accomplish this, bus bars must be able to conduct electrical power as efficiently as possible. 

Bus Bar Types

Boat bus bars use either copper or brass as the conductive element. Copper is a single chemical element, whereas brass is an alloy made of the chemical elements copper and zinc.

Copper is incredibly conductive, second only to pure silver in electrical conductivity. As for brass, the proportions of copper and zinc used to make it vary depending upon the type of brass being produced and what it’s used for. Alloying copper with zinc increases its strength, making brass much stronger than copper, but it also reduces the electrical conductivity of brass by comparison.

Copper has a conductive value of 100%, whereas brass has a value of only 28%, which means brass is almost four times less conductive than copper. The conductivity of a metal is determined by its resistance, with resistance being the natural amount the metal opposes the flow of an electrical current through it. So the greater the resistance, the less the conductivity, which is really more important when talking about protective metals such as zinc anodes. 

While some boat owners may swear that copper bus bars are better than brass bus bars, the truth is you’ll probably never notice the difference. Science says copper bus bars have the edge over brass bus bars, but when it comes to buying them, the quality of the product is more important than what it’s actually made of.