How to Wire a Marine Battery Isolator

Battery isolators are a great addition to any marine boat since there are electric winches and other high drain devices that severely drain the battery. Battery isolators in boats do not have a manual switch; rather, it is all automatic. It is not recommended that you use a diode battery isolator for your boat. Instead, a hell-raiser battery isolator is suggested so that the majority of the alternator current bypasses the isolation device. The automatic combiner eliminates confusion and reduces risk of alternator damage. Battery isolators seem like a complicated phenomena, but they are rather easy to install.

1. First: Begin installation of battery isolator

   First, there are different setups based on different types of boats and situations. The standard installation is for one battery isolator and two batteries with one engine. You must disconnect the large red or orange wire from the alternator, and attach it to the other end of the starter. Then, run a new eight gauge wire from the alternator to the common on the battery isolator.

2. Second: Continue the installation process

   At this point, check that all wires are kept out of the way of belts, and that everything is clean or capped off. There are two remaining posts on the battery isolator, and you need to use the same gauge wire and route it to each positive end of the batteries. Once you have done this, you are finished with the installation. The last part is to connect the batteries to the engine correctly. You have just installed your marine battery isolator.