ARCO Marine BI-1203-3A Battery Isolator - 120A - 1 Alternator, 3 Battery [BI-1203-3A]

The Arco Marine BI-1203-3A is a top - notch inboard/outboard battery isolator. It can manage 1 alternator, 3 batteries, with a maximum capacity of 120A. It's suitable for 10 to 350 - amp alternators in 12, 24, or 32 - volt negative ground systems and comes with an exciter terminal. Key features include: it allows current to flow in one direction only, so you don't have to worry about a higher - charged battery discharging into a lower - charged one. Both batteries get charged automatically according to their needs when the engine runs. When used with selector switches, there's no need to change switch positions for charging both batteries. The isolator proportions the alternator's output to the batteries as required. Note: It can't be used on 12 - volt charging systems with 24 - volt trolling motors or newer outboard engines with rectifier - regulator charging systems. This product can't be returned to the original purchase point. Contact the manufacturer directly for issues. There's also a Quick Guide (pdf) available.

Using the Arco Marine BI - 1203 - 3A battery isolator is easy. First, make sure your system is a 12, 24, or 32 - volt negative ground system with 10 to 350 - amp alternators. Connect the alternator and the three batteries as described in the manual. Once the engine starts running, the isolator will automatically charge both batteries according to their needs. You don't need to adjust the selector switch position if you're using one. When it comes to maintenance, keep an eye on the electrical connections to ensure they are tight and free of corrosion. And remember, don't use this isolator on 12 - volt charging systems with 24 - volt trolling motors or newer outboard engines with rectifier - regulator charging systems. If you have any problems, contact the manufacturer directly instead of returning it to the original purchase point.