ProMariner ProIsoCharge 120A 3-Battery Isolator

Description

The ProMariner ProIsoCharge 120 1•3 is a digitally controlled 12V alternator power-distribution system designed to charge three battery banks from a single alternator while protecting the engine-start battery. Rather than relying on a traditional diode isolator or a collection of separate voltage-sensitive relays, ProIsoCharge actively manages where alternator output is sent according to the condition and demand of the connected banks.

The system is rated for up to 120 amps and uses zero-voltage-loss isolation, avoiding the approximately 0.6V drop commonly associated with traditional diode-based isolators. Its intelligent charging software can take fully charged batteries offline and give priority to a bank that is under load or more deeply discharged, helping shorten charge times and make better use of available alternator output. The design also keeps the engine battery health prioritized so starting reserve is protected.

Real-time LEDs indicate alternator power and battery-bank charging status. Dedicated fault indications cover high or low alternator output, over-voltage protection events, and high-voltage conditions on connected banks that may also be tied to other charging sources. Ignition-controlled Distributed On Demand operation activates battery-bank management only when ignition power is present.

For alternators equipped with advanced external regulation, a remote-sense connection supports more precise regulator control. The modular design includes terminal-stud insulator boots and a protective snap-on safety cover to simplify installation and improve protection around high-current connections.

The ProIsoCharge 120 1•3 is ignition protected and rated IP66 for resistance to water exposure. It is a strong fit for cruising boats with separate start, house, and accessory banks that need intelligent charging from one alternator without sacrificing voltage through a conventional diode isolator. See what else we carry in battery isolators & charging relays.