ProMariner ProIsoCharge 120A 3-Battery Isolator

The ProMariner ProIsoCharge 120 1-3 is a digitally controlled 12V isolator charging three banks from one alternator, rated 120 amps.

Zero-voltage-loss isolation is the significant difference from a traditional diode isolator, which drops around 0.6 volts. That drop means the banks never see the full charging voltage, so they sit permanently undercharged. Removing it is worth more than any other feature here.

Intelligent charging software manages distribution between the banks rather than simply splitting whatever arrives. That lets a depleted house bank take priority while the starting battery, which is nearly full anyway, receives what it needs and no more.

Protecting the engine-start battery is stated as a design intent rather than a side effect. A hundred and twenty amps is the alternator capacity it handles, and it should exceed what the alternator actually produces. Explore more battery isolators and charging relays.

• Zero voltage loss against a diode isolator's 0.6V
• That drop leaves banks permanently undercharged
• Software distributes rather than simply splitting
• A depleted house bank takes priority