Mastervolt Battery Mate 120-Amp 3-Bank IG Isolator

The Mastervolt Battery Mate 1603 IG Isolator distributes 120A of charging across multiple banks using electronic MOSFET switching, DIN rail mounted.

One hundred and twenty amps is the smaller Battery Mate, suiting a standard recreational alternator rather than a high-output one. Where the alternator exceeds that, the 200A version is required. An isolator working beyond its rating heats up and eventually fails, taking the charging path with it.

The electronic MOSFET design minimizes the voltage loss a conventional diode isolator introduces. That loss is why older diode-isolated systems chronically undercharge, and it is invisible unless voltage is measured at the battery rather than the alternator.

It distributes alternator or charger current to multiple banks without manual battery selection. An additional IG connection supports alternators needing external excitation or voltage sensing, electronic compensation maintains correct voltage as conditions change, and DIN rail mounting suits panel installation. Explore more battery charging accessories.

• 120A, for a standard recreational alternator
• The 200A version covers high-output alternators
• MOSFET design avoids the diode isolator's voltage loss
• That loss is why older systems undercharge