Mastervolt Battery Isolator BI-1202S

The Mastervolt Battery Isolator BI-1202S provides means of tailoring the supply of simultaneous charge current to multiple battery banks from an alternator or battery charger while still maintaining separate battery bank isolation. - meaning, for example, you can simultaneously charge the engine start battery and leisure battery without one battery drawing power directly out of the other battery (i.e. a battery isolator prevents current flow between the battery banks themselves).

As you often find two or more batteries/battery banks operating electrical systems onboard your boat (i.e. engine starter battery and leisure batteries), which maybe divided into multiple systems to prevent one battery drawing power from the other (i.e. as the least full battery will try to charge itself back to strength from the more charged battery), you will also need to separate the charge to these batteries by using a battery isolator.

By using a battery isolator you are dividing the charge (the charge becomes isolated) and preventing a drained battery (i.e. the starter battery that has just started the engine) from draining the leisure battery (i.e. the battery providing power to the lights for example) which also helps to keep the battery at optimal level for usage where you need it.

The Mastervolt BI-1202S Battery Isolator features two battery outlets and can handle a maximum of 120A output from a alternator and a maximum of 80A output from a battery charger whilst offering protection via a compensation diode which compensates for the voltage drop over the diodes (0.6v).

A marine battery isolator also provides more protection from potentially serious situations as the distribution of charge current to the batteries take place with minimum energy loss.

Mastervolt Battery Isolator BI-1202S Specifications