WARN 28022 Dual Battery Isolator for use with alternators up to 120 amp

Because of the increased demands a winch and other accessories place on the DC power supply, many vehicles have multiple batteries-one to start the engine and another to power accessories. The WARN 28022 battery isolator prevents the problem of multi-battery drain, so no matter how drained your accessory battery becomes, it will never drain power from the battery you're depending on to start your engine.