What is the typical function of an automotive diode isolator?

The typical function of an automotive diode isolator is to prevent backflow of current. In a vehicle's electrical system, diode isolators are often used to manage multiple batteries, ensuring that while one battery is charging, the other does not discharge back into the charging circuit. This is particularly important in scenarios where auxiliary batteries are used for powering accessories, as it protects the starting battery from being drained by devices powered by the auxiliary battery.

The isolator allows for a one-way flow of current, ensuring that current can flow from the charging source to the batteries but cannot flow back from the batteries to the charging source or to one another. This functionality is crucial in preventing battery drain and preserving the health of all batteries involved in the system.

The other options are not functions of a diode isolator. Boosting voltage is generally achieved using a voltage booster or a DC-DC converter. Regulating fuel flow pertains to fuel management systems and has no relation to electrical components. Measuring battery health is handled by battery monitors or smart battery management systems, not by diode isolators.