Victron Cyrix-i Intelligent Load Relay 12/24V-400A

The cyrix battery coupler is a robust microprocessor-controlled relay that automatically connects batteries in parallel as soon as one of them reaches a pre-set voltage (meaning it is being charged) and disconnects them when the voltage drops below the float level (meaning one or more batteries are discharging). Cyrix battery couplers are an excellent replacement solution for diode separators. Their main characteristic is that they have almost no voltage drop, thus avoiding the need to correct the charging voltages of alternators or battery chargers.

Some Battery Couplers (also called Voltage Controlled Relays, or Auxiliary Load Relays) will disconnect a battery when charging at too high an amperage, albeit for a short time. A battery coupler can also fail to connect a large battery bank that is discharged, because as soon as the batteries are connected, the DC voltage immediately drops below the turn-off value.

The Cyrix will switch off in case of excessive contact temperature, and it will switch on again after cooling down.

Cyrix battery couplers are an excellent replacement solution for diode separators. Their main characteristic is that they have almost no voltage drop, thus avoiding the need to correct the charging voltages of alternators or battery chargers.

In a typical installation, the alternator is directly connected to the starter battery. The service battery and possibly a bow thruster and other batteries are all connected to the starter battery by Cyrix battery couplers. When a Cyrix detects that the starter battery has reached its cut-in voltage, it closes to allow parallel charging of other batteries.

The Cyrix monitors the voltage of the two connected batteries. Therefore, it will also engage when, for example, the service battery is charged by a battery charger.

The Cyrix can also be activated with a push button (the Cyrix remains activated for 30 s) or with a switch to connect the batteries in parallel manually. This can be very useful in an emergency when the starter battery is discharged or damaged.