Victron Cyrix-ct 12/24V-120A intelligent battery coupler

• Continuous current: 120A
• max. peak current (5 seconds): 180A
• Operating voltage range: 12V / 24V (auto-detection)
• Manufacturer MPN: CYR010120011R

Intelligent battery monitoring to prevent unwanted switching

Some battery couplers (also called voltage-controlled relays or split charge relays) disconnect a battery when a short but high-amperage load occurs. Sometimes a battery coupler also fails to connect a large but discharged battery bank because the DC voltage immediately drops below the threshold value for disconnection after the batteries have been connected.

The software of the Cyrix-ct 12/24 performs more functions than simply connecting and disconnecting based on the battery voltage and with a set time delay. The Cyrix-ct 12/24 monitors the general trend (voltage rising or falling) and only reverses a previous action if the trend has reversed during a certain period of time. The time delay depends on the extent to which the voltage deviates from the trend.

(For battery couplers with multiple switch-on/disconnect profiles, please refer to the Cyrix-i 400.)

Long bolts so that more than one power cable can be connected
Cyrix 12/24-120: 13 mm (M6) Cyrix 12/24-230: 16 mm (M8)

LED status indicator

LED status indicator (Cyrix 12/24 230 only)
LED on: connected LED lights up for 10 seconds: disconnected
LED lights up for 2 seconds: connecting LED flashes every 2 seconds: disconnecting
LED flashes every 0.25 seconds: Alarm (overheating; voltage > 16 V; both batteries < 10 V; one battery < 2 V) (multiply by 2 for 24 V)

Cyrix battery couplers are ideal for replacing isolating diodes. Their main feature is that there is virtually no voltage loss, so the output voltage of the alternators or battery chargers does not need to be increased.

The starter battery takes priority

In a typical setup, the alternator is connected directly to the starter battery. The auxiliary battery and possibly also a bow thruster and other batteries are each connected to the starter battery via Cyrix battery couplers. When a Cyrix detects that the starter battery has reached the connection voltage, it closes to allow parallel charging of the other batteries.

Voltage detection in both directions and power supply from both batteries

The Cyrix measures the voltage of the two connected batteries. It therefore also switches on when, for example, the additional battery is being charged by a battery charger.

The Cyrix-ct 12/24 has a dual power supply. It therefore also switches off if the voltage on one of the batteries is too low to operate the Cyrix.
To prevent unintentional operation during installation or if one of the batteries has been disconnected, the Cyrix-ct 12/24 does not switch off if the voltage at one of the two battery connections is below 2 V (12 V battery) or 4 V (24 V battery).

Parallel connection for emergencies (Start Assist )

The Cyrix can also be switched on via a push button (Cyrix remains in operation for 30 seconds) or via a switch to connect the batteries in parallel manually.
This is particularly useful in an emergency if the starter battery is discharged or damaged.

Scope of delivery:
1x Victron CYR010120011R Cyrix-ct 12/24V-120A battery coupler
1x Operating instructions