Victron Cyrix-ct 12/24V 230A battery coupler isolating relay battery protection

Cyrix battery coupler

The cyrix battery coupler is a high performance microprocessor controlled relay that automatically connects batteries in parallel when one of them has reached a predetermined voltage level (indicating that the battery is charging) and that separates the batteries again when the voltage drops below the float voltage level (indicating that one or both batteries are discharging). cyrix battery couplers are ideal for replacing isolating diodes.
Their main feature is that there is virtually no voltage loss, so there is no need to increase the output voltage of the alternators or battery chargers.

Product features

• maximum continuous current: 230 A
• permissible starting current (5s): 500 A
• suitable for 12V or 24 V systems (automatic detection)
• practically no voltage loss
• no D+ signal required: The Cyrix battery coupler switches depending on the battery voltage
• Battery temperature protection: In case of high overload, the battery is automatically disconnected

Intelligent battery monitoring to avoid unwanted switching

Some battery couplers (also called voltage controlled relays or split charge relays) will disconnect a battery when a short but high-amperage load is encountered. Sometimes a battery coupler will not connect a large but discharged battery bank because the DC voltage immediately drops below the disconnect threshold after the batteries are connected. The Cyrix-ct 12/24 software does more than simply connect and disconnect based on battery voltage and with a set time delay.
The Cyrix-ct 12/24 observes the general trend (voltage increasing or decreasing) and reverses a previous action only if a trend has reversed during a certain period of time. The time delay depends on how far the voltage deviates from the trend.

No voltage loss

Cyrix battery couplers are ideal for replacing isolating diodes.
Their main feature is that there is virtually no voltage loss, so there is no need to increase the output voltage of the alternators or battery chargers.

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 shuts off if the voltage on one of the batteries is too low to operate the Cyrix.
To avoid unintended operation during installation or if one of the batteries has been disconnected, the Cyrix-ct 12/24 will not close if the voltage at either battery terminal is below 2 V (12 V battery) or 4 V (24 V battery).

Protection against overheating (e.g. due to prolonged overload)

The Cyrix disconnects when the contact temperature is too high and reconnects after the temperature has dropped.

Parallel connection for emergency use (Start Assist)

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