Victron Cyrix-i 24/48V 400A Battery Coupler Isolator Relay Battery Protection

Cyrix-i intelligent 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 value (indicating that the battery is charging) and that separates the batteries again when the voltage drops below the float voltage value (indicating that one or both batteries are discharging).
cyrix battery couplers are ideally suited to replacing isolating diodes. Their main feature is that there is virtually no voltage loss, so there's no need to increase the output voltage of the alternators or battery chargers.

Product features

• maximum continuous current: 400 A
• permissible starting current (1s): 2000 A
• suitable for 24 V or 48 V systems (automatic detection)
• virtually no voltage loss

New: pioneering battery monitoring prevents unwanted switching operations

Some battery control relays trigger disconnections when exposed to high currents for a short time. It may also happen that a large but empty battery group cannot be connected because the voltage drop during connection causes the voltage to fall below the disconnection threshold.
The software embedded in the Cyrix-i doesn't just refer to voltage values ​​and fixed time intervals. Rather, Cyrix-i considers the trend (voltage/time curves) and only intervenes when the trend changes over a specific time interval. The time delay is proportional to the voltage deviation from the trend. Additionally, four different switching/time curves can be configured.

Automatic range selection at 12/24V

Cyrix-i automatically detects the applied system voltage.

No voltage loss

The Cyrix-i battery controller is the alternative to diode isolators. Since there is virtually no voltage loss, there is no need to increase the charging voltage at the alternator or charger, which is otherwise required to compensate for losses.

Priority circuit for the starter battery

Typically, the alternator is connected directly to the starter battery. The onboard battery, possibly the bow thruster battery, and others are connected via Cyrix-i devices. Only when the starter battery has reached the required voltage does Cyrix-i connect the other batteries for parallel charging.

Bidirectional voltage measurement and power supply

The Cyrix-i measures the voltage values ​​of the connected battery groups. Therefore, it typically responds even when the vehicle's electrical system battery is being charged by a charger. The Cyrix-i has a dual power supply, so it will continue to operate even if one of the connected batteries has too little voltage for the Cyrix-i to operate.
To avoid unwanted switching during installation or after disconnecting the battery connection, Cyrix-I will not switch if the voltage value of one of the two battery connections drops to less than 4V (24V battery) or 8V (48V battery).

Parallel connection in case of emergency

The Cyrix-i can also be turned on using a push-button switch (which then stays on for 30 seconds). There's also a switch for manually connecting the batteries in parallel. This is especially useful if the starter battery is dead or damaged in an emergency.