Victron Cyrix-i 12/24V 400 A Battery Combiner Battery Isolator Battery Protector

Cyrix-i Intelligent Battery Combiner

The Cyrix battery combiner is a high-performance, microprocessor-controlled relay that automatically connects batteries in parallel when one of them reaches a preset voltage value (indicating that the battery is charging), and disconnects the batteries from each other when the voltage drops below the float voltage value (indicating that one or both batteries are discharging).
Cyrix battery combiners are excellent for replacing isolation diodes. Their main feature is that there is virtually no voltage drop, so the output voltage of AC generators or battery chargers does not have to be increased.

Product features

• maximum continuous current: 400 A
• permissible starting current (1s): 2000 A
• suitable for 12V or 24V systems (automatic detection)
• virtually no voltage drop

New: pioneering battery monitoring prevents unwanted switching operations

Some battery control relays trigger disconnection during short-term high currents. It can also happen that a large but empty battery bank cannot be connected because the voltage drop during connection causes the threshold value for disconnection to be undershot.
The software embedded in the Cyrix-i does not only rely on voltage values and fixed time intervals. Instead, Cyrix-i considers the trend (voltage/time curves) and only intervenes when the trend changes over a certain time interval. The time delay is proportional to the voltage deviation from the trend curve. In addition, four different switching/time curves can be set.

Automatic range selection for 12/24V

Cyrix-i automatically detects the system voltage.

No voltage drop

The Cyrix-i battery control is the alternative to isolation diodes. Since there is virtually no voltage drop, the usual increase in charging voltage at the alternator or charger to compensate for losses is eliminated.

Priority switching for the starter battery

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

Bidirectional voltage measurement and power supply

Cyrix-i measures the voltage values of the connected battery banks. It therefore typically also reacts when the house battery is charged by a charger. The Cyrix-i has a dual power supply. It therefore also works when one of the connected batteries has undervoltage for Cyrix-i operation.
To prevent unwanted switching operations during installation or after disconnecting the battery connection, Cyrix-I will not switch if the voltage value of one of the two battery connections falls below 2V (12V battery), 4V (24V battery) or 8V (48V battery).

Parallel connection in an emergency

The Cyrix-i can also be switched on via a push-button (Cyrix-i then remains on for 30 seconds). There is also a switch for manual parallel connection of the batteries. This is particularly helpful if the starter battery should be empty or damaged in an emergency.

Documents & Downloads

• Datasheet Cyrix-i 400