Victron Cyrix-ct 12/24V 120A Battery Combiner Relay Battery Protector

Cyrix Battery Combiner 120A

The Cyrix battery combiner is a high-performance microprocessor-controlled relay that automatically connects batteries in parallel when one of them has reached a predefined voltage value (indicating that the battery is being charged) and disconnects the batteries from each other again when the voltage drops below the float voltage value (indicating that one or both batteries are currently being discharged).
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 the alternators or battery chargers does not need to be increased.

Product Features

• maximum continuous current: 120 A
• permissible starting current (5s): 180 A
• suitable for 12 V or 24 V systems (automatic detection)
• virtually no voltage drop
• no D+ signal required: The Cyrix battery combiner switches depending on the battery voltage
• Battery temperature protection: In case of high overload, the battery is automatically disconnected

Intelligent battery monitoring to prevent unwanted switching

Some battery combiners (also called voltage-controlled relays or split charge relays) disconnect a battery when a short but high-amperage load occurs. Sometimes a battery combiner also does not connect a large but discharged battery bank because the DC voltage immediately drops below the disconnection threshold after the batteries have been connected. The software of the Cyrix-ct 12/24 performs more functions than simply connecting and disconnecting based on battery voltage and with a fixed time delay.
The Cyrix-ct 12/24 observes the general trend (voltage rising or falling) and only reverses a previous action if a trend has reversed during a certain period. The time delay depends on how much the voltage deviates from the trend.

No voltage drop

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 the alternators or battery chargers does not need to be increased.

Two-way voltage sensing and power supply from both batteries

The Cyrix measures the voltage of both connected batteries. It therefore also switches on if, for example, the auxiliary battery is being charged by a battery charger. The Cyrix-ct 12/24 has a dual power supply.
It therefore also closes if the voltage at one of the batteries is too low to operate the Cyrix.
To avoid unintentional 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).

Overheat protection (e.g. due to prolonged overload)

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

The Cyrix can also be switched on via a push button (Cyrix remains active 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.

Technical Information

Documents & Downloads

• Datasheet Cyrix-ct