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

Cyrix-i intelligent battery isolator

The cyrix battery isolator is a high-performance microprocessor-controlled relay that automatically connects batteries in parallel when one of them reaches a preset voltage level (indicating that the battery is being charged) and disconnects the batteries again when the voltage drops below the float voltage (indicating that one or both batteries are currently being discharged.
cyrix battery isolators are ideally suited to replace isolation diodes. Their main feature is that there is practically no voltage loss, so the output voltage of the alternators or battery chargers does not need to be increased.

Product features

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

New: advanced battery monitoring prevents unwanted switching

In some battery control relays, short-term high currents trigger disconnection. It can also happen that a large but empty battery bank cannot be connected because the voltage drop when connecting falls below the switching-off threshold.
The software stored in the Cyrix-i does not only refer to voltage values and fixed time intervals. Rather, Cyrix-i takes the trend (voltage/time – curves) into account 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 applied system voltage.

No voltage loss

The Cyrix-i battery control is the alternative to isolation diodes. Since there is practically no voltage loss, the increase in charging voltage at the alternator or charger, which is otherwise customary to compensate for loss, is not required.

Priority connection 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 corresponding 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 also typically reacts when the onboard battery is being charged by a charger. The Cyrix-i has a dual power supply. It therefore also works when one of the connected batteries has insufficient voltage for Cyrix-i operation.
To prevent unwanted switching during installation or after loosening 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 an emergency

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