Advanced 400A Battery Combining for 24V and 48V Systems

The Victron Cyrix-i is a heavy-duty, microprocessor-controlled battery combiner designed to safely and efficiently manage multi-battery configurations. Ideal for marine vessels, large off-grid power setups, and commercial vehicles, this robust 400A relay automatically connects batteries in parallel when one has reached a preset charge voltage, and disconnects them when the voltage drops below the float level.

Unlike traditional diode isolators, the Cyrix-i introduces virtually no voltage drop. This critical efficiency eliminates the need to increase the output voltage of alternators or battery chargers, ensuring maximum power delivery. The unit automatically detects either 24V or 48V system voltages, making it a highly versatile component for demanding electrical architectures.

Intelligent Trend-Based Monitoring

Standard battery combiners often struggle with short, high-current loads, disconnecting batteries prematurely if the system voltage dips temporarily. Conversely, they might fail to connect a heavily discharged battery bank because the sudden inrush current instantly pulls the voltage below the disengage threshold. The Cyrix-i solves these issues using intelligent software that monitors general voltage trends rather than reacting to sudden spikes or drops. It will only reverse a switching action if a voltage trend has reversed over a specified time period, which dynamically adjusts based on the severity of the voltage deviation. Installers can also select from four distinct switch timing profiles to suit specific system parameters.

Bidirectional Sensing and Priority Charging

In typical setups, the alternator connects directly to the starter battery. The auxiliary battery, along with heavy loads like bow thrusters, connects to the starter battery via the Cyrix combiner. The system prioritises the starter battery, only engaging parallel charging for auxiliary banks once the primary battery is adequately charged.

Featuring bidirectional voltage sensing, the unit also engages if the auxiliary battery receives a charge from an independent source, such as a solar array or mains battery charger. A dual power supply ensures the internal relay remains operational even if one battery's voltage drops significantly. To prevent unexpected activation during maintenance, fail-safes prevent engagement if connection voltages fall below critical levels (below 4V for 24V systems, or 8V for 48V systems).

Built for Emergency Preparedness

For critical situations where a starter battery is heavily depleted or damaged, the system includes an emergency parallel connection feature. This start assist function can be triggered manually via a push button or remote switch, locking the relay closed for 30 seconds to allow engine starting directly from the house or auxiliary battery bank.

Hardware Built for Professional Installations

The physical design features heavy-duty metal studs to securely accommodate large gauge battery cables, sustaining optimal current flow under peak 400A loads. A front control connector allows for easy integration of the start assist trigger, while an integrated multi-colour status LED provides clear operational monitoring. Side-mounted auxiliary micro switch contacts are also included for remote status tracking.

Key Features

• Auto-ranging capability detects 24V and 48V system voltages automatically
• Zero voltage loss design outperforms traditional diode isolators
• Intelligent trend-based monitoring prevents unwanted nuisance switching
• Bidirectional sensing allows for charging and voltage detection from either connected battery
• Emergency start assist function enables manual parallel connection for engine starting
• Four selectable switch timing profiles for tailored system integration
• Heavy-duty terminals and an integrated mounting bracket ensure a secure, robust installation

Complete Your Power System

Ensure your auxiliary and starter batteries are always properly managed and ready for heavy loads. Add the Victron Cyrix-i 400A Intelligent Battery Combiner to your 24V or 48V electrical system today to experience seamless, high-efficiency power distribution.