Victron Cyrix-i 400A Battery Combiner

The Victron Cyrix-i 400A is the definitive high-performance smart relay designed for the most demanding DC power architectures. With a massive 400A continuous current rating and the capability to handle 2000A peak surges, this microprocessor-controlled combiner is the ultimate solution for heavy commercial vehicles, high-output marine systems, and large-scale off-grid power installations. It effectively replaces outdated, loss-prone diode isolators, ensuring your charging system operates at maximum efficiency.

Built for resilience, the Cyrix-i 400A utilizes a direct physical relay connection, resulting in virtually zero voltage drop during charging. Its intelligent bidirectional sensing and advanced trend-monitoring software ensure reliable, stable operation, even in systems with fluctuating loads. Whether you are managing multiple high-capacity battery banks or integrating powerful charging sources, the Cyrix-i 400A provides a professional-grade bridge that is as reliable as it is powerful.

Unlike a simple voltage-and-timer relay, the Cyrix-i's connect/disconnect logic looks at the trend in battery voltage over time rather than a single reading, and only reverses a previous action once that trend has genuinely reversed. Four selectable switch-timing profiles let the delay before connecting or disconnecting be tuned to the installation - from an immediate response for emergency parallel-starting to a slow, filtered response that ignores brief voltage dips from cranking or a short high-amperage load.

The relay senses the voltage of both connected batteries and draws its own operating power from either side, so it will still engage even if the battery on one terminal is too low to power the Cyrix-i by itself. A push-button or remote switch input can also force the relay closed for 30 seconds to parallel the banks manually - useful for jump-starting from a house bank when the starter battery is flat. A built-in microswitch reports the relay's connected/disconnected state to an external monitor or GX device.

Features

Extreme 400A Power Handling

Engineered for high-amperage applications, this relay supports 400A continuous current and can withstand 2000A peak surges (1 second), making it safe for even the largest starter motors and high-output alternators.

Virtually Zero Voltage Drop

Unlike diode-based splitters, the Cyrix-i provides a direct relay connection. This eliminates energy waste and ensures that your battery banks receive the full charging potential from your source, critical for proper battery health.

Intelligent Microprocessor Control

Advanced switching profiles analyze voltage trends over time, preventing rapid or nuisance cycling during temporary high-current events and ensuring a smooth, stable connection.

Professional Remote Monitoring

Equipped with dedicated control connections, including a micro-switch for remote monitoring, allowing you to track the relay's status from your dashboard or control center.

Emergency Start Assist

Includes a manual override capability, allowing you to bridge your battery banks for emergency engine starting using your auxiliary power source.

Versatile Dual-Power Architecture

Internal dual power circuitry ensures the relay can close even if one battery bank is completely depleted, drawing the necessary activation energy from the healthy bank.

Specifications

Datasheets and Manuals