Victron Energy Cyrix-ct Intelligent Battery Combiner, 12/24V, 120A, IP54

Overview

The Victron Energy CYR010120011R is a Cyrix-ct 12/24V-120A intelligent battery combiner for linking battery banks automatically when charge voltage is available. It works as a microprocessor-controlled relay, connecting batteries in parallel once one battery reaches the connect voltage and disconnecting again when voltage falls below the set range.

For boats with separate starter and house batteries, this helps the alternator or battery charger share charge without the voltage drop associated with diode isolators. The unit auto-ranges for 12V or 24V systems, carries 120A continuous current, has a 180A cranking rating for 5 seconds, and uses IP54 protection for installation in sheltered onboard electrical spaces.

Key features

• Automatically connects and disconnects battery banks based on voltage, reducing manual switching during charging and discharge cycles.
• 120A continuous current rating with 180A cranking capacity for 5 seconds.
• Auto-ranging operation for 12V and 24V DC systems.
• Bidirectional voltage sensing allows the combiner to respond when either connected battery is being charged.
• Start Assist function can hold the relay engaged for 30 seconds when connected to a push button or switch.
• Very low open-state current draw of less than 4 mA helps limit standby drain.
• IP54 protection category suits dry, protected marine electrical compartments where spray and dust exposure are controlled.
• Compact 46 x 46 x 80 mm housing helps with installation near battery banks, busbars, or DC distribution equipment.

Electrical and system integration

The Cyrix-ct monitors the general voltage trend rather than reacting only to a fixed instant threshold. This helps prevent unwanted relay switching when a short, high-current load pulls voltage down or when a large discharged battery bank is first connected.

Connect voltage ranges are 13.0V to 13.8V on 12V systems and 26.0V to 27.6V on 24V systems. Disconnect voltage ranges are 11.0V to 12.8V on 12V systems and 22.0V to 25.7V on 24V systems, with delay timing that changes according to the voltage level.

Installation and setup

In a typical marine installation, the alternator charges the starter battery first, and the Cyrix-ct closes once the starter battery has reached the connect voltage. The house battery, bow thruster battery, or another onboard battery bank can then receive charge through the combiner without requiring alternator output compensation for diode voltage loss.

The 120A model uses M6 connection posts with long bolts that allow more than one power cable connection where the installation permits it. The control cable is not included with this 120A version, so any Start Assist wiring should be planned as part of the installation.

Fit and onboard use

This combiner is a good match for small to mid-size boats that use separate starter and domestic battery banks and need automatic charging control from an alternator, shore-power charger, or other DC charging source. It is especially useful where simple battery separation is wanted without adding the voltage loss of a diode isolator.

The operating temperature range is -40°C to +60°C, which gives it a wide working range for protected lockers, engine-area electrical panels, and DC distribution spaces. Mount it where the terminals are protected from accidental contact and where the IP54 housing is not exposed to direct washdowns or standing water.