Victron Energy Cyrix-Li-ct Li-Ion Battery Combiner, 12/24V, 230A

Overview

The Victron Energy CYR010230412 is an intelligent Li-ion battery combiner for 12 V and 24 V battery systems, rated for 230 A continuous current and breaking capacity. It is made for installations that pair a lead acid starter battery with a LiFePO4 battery, using the VE.Bus BMS charge disconnect signal and battery voltage sensing to control when the relay connects or opens.

On a boat, this helps manage alternator or charger current between battery banks without the voltage drop normally associated with diode isolators. The unit connects when the BMS control condition is healthy and voltage reaches the required charging threshold, then disconnects when the lithium battery protection system calls for it or when battery voltage falls below the set level.

The housing is IP54 rated, measures 65 x 100 x 50 mm, and weighs about 0.27 kg, so it fits neatly into a protected DC electrical space near the battery system. Open-state current draw is less than 4 mA, which matters on vessels that may sit at the dock or on a mooring between trips.

Key features

• Works with 12 V and 24 V systems and supports 230 A continuous current and breaking capacity at either voltage.
• Parallels a lead acid starter battery and a LiFePO4 battery when the VE.Bus BMS charge disconnect output is high and voltage reaches 13.4 V on 12 V systems or 26.8 V on 24 V systems.
• Disconnects immediately when the control output becomes free floating due to cell overvoltage or cell overtemperature.
• Opens when battery voltage drops below 13.2 V on 12 V systems or 26.4 V on 24 V systems.
• Start assist function closes the relay for 30 seconds when triggered by a short negative pulse.
• Built-in transient voltage suppressor helps limit the voltage spike that can occur when the relay opens during a lithium battery protection event.
• LED status indication shows engaged, disengaged, connecting, disconnecting, and alarm states.
• IP54 protection category suits installation in a sheltered marine electrical compartment away from direct spray and washdown exposure.

Electrical and system integration

This combiner is intended for lithium installations that use a VE.Bus BMS and need controlled connection between a starter battery and a LiFePO4 battery bank. It is not a standalone lithium battery management system; it follows the control signal from the BMS and uses voltage thresholds to decide when combining is allowed.

The connect logic helps keep alternator and charger behavior practical on mixed battery systems. Since there is virtually no voltage loss through the combiner, the charging source does not need a raised output voltage just to compensate for isolator drop.

Installation and onboard use

Install the unit in a dry, accessible DC electrical area with proper cable sizing, overcurrent protection, and secure strain relief for a high-current marine battery circuit. The IP54 rating helps in a protected compartment, but the unit should not be mounted where it can be submerged, pressure washed, or exposed to constant salt spray.

This is a strong fit for cruising boats, fishing boats, and refit projects where a LiFePO4 house bank is being added while retaining a conventional starter battery. It gives the installer a controlled way to combine the banks only when the lithium battery protection logic and voltage conditions allow it.

What’s included

• Cyrix-Li-ct 12/24V-230A battery combiner
• 1 m control cable