Victron Energy Cyrix-CT Intelligent Battery Combiner, 12/24V, 230A

Overview

The Victron Energy CYR010230010 is a Cyrix-ct 12/24V-230A intelligent battery combiner for linking battery banks during charging and separating them again when voltage drops below the charging range. It is a microprocessor-controlled relay made for 12V and 24V DC systems, with 230A continuous current capacity, a 500A cranking rating for 5 seconds, and automatic voltage detection.

On a boat, this type of combiner is commonly used between a starter battery and a service or accessory battery bank. When the starter battery reaches the connect voltage, the combiner closes so the alternator or charger can feed the other bank. When batteries are being discharged, it opens again to help keep the starting battery from being pulled down by house loads.

The Cyrix-ct avoids the voltage drop associated with diode isolators, so alternators and battery chargers do not need a higher output voltage to compensate. It also includes LED status indication, Start Assist for temporary manual parallel connection, IP54 protection, and compact 65 x 100 x 50 mm housing dimensions for installation near the battery banks or DC distribution area.

Key features

• 12V and 24V auto-ranging operation for mixed vessel electrical layouts using either system voltage.
• 230A continuous current rating supports substantial alternator, charger, and battery-bank connections when correctly wired and fused.
• 500A cranking rating for 5 seconds gives useful headroom during short starting-related load events.
• Microprocessor control monitors voltage trend, not only fixed thresholds, to reduce unwanted switching during short load changes.
• Bidirectional voltage sensing lets the combiner engage when either connected battery bank is being charged.
• Start Assist input allows a push button or switch to hold the batteries in parallel for 30 seconds during difficult starting situations.
• LED status indication helps confirm engaged, disengaged, connecting, disconnecting, and alarm conditions during setup or troubleshooting.
• IP54 protection and an operating temperature range of -40 to +60 °C suit protected marine electrical spaces away from direct bilge flooding.
• M8 connection bolts allow secure attachment of heavy DC cables for high-current battery-bank wiring.

Installation and setup

This combiner belongs in a dry, protected DC electrical area close enough to the connected battery banks to keep cable runs practical. The 65 x 100 x 50 mm housing gives enough flexibility for mounting inside a battery compartment, technical locker, or engine-room electrical panel area, as long as the location is protected from direct spray and standing water.

For a typical marine charging layout, the alternator is connected to the starter battery and the Cyrix-ct is placed between the starter bank and the accessory or house bank. Once the starter battery reaches the connect range, the combiner closes and allows the other bank to charge in parallel. When voltage falls into the disconnect range, it separates the banks again.

Electrical and system integration

The unit senses both battery sides and has a dual power supply, so it can operate from either connected battery. It will not close if one battery connection is extremely low, below 2V on a 12V battery or below 4V on a 24V battery, which helps prevent unexpected operation during installation or when a battery has been disconnected.

Start Assist can be wired to a momentary push button or switch. This is useful for boats where the starter battery may occasionally need support from the house bank, but it should still be installed as part of a properly protected DC system with suitable cable size, fusing, and battery isolation practices.

Use cases on board

This combiner is a strong match for cruising boats, fishing boats, workboats, and sailboats that run separate starting and service battery banks but charge from a shared alternator or charger. It is especially useful where the owner wants automatic charging between banks without the voltage loss of a diode isolator.

It is not a battery monitor or charge controller. Its job is to connect and separate battery banks based on voltage behavior, so it works best as part of a wider DC system that includes correct charging equipment, over-current protection, and routine battery maintenance.

What’s included

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