Victron Energy Cyrix-ct 12/24V 120A Intelligent Automatic Battery Combiner Relay CYR010120011

The Victron Energy CYR010120011 Cyrix-Li-ct 12/24-120 is a 120A intelligent battery combiner designed to parallel-connect a lead-acid starter battery and a Victron LiFePO4 battery in compatible 12V or 24V battery systems. It works with the VE.Bus BMS to control battery connection and disconnection based on battery voltage and BMS status.

The Cyrix-Li-ct provides a 120A continuous-current rating and breaking capacity at 12V or 24V. It automatically connects when appropriate charging conditions are detected and immediately disconnects when the BMS signals cell overvoltage or overtemperature, or when battery voltage falls below the specified disconnect threshold.

Key Technology

• 120A Battery Combiner
  Rated for 120A continuous current and breaking capacity in both 12V and 24V battery systems.

• 12V / 24V Automatic Operation
  Designed to operate automatically with compatible 12V or 24V electrical systems, providing intelligent battery connection and isolation.

• Lead-Acid & LiFePO4 Battery Integration
  The Cyrix-Li-ct is specifically designed to parallel-connect a lead-acid starter battery and a LiFePO4 battery under appropriate operating conditions.

• VE.Bus BMS Controlled
  Works with the Charge Disconnect output of a compatible VE.Bus BMS to help protect lithium battery cells from overvoltage and excessive temperature conditions.

• Automatic Voltage Sensing
  The Cyrix-Li-ct connects when the BMS permits charging and it detects at least 13.4V in a 12V system or 26.8V in a 24V system on one of its power terminals.

• Automatic Battery Isolation
  Immediately disengages if the BMS control output becomes free-floating due to a cell overvoltage or overtemperature condition, or when system voltage falls below its specified disconnect threshold.

• 30-Second Start Assist
  A short positive control pulse can close the relay for 30 seconds, providing a Start Assist function when required.

• Integrated Transient Voltage Suppressor
  A built-in transient voltage suppressor helps limit voltage spikes that may occur when the Cyrix suddenly disengages due to cell overvoltage or excessive temperature.

• Low Standby Consumption
  Consumes less than 4 mA when the relay is open.

• IP54 Protection
  The compact enclosure carries an IP54 protection rating for added protection against environmental exposure.

Best Uses

• Dual-Battery Systems
  Ideal for systems that need to automatically combine and isolate a lead-acid starter battery and LiFePO4 house or auxiliary battery.

• Victron LiFePO4 Battery Systems
  Designed to integrate with Victron lithium battery installations using compatible VE.Bus BMS control.

• Marine Electrical Systems
  Suitable for compatible boat and marine installations requiring intelligent separation between starter and lithium auxiliary battery banks.

• RV & Mobile Power Systems
  A compact solution for compatible recreational vehicle and mobile electrical systems using separate starter and LiFePO4 battery banks.

• Alternator Charging Applications
  The connection diagram on page 2 of the manufacturer datasheet shows the Cyrix-Li-ct installed between an alternator/starter battery circuit and a Li-ion battery system controlled by a VE.Bus BMS.

Product Specifications

Smart 120A Battery Combining for 12V & 24V Lithium Systems

The Victron Energy CYR010120011 Cyrix-Li-ct 12/24-120 combines a 120A current rating, automatic voltage sensing, VE.Bus BMS control, 30-second Start Assist, transient voltage suppression, IP54 protection, and compact 1.8 × 1.8 × 3.2-inch dimensions in a purpose-built solution for integrating lead-acid starter and LiFePO4 battery banks.

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