Victron Cyrix-Li-Charge 230A: Intelligent Charge Relay for LiFePO4 Battery Systems

Precision Charge Control for Lithium Battery Protection

The Victron Cyrix-Li-Charge 12/24V-230A is a microprocessor-controlled intelligent charge relay designed to integrate seamlessly with Victron VE.Bus BMS and LiFePO4 batteries. It acts as a critical second line of defence, automatically connecting or disconnecting a battery charger based on signals from the BMS to prevent cell overvoltage and over temperature conditions. This ensures your lithium battery bank remains within safe operating limits, extending service life and maintaining system reliability in demanding mobile, marine, and off-grid applications.

Unlike generic voltage sensing relays, the Cyrix-Li-Charge responds directly to the VE.Bus BMS Charge Disconnect output, providing a coordinated protection strategy that generic relays cannot offer. This reduces the risk of cell damage from overcharging, a common failure point in lithium systems without proper BMS integration.

How It Works

The Cyrix-Li-Charge engages the charger connection with a 3-second delay when the BMS Charge Disconnect signal is high and it detects sufficient voltage on both the charger and battery terminals. It disengages immediately if the BMS signals a fault, such as cell overvoltage or over temperature, isolating the charger to prevent further stress on the cells. After a brief recovery, it attempts to reconnect automatically, with progressively longer delays if faults persist, preventing rapid cycling that could damage components.

Key Features

• 230 A continuous rating at 12 V or 24 V for high-current charging systems
• Direct VE.Bus BMS control for coordinated lithium battery protection
• Immediate disengagement on cell overvoltage or over temperature signals
• Automatic reconnection with intelligent delay logic to avoid nuisance cycling
• Built-in transient voltage suppression protects against voltage spikes during disconnection
• LED status indicator for at-a-glance operational and fault monitoring
• Low current consumption (<4 mA when open) minimises parasitic drain
• IP54 rated enclosure resists dust and water splashes for harsh environments
• 3/8"-16 (Approx. M10) stud terminals suit heavy-duty lugs for secure, low-resistance connections

Designed for Demanding Environments

With an IP54 protection rating and robust construction, the Cyrix-Li-Charge is built to withstand the vibration, temperature swings, and moisture common in vehicle and marine installations. The compact footprint (65 x 100 x 50 mm) and integrated mounting flanges allow flexible installation in tight spaces, while the included 1-metre control cable simplifies connection to the VE.Bus BMS.

Applications

This charge relay is ideal for systems where a VE.Bus BMS manages Victron LiFePO4 batteries but the charger cannot be directly controlled by the BMS. Typical uses include:

• Marine and RV lithium battery systems with high-output alternators or shore chargers
• Off-grid solar installations requiring reliable charge disconnect for battery longevity
• Commercial vehicle and emergency service setups where battery safety is critical

Why Choose the Cyrix-Li-Charge?

Generic charge relays lack the intelligence to interpret BMS fault signals, leaving lithium batteries vulnerable to overcharge damage. The Cyrix-Li-Charge bridges this gap, delivering precise, automated protection that reduces the risk of thermal runaway and premature capacity loss. Its 230 A continuous rating supports large battery banks, while the low standby draw preserves battery state of charge during storage.

For installers and system integrators, the Cyrix-Li-Charge simplifies wiring and enhances safety by centralising charge control through the proven Victron ecosystem. It eliminates the need for complex workarounds or additional contactors, saving time and reducing potential failure points.

Take Control of Your Lithium Charging

Equip your Victron LiFePO4 system with the Cyrix-Li-Charge 230A to ensure every charge cycle is safe, controlled, and optimised for battery health. Add to your system today and experience the confidence of fully integrated lithium protection.