The Victron Cyrix-Li-charge 24/48V-230A is a microprocessor-controlled battery isolator that combines a starter or auxiliary battery with a lithium house bank while charging, then disconnects once charging stops. It's built for 24V and 48V lithium battery systems and rated at 230A continuous current, making it suitable for marine, vehicle and off-grid installations where lithium battery protection matters.

Key features of this battery isolator switch

• Current rating, 230A continuous, for high-demand 24V and 48V lithium systems.
• BMS-controlled logic, microprocessor monitors battery management system signals to allow or block charging.
• Automatic operation, connects when charge voltage is detected, disconnects when charging ceases.
• Lithium-specific design, responds correctly to BMS allow-to-charge signals for LiFePO4 chemistries.
• Weight, 0.3 kg, compact enough for confined installation spaces.
• Compatibility, works with Victron BMS products that output a load or charge disconnect signal.

How it works

Unlike a standard battery combiner, the Cyrix-Li-charge is designed around a lithium BMS. When the BMS signals that charging is permitted, the relay closes and connects the charge source to the lithium bank. If the BMS issues a charge disconnect signal, perhaps due to high cell voltage or temperature, the relay opens immediately to protect the battery from overcharge.

At 230A it can handle substantial charge currents from alternators, DC-DC chargers or shore power converters in 24V and 48V systems. The microprocessor logic stops the relay chattering or cycling unnecessarily, which helps both relay and battery last longer.

Applications

• Lithium house bank charging from a starter battery or alternator on boats.
• 24V or 48V off-grid systems combining a lithium bank with a secondary charge source.
• Commercial vehicle auxiliary power systems using LiFePO4 batteries.
• Narrowboat and canal boat electrical systems after a lithium upgrade.
• Off-grid cabins and mobile installations needing BMS-controlled charge isolation.

What's in the box

• 1 x Victron Cyrix-Li-charge 24/48V-230A intelligent charge relay

Installation notes

Fit this with a qualified electrician or experienced marine/vehicle electrical engineer. It must be wired alongside a compatible lithium BMS that provides a charge disconnect output signal; without that signal the unit cannot protect the battery from overcharge. Cabling should be rated for the 230A continuous load, with appropriate fusing on both battery connections.