Victron Energy Cyrix-i 400 Intelligent Battery Combiner

Product Overview

The Victron Energy Cyrix-i 400 is a microprocessor-controlled, heavy-duty contactor designed to automatically connect batteries in parallel when one battery reaches a pre-set charging voltage and disconnect them when the voltage drops below a float level. It serves as an excellent replacement for diode isolators, offering virtually no voltage loss, which means the output voltage of alternators or battery chargers does not need to be increased.

Starter Battery Priority: In a typical setup, the alternator is connected directly to the starter battery. Accessory batteries, such as those for bow thrusters or other loads, are connected to the starter battery via Cyrix battery combiners. The Cyrix engages when it senses the starter battery has reached its connect voltage, allowing parallel charging of other batteries. This prioritizes the starter battery, ensuring it remains charged.

Bidirectional Voltage Sensing: The Cyrix monitors the voltage of both connected batteries. It will engage if either battery is being charged, for instance, if an accessory battery is being charged by a separate battery charger.

Intelligent Battery Monitoring: Four different connect/disconnect profiles can be selected to suit specific system requirements, preventing rapid cycling.

Auto-Ranging: The Cyrix-i 12/24 automatically adjusts to a 12V or 24V system, and the Cyrix-i 24/48 adjusts to a 24V or 48V system.

Status Indication: A bicolour LED indicator shows the status: Red for contactor open, Red/Green for timer active, and Green for contactor closed.

Remote Monitoring: A micro switch is available for remote status monitoring.

Installation Guide

The Cyrix-i is suitable for installations with a negative common system.

1. Disconnect the negative terminals of both batteries.
2. Place the Cyrix unit as close as possible to the smallest battery (typically the starter battery).
3. Connect the positive terminals of both batteries to the brass bolts on the Cyrix (labeled 'Battery 1' and 'Battery 2'). Install a fuse (maximum 400A) in series with these connections, sized appropriately for the wire gauge.
4. Connect the common battery negative terminal to the Cyrix's 'battery -' terminal.
5. Reconnect the negative terminals of both batteries.
6. An optional emergency start push button can be wired to the 'start assist' connection. Engaging this will cause the relay to close for 30 seconds. Alternatively, a parallel connect switch can be used to keep the relay engaged as long as the switch is closed.
7. An auxiliary micro switch can be connected for remote monitoring of the unit's status.

Technical Specifications

Diagrams and Controls

Wiring Diagram: The diagram illustrates the typical installation of the Cyrix-i battery combiner. An alternator is shown connected to a starter motor and a starter battery. The Cyrix-i unit is positioned between the starter battery (labeled 'Battery 1') and a domestic battery bank (labeled 'Battery 2'). Power from the alternator and a battery charger are shown connecting to the starter battery. The 'Start Assist' terminal on the Cyrix-i is depicted with a connection to the positive terminal of the starter battery, enabling manual override for starting. The diagram emphasizes the parallel connection of batteries facilitated by the Cyrix-i.

Profile Select Switch: A diagram shows a small switch, accessible after removing a cover, labeled 'Profile Select Switch'. This switch is used to select one of the four operating profiles for the Cyrix-i unit.

Connect/Disconnect Profiles

The Cyrix-i offers four selectable profiles to manage battery connections based on voltage thresholds. Note: For 24V systems, multiply the voltage values by 2. For 48V systems, multiply by 4.

Profile 0 (Default)

Profile 1

Profile 2

Profile 3

Notes on Profiles:

• After connecting 3 times, the minimum time to reconnect is 1 minute to prevent 'rattling'.
• The Cyrix will not connect if the voltage on one of the battery connections is less than 2V* (to prevent unexpected switching during installation).
• The Cyrix will always connect if the 'start assist' is activated, as long as the voltage on one of the battery connections is sufficient to operate the Cyrix (approximately 10V*).