Voltage sensitive relay kit – includes Victron Cyrix-ct 120A & all required components

Cyrix-ct 120A Battery Combiner – Voltage Sensitive Relay kit

This voltage sensitive relay kit includes everything you’ll need to wire in the Victron Cyrix-ct 120A as part of your campervan electrical system. It includes:

• Victron Cyrix-ct 120A battery combiner
• 1x 125A MEGA fuse
• 1x MEGA fuse holder
• Red & black cable (available in 3m, 6m and 9m lengths – 35mm2 included for 3m lengths, 50mm2 included for 6m & 9m lengths, and 1.5mm2 included for the control cables)
• Cable lugs to connect to the starter battery & positive busbar

Please note that no crimp connectors are included, as we have presumed you will already have an assorted pack of crimp connectors from wiring in the rest of your electrical system.

Cyrix-ct 120A battery combiner

The Cyrix-ct 120A battery combiner is a voltage sensitive relay which combines your leisure battery and starter battery when a pre-set voltage is reached (indicating that the battery is being charged), and disconnects when the voltage decreases below float level (indicating that one or more batteries are being discharged). This 120A model can charge a leisure battery at a rate of up to 120A/hr. For more information, read our article, What is a split charge relay?

PLEASE NOTE: The Cyrix-ct battery combiner is a voltage sensitive relay that cannot be used with vehicles that have Euro 5 or Euro 6 engines, as they use a smart alternator. Most vehicles registered after September 2013 will be Euro 5 or Euro 6, and you can also check this on your V5C. If you have such a vehicle, you should instead use a battery to battery charger.

Use cases

It is only possible to use a voltage sensitive relay (VSR) in a vehicle that doesn’t have a Euro 5 or Euro 6 engine. Further to this, you can only use a VSR if you have lead acid (i.e. not lithium) leisure batteries.

Intelligent battery monitoring

Some voltage sensitive relays will disconnect a battery in case of a short but high amperage load. A battery combiner also may fail to connect a large but discharged battery bank because the DC voltage immediately drops below the disengage value once the batteries are connected. The software of the Cyrix-ct 120A does more than simply connect and disconnect based on battery voltage and with a fixed time delay. The Cyrix-ct 120A looks at the general trend (voltage increasing or decreasing) and reverses a previous

action only if the trend has reversed during a certain period of time. The time delay depends on the voltage deviation from the trend.

Protection against overheating

The Cyrix will disengage in case of excessive contact temperature, and reengage again after it has cooled down.

Looking for a battery to battery charger instead?

View the full range of Victron Orion B2B chargers

Products that give back

We are members of 1% for the Planet. This means that for every product purchased from Climbingvan, 1% of the total cost will be given to The Honnold Foundation, to provide solar power to underprivileged communities. If you want your electrical system to have more of a positive impact, purchasing your components from us at Climbingvan will mean you can give back as well as powering your off-grid system.

Product SKU: CYR010120011-1