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Victron Cyrix-ct Intelligent Battery Combiner Kit 12/24V-120A VSR
Victron Cyrix-ct Intelligent Battery Combiner Kit 12/24V-120A VSR
120A Bidirectional VSR Kit with 6m Cable, Start Assist, 12/24V Auto-Ranging
Highlights:Cyrix Relay: Intelligent voltage sensing relay for automatic battery paralleling,Battery Cables: Includes 6m red and 0.5m black high-current battery cables,Cable Ties: Set of black nylon cable ties for secure wire routing,Terminal Lugs: Heavy-duty copper lugs for reliable electrical terminations,Heat Shrink: Red adhesive-lined heat shrink for terminal insulation.
Technical wiring schematic illustrating the parallel installation of domestic and starter batteries via the Cyrix combiner relay, including fuse locations and optional start assist switch circuit.
Key features: 120A continuous current rating, 12V and 24V auto-ranging system voltage detection, IP54 protection category for dust and splash resistance, 150A maximum alternator rating compatibility, Integrated emergency start assist function for 30 second intervals. 
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DESCRIPTION
Victron Cyrix-ct 120A Intelligent Battery Combiner Kit: Reliable Dual-Battery Management for 12V and 24V Systems
Advanced Voltage-Sensitive Relay for Automatic Battery Isolation and Parallel Charging
The Victron Cyrix-ct 120A is a microprocessor-controlled bidirectional voltage sensitive relay (VSR) designed to intelligently manage multiple battery banks in vehicles, boats, and off-grid installations. This kit includes the relay, heavy-duty cables, and terminals, providing a complete solution for adding a second or third battery without modifying factory wiring. The Cyrix-ct automatically parallels the starter and auxiliary batteries when a charging source is present and isolates them when charging stops, ensuring the starting battery is always protected from deep discharge.
Unlike basic voltage-sensing relays, the Cyrix-ct employs intelligent battery monitoring to prevent rapid cycling. Its software analyses voltage trends over time, not just instantaneous thresholds, so it only switches when a genuine change in charge state is detected. This eliminates unnecessary relay chatter and extends the life of both the relay and connected batteries. The unit is auto-ranging for 12V and 24V DC systems, making it versatile for cars, trucks, motorhomes, marine vessels, and solar setups.
Key Features of the Cyrix-ct 120A Combiner
- 120 A continuous current rating with 180 A cranking assist for 5 seconds, suitable for alternators up to 150 A
- Bidirectional operation – engages when either battery bank receives charge, from an alternator, shore charger, or solar controller
- Trend-based switching logic prevents false triggering and relay cycling, improving reliability in fluctuating voltage conditions
- Emergency start assist – a momentary switch can be wired to the dedicated terminal to parallel batteries for 30 seconds, aiding engine cranking if the starter battery is low
- Low power consumption – draws less than 4 mA when open, minimising drain on the batteries when the engine is off
- IP54 protection – resistant to dust and water splashes, suitable for engine bays and exposed marine environments
- Compact design – 46 x 46 x 80 mm footprint allows installation in tight spaces
Complete Installation Kit with Premium Cables
This kit includes everything needed for a professional installation. The supplied cables are sized for the 120 A rating, with a 6-metre red 10 mm² power cable for the main run and a 0.5-metre black 10 mm² ground cable. A pre-assembled control cable with an M8 lug and 6.3 mm fast-on terminal simplifies the start assist wiring. Copper lugs with insulation sleeves (two M8 and four M6) and cable ties are provided to ensure secure, tidy connections. No cutting into factory wiring is required, preserving vehicle warranties and reducing installation time.
Why Choose the Victron Cyrix-ct Over Standard Relays?
Conventional VSRs often rely on simple voltage thresholds with fixed time delays, which can lead to nuisance switching when loads cause temporary voltage dips. The Cyrix-ct’s intelligent algorithm evaluates the voltage trend over a period, reversing a connection only if the trend has genuinely reversed. This is particularly beneficial in systems with variable loads, such as fridges or inverters, where voltage can fluctuate without indicating a change in charge state. The result is stable, predictable battery management that reduces wear on contacts and prevents unintended discharge of the starter battery.
Additionally, the bidirectional design means the relay will close not only when the engine is running but also when a mains charger or solar regulator is connected to the auxiliary bank. This allows all batteries to benefit from any charging source, maximising energy utilisation and simplifying system design.
Applications
- 4WD and camping vehicles – keep the cranking battery isolated while running accessories from a deep-cycle auxiliary battery
- Marine installations – automatically combine battery banks during shore power charging or alternator operation, with emergency parallel for engine starting
- Caravans and motorhomes – charge house batteries from the vehicle alternator while driving, and from solar when parked
- Commercial vehicles – manage multiple battery banks in trucks, buses, and emergency vehicles with high alternator outputs
- Off-grid solar systems – use as a battery combiner to share charge between banks without complex wiring
Installation Considerations
The Cyrix-ct requires a common negative reference between all batteries, which is standard in most 12V and 24V vehicle and marine systems. The relay should be mounted close to the batteries, with the included cables cut to length as needed. Fusing is recommended on all positive connections (not included) to protect against short circuits. The start assist terminal can be connected to a momentary push-button switch on the dashboard for convenient emergency starting.
With its robust construction, intelligent control, and comprehensive kit contents, the Victron Cyrix-ct 120A provides a reliable and long-lasting solution for dual-battery management. Whether you are building a touring setup, upgrading a marine electrical system, or adding redundancy to an off-grid power installation, this combiner delivers consistent performance and peace of mind.
Equip your vehicle or vessel with the Victron Cyrix-ct 120A Intelligent Battery Combiner Kit today and ensure your batteries are always charged and ready, without the risk of a flat starter battery.
SKU: Vic-CYR010120110R
SPECIFICATIONS
Specifications
| Model | Cyrix-ct 12/24-120 |
|---|---|
| Part Number | CYR010120110R |
| Relay Type | Bidirectional voltage sensitive relay |
| Continuous Current | 120 A |
| Cranking Rating (5 Seconds) | 180 A |
| Maximum Alternator Rating | 150 A |
| Auto Ranging | 12/24 V |
| Connect Voltage (Delay Appr. 10 Minutes) | 13 V / 26 V |
| Connect Voltage (Delay Appr. 4 Seconds) | 13.8 V / 27.6 V |
| Disconnect Voltage (Delay Appr. 10 Minutes) | 12.8 V / 25.6 V |
| Disconnect Voltage (Delay Appr. 4 Seconds) | 11.8 V / 23.6 V |
| Over Voltage Disconnect | 16 V / 32 V |
| Current Consumption When Open | <4 mA |
| Current Consumption When Closed | 12 V: 220 mA; 24 V: 120 mA |
| Operating Temperature Range | -40 to +60 °C |
| LED Status Indication | No |
| Start Assist | Yes, 30 sec |
| Protection Category | IP54 |
| Weight | 0.11 kg (0.24 lbs) |
| Dimensions (H x W x D) | 46 x 46 x 80 mm (1.8 x 1.8 x 3.2 in) |
| Power Studs | M6 |
| Installation Requirement | 12 V or 24 V installations with a negative common |
| Included Red Cable | 6 m red 10 mm² cable |
| Included Black Cable | 0.5 m black 10 mm² cable |
| Included Control Cable Assembly | 0.2 m black 1.5 mm² cable assembly with M8 lug and 6.3 mm fast on terminal |
| Included M8 Cable Lugs | 2 pcs M8 cable lug with insulation sleeve |
| Included M6 Cable Lugs | 4 pcs M6 cable lug with insulation sleeve |
| Included Cable Ties | 4 pcs cable tie 150 mm |
| SKU: | Vic-CYR010120110R |
| Barcode: | 8719076022169 |
| Model #: | CYR010120110R |
| MPN: | CYR010120110R |
WARRANTY
Victron Energy Limited Warranty Policy
Direct Customers
Victron Energy provides the following warranty to any direct customer (OEM, distributor or dealer) in relation to any products that Victron Energy has directly sold to the direct customer. This warranty is not an end-user warranty between Victron Energy and an end-user, and end-users shall not have any rights or remedies under this limited warranty towards Victron Energy directly. The direct customer shall, in turn, ensure that the end-user is provided with a warranty identical to this warranty, subject to applicable local mandatory law.
End-Users
Victron Energy may also provide a warranty directly to end-users, in which case the below warranty conditions equally apply to such warranty. In that case, end-users shall claim their warranty at their place of purchase or through the original direct customer of Victron, which can be found through the support section on Victron’s website https://www.victronenergy.com/support. Hence, the direct customer shall on behalf of Victron Energy deal with any warranty claims made under any warranty that Victron Energy may provide directly to end-users. This support section on Victron’s website https://www.victronenergy.com/support will provide further guidance on the procedure for end-users to make a claim under this limited warranty.
If the end-user is a consumer – a natural person who is acting for purposes which are outside that person's trade, business, craft or profession – the following applies. The rights and remedies granted to the consumer under this limited warranty are without prejudice to the consumer’s statutory rights. Furthermore, the consumer is entitled by law to remedies from the seller free of charge in the event of a lack of conformity of the goods (such as repair, replacement, price reduction or rescission), which remedies are not affected by this limited warranty.
Warranty
Victron Energy warrants its products to be free from defects in workmanship and materials for a period of 5 years from the date of purchase by the original end-user, with a maximum of 66 months from the Victron Energy invoice date. Exceptions on this are: lead-acid batteries: 2 years from date of purchase by the original end-user, with a maximum of 30 months from the Victron Energy invoice date, Lithium batteries: 3 years from date of purchase by the original end-user, with a maximum of 42 months from the Victron Energy invoice date. In addition to this, proof of correct battery usage is required when making a battery warranty claim.
For a 10% surcharge on the current net price for products that came with a 5-year warranty, an additional 5 years of warranty can be purchased by Victron’s direct customers, bringing the total warranty to 10 years. Warranty extensions need to be applied for ultimately one year before the expiration of the original term. Victron may ask proof that the product was still functional at the time of purchase of the extended warranty.
During the warranty period, Victron Energy will, at its discretion, repair, replace or (partly) credit the defective product free of charge. The warranty does not include performing or reimbursing de‐installation, transportation, and re‐installation.
This warranty will be considered void if the unit has suffered any physical damage or alteration, either internally or externally, and does not cover damages arising from improper use like:
- Reversed battery polarity.
- Inadequate connection.
- Mechanical shock or deformation.
- Contact with liquid or oxidation by condensation.
- Use in an inappropriate environment (dust, corrosive vapour, humidity, high temperature, biological infestation, etc.).
- Breakage or damage due to lightning.
- Connection terminals and screws destroyed or other damages, like overheating, due to insufficient tightening.
- For any electronic breakage except due to lightning (reverse polarity, over‐voltage due to external cause), the state of the internal control diode and/or the input/output X and Y capacitors determine the warranty.
This warranty will not apply where the product has been misused, neglected, improperly installed, or repaired by anyone other than Victron Energy or one of its authorized Repair Centres. In order to qualify for the warranty, the product must not be disassembled or modified.
This warranty and our warranty obligations thereunder (repair, replacement or credit) are the direct customer’s and, if applicable, the end-user’s sole rights and remedies and our sole obligations with respect to any defective and/or non-conforming product or breach of warranty and is subject to and without prejudice to the limitations of liability in this warranty.
Victron Energy shall not be liable for damages, whether direct, incidental, special, or consequential, even caused by negligence or fault.
As a product requires service, it must be brought back to the place of purchase. In case no contact can be made with the merchant, or if he is either unable or not allowed to provide service, direct contact should be made with Victron Energy through the support section on Victron’s website.
In case Victron Energy replaces a product, it will own the replaced product. Victron Energy owns all parts removed from repaired products. Victron Energy uses new or reconditioned parts made by various manufacturers when performing warranty repairs or building replacement products.
If Victron Energy repairs or replaces a part of a product, its warranty term is not extended: the warranty will apply for the remaining term of the original warranty term. For example, if Victron Energy replaces a product with a 5-year warranty after 3 years, the warranty of this product will apply for another 2 years, with a minimum of 6 months.
All remedies and the measure for damages are limited to the above. Victron Energy shall in no event be liable for consequential, incidental, contingent or special damages, even if having been advised of the probability of such damages.
The foregoing limited warranty provided by Victron Energy is in lieu of any other warranties, express or implied arising by law, course of dealing, course of performance, usage of trade or otherwise, of any kind whatsoever including, without limitation, warranties of merchantability or fitness for a particular purpose, with respect to any product. The above is without prejudice to the arrangement for consumers detailed above.
Life Support Policy
As a general policy, Victron Energy does not recommend the use of any of its products in life support applications where failure or malfunction of Victron Energy's product can be reasonably expected to cause the failure of the life support device or to significantly affect its safety or effectiveness. Victron Energy does not recommend the use of any of its products in direct patient care. Victron Energy will not knowingly sell its products for use in such applications unless it receives in writing assurances satisfactory to Victron Energy that the risks of injury or damage have been minimized, the customer assumes all such risks, and the liability of Victron Energy is adequately protected under the circumstances.
Warranty on repairs for products outside their warranty period
The warranty period on products that are outside their warranty period and have been repaired by Victron Energy or one of the Victron Energy Repair centres is six (6) months from delivery. The same applies to spare parts and circuit boards that have been supplied or repaired by Victron Energy.
Transport
It is the responsibility of the sender to sufficiently package these products. The transport must be organized in a way to avoid any damage, especially when a single unit or heavy unit is sent.
Severability
If a part of the terms and conditions of this warranty is held invalid, void or unenforceable due to any particular national or international legislation, it shall not affect other parts of the terms and conditions of this warranty.
Applicable law
This warranty is exclusively governed by the laws of the Netherlands, to the exclusion of the UN Convention on Contracts for the International Sale of Goods.
Contact details
Victron Energy B.V. | De Paal 35, 1351 JG Almere, The Netherlands | https://www.victronenergy.com/support
