Victron Cyrix-i Intelligent Battery Combiner 12/24V-400A
Victron Cyrix-i Intelligent Battery Combiner 12/24V-400A
400A Continuous | Trend-Based Switching | Zero Voltage Drop

DESCRIPTION
Victron Cyrix-i 12/24V-400A: Intelligent Battery Combiner for Dual-Battery Systems
Advanced Voltage Sensing and Smart Switching for Reliable Parallel Charging
The Victron Cyrix-i 12/24V-400A is a microprocessor-controlled intelligent battery combiner designed to manage dual-battery systems in vehicles, boats, and off-grid installations. Unlike conventional voltage-sensitive relays (VSRs) that rely on simple voltage thresholds and fixed timers, the Cyrix-i analyses voltage trends to prevent nuisance switching caused by momentary loads or deeply discharged batteries. This ensures your auxiliary battery charges reliably without unnecessary cycling, extending the lifespan of your entire system.
With a continuous current rating of 400 A and a peak capacity of 2000 A, this combiner handles high-demand applications such as winching, bow thrusters, or large inverter loads. The auto-ranging input (8-36 VDC) automatically detects 12V or 24V systems, simplifying installation and reducing inventory complexity for installers.
Why Trend-Based Switching Matters
Standard battery combiners often disconnect under short, high-current loads or fail to engage a depleted battery bank because the voltage collapses below the disconnect threshold. The Cyrix-i overcomes these limitations by evaluating the voltage trend over time. It only reverses a connection if the trend direction changes for a sustained period, preventing false triggers and ensuring stable parallel operation. Four selectable timing profiles allow customisation for different battery chemistries and usage patterns.
Zero Voltage Drop for Maximum Efficiency
Diode-based isolators introduce a forward voltage drop (typically 0.6-0.7 V), requiring higher alternator or charger output voltages and wasting energy as heat. The Cyrix-i uses high-current relay contacts, resulting in virtually no voltage loss. This means your batteries receive the full charging voltage, improving charge efficiency and reducing strain on your alternator or charger.
Bidirectional Sensing and Dual Power Supply
The Cyrix-i monitors voltage on both connected batteries and can be powered from either side. If one battery is too low to operate the relay, the other battery provides the necessary power. This ensures the combiner engages even when the starter battery is deeply discharged, as long as the auxiliary battery has sufficient voltage. For safety, the unit will not close if either terminal voltage is below 2 V (12V), 4 V (24V), or 8 V (48V), preventing unexpected operation during installation or maintenance.
Emergency Parallel Start Feature
A built-in push-button or remote switch input allows manual parallel connection for 30 seconds, providing an emergency start assist if the starter battery is flat. This feature is invaluable for marine, RV, and off-road applications where a failed start could leave you stranded.
Key Features
- 400 A continuous / 2000 A peak current rating for high-demand loads
- Intelligent trend-based switching prevents nuisance disconnects and ensures reliable charging
- Auto-ranging 12/24V detection simplifies installation and reduces setup errors
- Virtually zero voltage drop compared to diode isolators, maximising charge efficiency
- Bidirectional voltage sensing and dual power supply for robust operation
- Emergency start assist via push-button or remote switch for peace of mind
- Microswitch output for remote status monitoring
- Compact, vibration-resistant design with durable metal mounting bracket
Built for Demanding Environments
Encased in a rugged housing with high-current copper terminals, the Cyrix-i is engineered for the harsh conditions of engine rooms, vehicle chassis, and marine installations. The bicolour LED provides at-a-glance status indication, while the microswitch terminals enable integration with remote monitoring systems. Weighing just 0.9 kg, it adds minimal weight while delivering industrial-grade reliability.
Applications
Ideal for dual-battery systems in 4WDs, caravans, motorhomes, boats, and commercial vehicles. Use it to combine a starter battery with an auxiliary deep-cycle battery, or to link multiple battery banks for charging from a single alternator or charger. The Cyrix-i is also suitable for 24V systems in trucks, buses, and heavy equipment.
Upgrade Your Battery Management Today
Replace unreliable diode isolators or basic VSRs with the Victron Cyrix-i Intelligent Battery Combiner and experience smarter, more efficient parallel charging. Order now to ensure your dual-battery system delivers dependable power when you need it most.
SKU: Vic-CYR010400000
SPECIFICATIONS
Specifications
| Model | Cyrix-i 12/24-400 |
|---|---|
| Continuous Current | 400 A |
| Peak Current | 2000 A During 1 Second |
| Input Voltage | 8-36 VDC |
| Switch Timing Profiles | 4 Selectable Profiles |
| Over Voltage Disconnect | 16 V / 32 V / 64 V |
| Current Consumption When Open | 4 mA |
| Emergency Start | Yes, 30 s |
| Micro Switch For Remote Monitoring | Yes |
| Status Indication | Bicolour LED |
| Weight | 0.9 kg (2.0 lbs) |
| Dimensions (H X W X D) | 78 x 102 x 110 mm (3.1 x 4.0 x 4.4 in) |
| SKU: | Vic-CYR010400000 |
| Barcode: | 8719076022251 |
| Model #: | CYR010400000 |
| MPN: | CYR010400000 |
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














































