SKU: 33978921667

Victron Cyrix-i Intelligent Battery Combiner 12/24V-400A

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Description

Victron Cyrix-i Intelligent Battery Combiner 12/24V-400AVictron 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

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.

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 33978921667

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Verified Purchase
Jack & Ann Kenny
Birmingham, US
★★★★★ 5
Nice Product and Customer Service
I ordered this BlastIR Wireless Pro IR Repeater from Sewell to replace a wired version of an IR repeater from another company. We have moved our TV on to a wall location and are in the process of hiding all the wiring out of sight behind walls and/or in a cabinet. We still have some wires to go, but this product has enabled us to eliminate the IR wiring all together. It's a real improvement in both looks and performance over the cheaper, wired version we originally tried. The BlasterIR's Receiver is the component that faces the room and receives the IR signal from our remote controls. It's small enough to fit in the space between our sound bar and the bottom of the TV. It's range is great for our room size (about 22' long and 18' wide) and picks up the remotes signal from a side angle that's almost parallel to the TV itself. The receiver is powered through one of the USB ports integrated into the TV (although the device itself supports either a USB or regular plug-in option). I haven't used them yet but Sewell appears to have provided a few options to help with affixing the IR devices in their final positions including some adhesive pads and a magnetic pad option as well. I'm still playing around with the permanent placement of the IR Blaster Emitter. It sits inside a closed cabinet and faces the concealed cable box receiver, router and DVR components. It retransmits the various IR signals it receives from the IR receiver by blasting that signal to anything it faces. I just placed it in the cabinet about 5" away from the devices I wanted to control, plugged it in and it worked with no other set up. So far the BlastIR is working seamlessly and with much better function response time than the cheaper IR version we'd tried at first. The lag time between when a button is pressed on the remote control and the action taking place on the device I'm communicating with is minimal. The emitter itself is plugged into an outlet on a surge protector powering the other in-cabinet devices, although it too could be powered via the provided USB connection if desired. As a note, we did experience a shipping issue during our ordering process. The order it self was processed quickly and shipped in a timely manner. However, there was an issue with our actual receipt of the product and the USPS who reported it delivered to our mailbox when in fact it had not been. Regardless, we reached out to Sewell directly and they quickly resolved the issue for us with no problems and in a timely manner. I would recommend both this IR Blaster Pro product as well as Sewell as a trusted company itself.
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Reviewed in the United States on February 8, 2021
S
Verified Purchase
Scott C
Pawtucket, US
★★★★★ 3
Does NOT Transmit Through Walls
Quick and easy setup! Works great within the room. However, will not work effectively between walls (i.e. - AV closet to living room).
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Reviewed in the United States on February 8, 2026
H
Verified Purchase
HSNYC
Belleville, US
★★★★★ 5
Works perfectly - great product
My MBR TV set-up incorporates a cable box set up in a closet about 50 feet from the TV (hung over a fireplace). When it was set up the A/V used a wired infra-red set up that was wired thru the walls, under the floor, into the closet. Unfortunately some mice nibbled on the wiring and it does not work. I have tried everything including the Next Generation extender (over the years bought 6 of them for different TV's) and most recently the Startech. The Next Generation have not been updated in years and over time completely lose their ability to operate. No customer service at all; emails go into a black hole. I had high hopes for the Startech. Easy to set up and worked out of the box. The problem is the lag time. I could live with it when watching live TV, but it was totally impossible when it came to playing back programs from the DVR (which is cloud based). I was losing hope until I tried the Sewell Blaster. Took me less then 5 minutes to set up and it worked instantly. Little or no lag to speak of and I couldn't be happier. NB. Speaking of Sewell, the absolutely BEST way to control your HDMI based TV is the Sewell Direct SW-30062 Dual Band InjectIR sold by Amazon for $55. This is truly plug 'n play and operates with absolutely no lag. Bought 2 of these to operate TV's in my apartment where I had to hide boxes in closets. Well made, great instructions (coordinated with the devices) and I just love this product. I bought mine direct from Sewell ) same price) because I couldn't find them on Amazon when I needed them, but they have a great return policy and I'm told great C/S. If you can't use these then go for the Blaster.
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Reviewed in the United States on November 30, 2018
A
Verified Purchase
Amazon Customer
Cuba, US
★★★★★ 5
Excelente
Excelente
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Reviewed in the United States on March 12, 2026
S
Verified Purchase
S. McCarty
Pawtucket, US
★★★★★ 5
Excellent fit and value - recommended buy
Size: 3+12+12+2+1 pack
I rarely write reviews, but I'm so impressed by the fit and quality of this set that I made an exception. I'd been running my eufy 11S without brushes, and have been cleaning and reusing the filters for a while now and finally decided to buy replacements. The kit came packed well with everything in order and no damage. I replaced all of the worn parts and installed the brushes and did a test run - everything worked great. I expected some fitment issues because I've seen that with other kits, but I had no issues. The fact that you get multiples of almost everything is icing on the cake. Oh, and I wasn't paid or given anything in exchange for this review, as much as that's worth now, haha. I can recommend getting this kit for your robot vacuum, if it's the right set for your model.
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Reviewed in the United States on February 6, 2025

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