Description
xVictron Cyrix-Li-charge 12/24V-120A Intelligent Charge Relay | CYR010120430
The Cyrix-Li-charge 12/24V-120A is a microprocessor-controlled charge relay designed to combine a lithium (LiFePO4) service battery with a starter battery in 12V or 24V systems. It allows the alternator or charger to charge both battery banks simultaneously, while protecting the lithium battery from unsafe charging conditions. Suitable for marine, vehicle and off-grid installations where a lithium service bank is paired with a conventional lead-acid starter battery.
Key Features
- Rated at 120A continuous current, suitable for high-demand dual-battery systems on 12V or 24V platforms.
- Microprocessor-controlled operation: the relay connects and disconnects based on voltage thresholds, with no manual intervention required during normal use.
- Designed specifically for lithium battery systems: the relay opens immediately if the Battery Management System (BMS) sends a charge disconnect signal, preventing overcharge of the lithium bank.
- Connects when the starter battery reaches approximately 13.2V (12V system) or 26.4V (24V system), ensuring the alternator is not loaded before the engine is running.
- Disconnects when voltage drops below threshold, preventing the lithium bank from discharging into the starter battery.
- Compatible with Victron BMS charge disconnect output, allowing the BMS to take direct control of the relay.
- Compact and lightweight at 0.12 kg, with a straightforward wiring configuration for professional installation.
Product Overview
The Cyrix-Li-charge operates differently from a standard battery combiner. In a conventional combiner, the relay closes whenever either battery reaches a set voltage. The Cyrix-Li-charge is configured so that the lithium service battery side is passive: the relay only closes when the starter battery voltage rises, indicating that charging is actively taking place. This prevents the lithium bank from back-feeding into the starter battery when the engine is off.
The critical feature for lithium installations is the BMS integration. Victron lithium batteries with a BMS can output a charge disconnect signal when the battery is full or when a cell imbalance is detected. The Cyrix-Li-charge responds to this signal by opening the relay immediately, isolating the lithium bank from the charging source. This makes it a necessary component in any dual-battery system where a Victron lithium battery is used alongside a lead-acid starter battery charged by an alternator.
The unit handles 12V and 24V systems without any configuration change, making it a practical stock item for installers working across different vehicle and vessel platforms. At 120A, it covers the majority of alternator outputs found in commercial vehicles, motorhomes, and narrowboats.
Technical Specifications
| Parameter | Value |
| SKU | CYR010120430 |
| Voltage Compatibility | 12V / 24V (auto-detect) |
| Continuous Current Rating | 120A |
| Connect Voltage (12V system) | ~13.2V |
| Connect Voltage (24V system) | ~26.4V |
| BMS Integration | Compatible with Victron BMS charge disconnect output |
| Battery Chemistry | Lithium (LiFePO4) service battery with lead-acid starter battery |
| Weight | 0.12 kg |
| GTIN | 8719076022183 |
Applications
- Motorhomes and campervans with a lithium leisure battery and a vehicle starter battery charged from the alternator.
- Narrowboats and canal boats with a lithium service bank alongside a lead-acid engine start battery.
- Marine vessels requiring BMS-controlled charge isolation to protect a lithium battery bank.
- Off-grid vehicles and expedition builds where alternator charging feeds a lithium battery system.
- Any dual-battery installation where a Victron lithium battery BMS must be able to interrupt the charge circuit.
What Is Included
- 1x Victron Cyrix-Li-charge 12/24V-120A intelligent charge relay
Installation Notes
Installation should be carried out by a qualified electrician or experienced marine/vehicle electrical installer. The Cyrix-Li-charge must be wired in accordance with the Victron installation manual, with correct fusing on both battery connections. The BMS charge disconnect wire must be connected for the lithium protection function to operate. Do not use this relay as a standalone combiner without BMS integration in a lithium system. For marine installations, follow RCD or MCA wiring standards as applicable. Always verify polarity and voltage compatibility before energising the circuit.
Return Policy
xWe offer a 14-day, no-quibble returns or replacement policy because we want you to be totally satisfied with your purchase.
If you are unhappy in any way with your purchase, you can return it for a refund or a replacement, as long as you return it in the same condition as it arrived (original/undamaged packaging and product) and within 30 days of receiving it. We will pay for your return postage on a faulty item as long as you send it using Royal Mail 2nd class recorded delivery (for EU or International Shipments, you have to use our UPS account, we will provide you with a return label)
Please keep in mind the following:
- Items returned within 14 days but not in their original and undamaged packaging will also incur a -15% charge per package.
- If you return an item that doesn't adhere to our returns procedure or doesn't include a returns form, you may be liable for a £10 administration fee
- Individual items from a bundle can't be returned, refunded or exchanged. If you want a refund/credit/exchange for a bundle, all items must be returned to us.
Before you return your item, please make sure that:
- You follow our returns process (outlined below)
- The goods and packaging are undamaged
IMPORTANT: We need to be able to identify an item with your order. We can only do this if you follow our returns process. Please do not send us items back that do not follow this process as they cannot be identified properly and will not be replaced or refunded.
What delivery method do I need to use when returning an item?
You must send the goods back to us via Royal Mail 2nd class recorded delivery. Refunds on faulty items returned are reimbursed within 5 working days.
Can I return just one item from multiple purchases?
Yes. Once you start the returns process you will go to a page that will allow you to choose which items you want to be replaced or refunded.
Returning faulty goods
If your item is faulty, you need to follow the returns policy, where you will be able to state that it’s faulty. The product will then arrive at our warehouse for testing.
If your purchase is not within 14 days
You can still exchange your item for a different product or for credit to use on the Voltacon Solar or Ledison-led-lights.co.uk websites (-15% from the credit amount).
Returns outside of the 14-day period do not qualify for the free returns policy.
Returning an item within the warranty
If you have a warranty and want to return a faulty item, you just need to follow our standard returns process. When we receive your item, we will then check that it’s within warranty and for any faults before arranging a replacement.