Automatic charge relay ML-ACR Lithium with manual control 12 V 500 A

The BLUE SEA ML-ACR Lithium automatic charge relay is an electronic device designed to automatically connect and disconnect two battery banks (typically a starter battery and a house battery) in a boat's electrical system. It is specifically optimized to work with lithium batteries, ensuring proper charging and protection for this advanced battery technology.

Its primary function is to charge the house batteries from the engine alternator while isolating the starter battery to keep it fully charged and ready for engine start. It automatically connects battery banks when one is being charged and disconnects them when charging stops, preventing cross-discharge and optimizing battery lifespan.

This ML-ACR Lithium automatic charge relay is designed to handle a continuous rated current of 500 amperes (500 A). This high capacity makes it suitable for marine electrical systems requiring significant current management, particularly for large service battery banks.

It is specifically designed for lithium batteries (LiFePO4) because these batteries have different charging and protection requirements than traditional lead-acid batteries. The ML-ACR Lithium integrates voltage detection logic and connection/disconnection thresholds tailored to lithium battery characteristics, helping to prevent overcharging or excessive discharging and extend their lifespan.

The relay is equipped with a manual control that allows the user to override the automatic operating mode. This control typically offers several positions:

AUTO: The relay operates automatically according to its internal logic.ON (Connected): The relay forces the connection between the two battery banks, useful for emergency starting or forced charging.OFF (Disconnected): The relay forces the disconnection of the battery banks, completely isolating the circuits.This flexibility ensures adaptable energy management for different situations.

Yes, the ML-ACR automatic charging relay is bidirectional. It allows charging of service batteries from the engine alternator and, if necessary, can also charge the starter battery from a shore charger or solar panels connected to the service bank, ensuring all batteries remain charged.

Benefits include:

Automation: Manages battery charging without manual intervention.
Alternator protection: Prevents alternator damage from improper connection/disconnection.
Battery lifespan optimization: Ensures proper charging and prevents deep discharge.
Manual control: Provides flexibility for emergency or specific situations.
Robust design: Suited for demanding marine environments.
Lithium-specific: Operating logic tailored to LiFePO4 battery characteristics.

Yes, Blue Sea Systems ML-ACR relays are generally equipped with an LED indicator that provides visual information about the relay's operating status, such as whether it is connected, disconnected, or in emergency start mode. This allows for quick verification of its status.

This ML-ACR Lithium automatic charging relay is designed to operate with 12-volt (12 V) DC electrical systems.

Yes, one of the key functions of this relay is to protect the alternator. By intelligently managing the connection and disconnection of batteries, it prevents voltage spikes or overloads that could damage the alternator, especially when connecting deeply discharged batteries.

Blue Sea Systems products, including this ML-ACR relay, are designed to withstand harsh marine environments. They are built with corrosion-resistant materials and are typically sealed to provide protection against moisture, spray, and vibrations, ensuring long-term durability and reliability on the water.

Yes, thanks to its manual override, this relay can be used for emergency starting. By forcing the connection between the house battery and the starter battery (if the latter is flat), it allows the use of the house battery’s power to start the engine. Once the engine is running, the relay can be switched back to automatic mode.

While it can physically be connected to other battery types, this relay is specifically optimized for lithium batteries (LiFePO4). Its voltage thresholds for connection and disconnection are set for these batteries. Using it with lead-acid batteries (AGM, Gel, flooded) may not optimize their charging or protection and is not recommended.

No, this ML-ACR Lithium automatic charge relay is specifically designed for 12-volt (12 V) electrical systems. It is not compatible with 24 V systems and must not be used in such a configuration.

Yes, this relay can connect battery banks of different capacities (for example, a small starter battery and a large service battery bank). The relay manages the current flow between them based on charging needs, without being limited by capacity differences.

Yes, this relay is generally compatible with most standard 12 V marine alternators. It detects the alternator's charging voltage to activate its automatic connection function. However, it is always recommended to ensure your alternator is in good working order and suitable for lithium battery charging.

Yes, this is precisely one of its main applications. The relay is designed to automatically connect and disconnect a starter battery and a service battery, allowing the alternator to charge both banks efficiently and safely while isolating the starter battery when the engine is off.

For installation, it is essential to use battery cables with the appropriate cross-section to handle the 500 A current, robust battery terminals, and basic tools for marine electrical wiring. A good understanding of marine electrical principles is also recommended, or the intervention of a professional. It is crucial to respect the polarities and wiring diagrams provided by the manufacturer.

The relay must be installed in a dry, well-ventilated location that is easily accessible for maintenance and manual operation. It should be as close as possible to the batteries it connects to minimize cable length and voltage drop. Avoid areas subject to extreme temperatures or excessive vibration.

Yes, it is essential to use fuses or circuit breakers of the appropriate size on cables connected to the relay, as close as possible to the battery banks. These protective devices are critical to safeguard the wiring, the relay, and the entire electrical system against short circuits and overcurrents.