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35-0L5-1006-08 – Thales Avionics Battery Charge Limiter (BCL)
Available now on the Airparts.aero Marketplace.
The 35-0L5-1006-08 is a sophisticated, flight-critical power management unit designed for the electrical systems of Airbus A320, A330, and A340 series aircraft. Manufactured by Thales Avionics, the Battery Charge Limiter (BCL) acts as an intelligent gatekeeper between the aircraft's DC (Direct Current) Essential Bus and the main onboard batteries. Its primary function is to monitor battery health and regulate the charging process to prevent thermal runaway, overcharging, and premature battery degradation.
Operating as a solid-state controller, the 35-0L5-1006-08 automatically manages the connection of the battery to the DC bus via a high-power contactor. It ensures that the battery is only charged when its voltage is below a specific threshold and disconnects the charging circuit once the battery reaches full capacity or if an internal fault is detected.
Key Features
Automated Charge Monitoring: Continuously monitors battery voltage and charging current, adjusting the "Charge" or "No Charge" state based on pre-programmed logic to optimize battery life.
Thermal Protection: Includes logic to disconnect the battery if high-temperature conditions are sensed, a vital safety feature for Ni-Cd (Nickel-Cadmium) or Lead-Acid battery installations.
Fault Detection & Signaling: Integrated with the aircraft's ECAM (Electronic Centralized Aircraft Monitor), providing real-time status alerts and failure warnings to the flight crew.
Power Distribution Logic: Automatically connects the battery to the DC Essential Bus in the event of a total AC power loss, ensuring that critical standby instruments and fly-by-wire computers remain powered.
Solid-State Reliability: Engineered to withstand the electrical transients and "noisy" environments of wide-body and narrow-body commercial transport aircraft.
Technical Specifications
Part Number: 35-0L5-1006-08
Manufacturer: Thales Avionics
Component Type: Battery Charge Limiter (BCL)
Operating Voltage: 28V DC (Standard Aircraft System)
Weight: Approx. 3.5 lbs (1.6 kg)
Interface: ARINC 429 / Discrete Logic
Certification: TSO-C71 (Airborne Static Electric Power Converters)
Application Group: DC Power (ATA 24)
Aircraft Compatibility
Airbus A320 Family: A318, A319, A320, A321 (CEO and NEO variants).
Airbus A330 / A340: Multi-engine wide-body configurations.
Note: The 35-0L5-1006-08 is a standardized Airbus component. Always verify the part number and "Mod Status" against the aircraft's Illustrated Parts Catalog (IPC) Section 24-31 to ensure compatibility with your specific tail number.
Applications
The 35-0L5-1006-08 is utilized for Emergency Power and Battery Management. Its primary roles include:
Battery Isolation: Preventing the battery from draining into the bus during ground operations with engines off.
Emergency Transition: Facilitating the instantaneous switch to battery power during an APU or Generator failure.
Maintenance Diagnostics: Providing BITE (Built-In Test Equipment) data to ground crews for troubleshooting electrical bus faults.
Why Choose 35-0L5-1006-08?
Choosing the genuine Thales 35-0L5-1006-08 ensures the DC Bus Stability of your aircraft. The BCL is calibrated to distinguish between a "dead" battery and a "shorted" battery. A non-OEM or improperly overhauled unit might attempt to charge a shorted battery, leading to localized heating or smoke in the avionics bay. The Thales unit uses high-precision Current Shunts and logic processors to ensure that the transition from "Charging" to "Standby" occurs within milliseconds of reaching the target voltage.
The 35-0L5-1006-08 operates on the principle of Voltage-Controlled Switching and Current Regulation. The BCL monitors the battery voltage relative to the DC bus voltage V bus. If V < 26.5V (typical Airbus logic), the BCL closes the battery contactor to begin a charging cycle. To prevent the battery from drawing excessive current from the generators, the BCL uses a pulse-width modulation or resistive logic to "limit" the initial current inrush. This prevents the "tripping" of generator control units (GCUs). Once the battery reaches approximately 31V or the charging current drops below a specific value, the BCL opens the contactor, placing the battery in a "Standby" state to protect the internal chemistry from Hydrogen Outgassing.
Note: This is a flight-critical avionics component. Installation must be performed by a certified A&P/AME. Prior to installation, ensure the aircraft batteries are in a healthy state and the DC bus is de-energized. Post-installation, a "Battery Functional Test" via the cockpit overhead panel must be performed to verify BCL contactor engagement and ECAM messaging.
