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RG380E/44L – Concorde Sealed Lead Acid Aircraft Battery (24V, 42Ah)
Available now through the AirParts Aero marketplace.
Overview Section
The Concorde RG380E/44L is a world-class Recombinant Gas (RG), Valve Regulated Lead Acid (VRLA) battery, widely considered the "gold standard" for turbine starting and emergency power. As part of Concorde’s Platinum Series®, the RG380E/44L is engineered for high-duty cycle environments where reliability and high-current discharge are non-negotiable.
The "L" suffix denotes a specific terminal or casing configuration compared to the "K" variant, though it retains the high-energy density and vibration resistance that Concorde is known for. Utilizing proprietary Absorbent Glass Mat (AGM) technology, this battery is completely maintenance-free and eliminates the need for hazardous Ni-Cad electrolyte servicing or flooded battery water replenishment.
Key Features Section
Platinum Series® Technology: Designed with high-purity lead-calcium grids that provide lower internal resistance and higher cranking power than standard lead-acid batteries.
Sealed, Maintenance-Free Design: The recombinant gas technology prevents water loss, meaning the battery never requires the addition of electrolyte or water.
Dual-Purpose Power: Specifically balanced to provide the massive amperage required for turbine "spool-up" while maintaining a deep reserve capacity for emergency avionics power.
Non-Spillable & Aerobatic Proven: The AGM separators fully absorb the electrolyte, allowing the battery to operate in any orientation and withstand extreme G-loads without leaking.
Shock and Vibration Resistance: Built with heavy-duty internal connections and a reinforced polypropylene container, it far exceeds the requirements of MIL-SPEC and DO-160 testing.
Superior Cold Weather Performance: Optimized for low-temperature environments, ensuring reliable engine starts in extreme arctic or high-altitude conditions.
Technical Specifications Section
| Specification | Detail |
| Part Number | RG380E/44L |
| Manufacturer | Concorde Battery Corporation |
| Voltage | 24 Volts |
| Capacity (C1) | 42 Amp-Hours (Nominal) |
| Technology | Sealed VRLA / AGM |
| Weight | Approximately 83 lbs (37.6 kg) |
| Cold Cranking Amps (CCA) | High Discharge (Turbine Starting Grade) |
| Certification | TSO-C173a Approved |
Aircraft Compatibility Section
The RG380E/44L is a primary starting battery for a wide range of corporate and regional turbine aircraft:
Beechcraft King Air Series (90, 200, 300, 350): A popular upgrade from Ni-Cad to reduce maintenance costs.
Cessna Citation Series: Commonly used in the 500/550/560 and 525 series jets.
Bombardier Learjet: Suitable for several models requiring high-amp starting.
Pilatus PC-12: Offers the reliability needed for single-engine turbine operations.
Twin Otter & Caravan: Ideal for rugged utility operators who require maintenance-free reliability in remote areas.
Technical Applications & Safety
Concorde batteries are designed to be "plug-and-play" replacements for Ni-Cad batteries, but they require proper charging system calibration.
Safety Warning: Do not "Deep Cycle" needlessly. While Concorde batteries have excellent recovery, allowing a VRLA battery to sit in a discharged state ($<20V$) for extended periods can cause "sulfation," which permanently reduces the battery's capacity. If the aircraft will be idle for more than 14 days, it is highly recommended to use a Concorde-approved Battery Minder or trickle charger to maintain the plates at a full state of charge.
Technical Engineering Insight
The engineering value of the RG380E/44L lies in its Low Internal Resistance (ESR). During a turbine start, the battery must deliver upwards of $800-1000$ Amps for several seconds. Any internal resistance converts that energy into heat instead of cranking power. Concorde’s specialized grid geometry and AGM compression ensure that the path for electrons is as short and efficient as possible. This results in faster engine acceleration, cooler starts (lower ITT/EGT), and a significantly longer lifespan for the engine's starter-generator.
Installation & Maintenance Addendum
Capacity Testing: Per FAA regulations and Concorde's instructions for continued airworthiness (ICA), this battery must undergo a periodic capacity test (usually every 12 months or 1000 hours) to ensure it still holds at least 80% of its rated capacity.
Terminal Care: Ensure terminals are clean and torqued to the specific inch-pound rating found in the Concorde Component Maintenance Manual (CMM). Over-torquing can damage the lead inserts.
Ventilation: Even though it is sealed, the battery features pressure relief valves.7 Always ensure the aircraft's battery box vent tubes are clear and properly routed to the exterior of the airframe.
