RG380E/44K - Gill Sealed Acid 24 Volt 44 Amp Aircaft VRLA Battery SPA67

RG380E/44K – Gill Sealed VRLA Aircraft Battery (24V, 44Ah)

Available now through the AirParts Aero marketplace.

Overview Section

The Gill RG380E/44K is a high-capacity, Valve Regulated Lead Acid (VRLA) battery designed for heavy-duty starting and emergency power applications in turbine and high-performance piston aircraft.1 This "Sealed" battery utilizes Absorbent Glass Mat (AGM) technology, which immobilizes the electrolyte, making the battery completely non-spillable and maintenance-free.2

The RG (Recombinant Gas) series is Gill’s premier line, engineered to provide high cranking power (CCA) and superior cold-start performance. The 44K designation indicates a robust 44 Amp-Hour capacity, making it a preferred choice for aircraft with high electrical loads or those requiring significant reserve power for emergency flight transitions.

Key Features Section

• VRLA / AGM Technology: Recombines oxygen and hydrogen gases internally to prevent water loss; no more "topping off" with distilled water.3

  
  

  
  

• Non-Spillable Design: Can be installed in any orientation (though upright is standard) and is classified as "non-hazardous" for shipping purposes per ICAO/IATA regulations.4

  
  

  
  

• Exceptional Cranking Power: Optimized for turbine "cool starts," providing high discharge rates to ensure the engine reaches self-sustaining RPM quickly, reducing the risk of a "hot start."

• Superior Capacity Retention: Features low self-discharge rates, allowing the aircraft to sit for longer periods without requiring a trickle charger (though one is always recommended).

• Through-the-Partition Intercell Welds: Reduces internal resistance to maximize power delivery during the critical initial seconds of the engine start sequence.

• Aerospace-Grade Casing: Housed in a heavy-duty, impact-resistant thermal plastic container designed to withstand the vibration and G-loads of flight.

Technical Specifications Section

Aircraft Compatibility Section

The RG380E/44K is a high-demand power source for various mid-to-large business and utility aircraft:

• Beechcraft King Air Series (200, 300, 350): Often used in dual-battery configurations for reliable turbine starting.

• Cessna Citation Series: A popular replacement for older Ni-Cad or flooded lead-acid batteries in 500/550/560 models.

• Pilatus PC-12: Provides the high-reserve capacity required for the PC-12’s advanced avionics and engine start.

• Bombardier Learjet: Compatible with specific Lear 31/35/45 electrical system requirements.

• De Havilland DHC-6 Twin Otter: Reliable starting power for rugged, remote operations.

Technical Applications & Safety

While "Maintenance-Free," VRLA batteries still require periodic Capacity Testing (typically every 12 months) to ensure they can meet the emergency power requirements of the aircraft’s Type Certificate.

Safety Warning: Thermal Management is Key. While VRLA batteries are much more resistant to "thermal runaway" than Ni-Cad batteries, they can still overheat if the aircraft's voltage regulator is set too high. Ensure the charging system is calibrated to the voltage recommended in the Gill service manual (usually 28.2V to 28.5V). Additionally, never jump-start a totally flat RG380E/44K from a high-amperage GPU; the internal heat generated can damage the AGM separators.

Technical Engineering Insight

The engineering value of the RG380E/44K lies in its Recombination Efficiency. In a traditional flooded battery, electrolysis during charging turns water into hydrogen and oxygen gas, which escapes through vents. In the RG380E/44K, the oxygen produced at the positive plate migrates through the AGM pores to the negative plate, where it reacts to reform water. This cycle is nearly 99% efficient. This is critical for high-altitude flight, where the lower atmospheric pressure would otherwise accelerate fluid loss in a vented battery, leading to premature plate exposure and failure.

Installation & Maintenance Addendum

1. Terminal Torque: Use a calibrated torque wrench on the Elcon-style or bolt-on terminals. Loose connections create massive heat during a 600-amp start, which can melt the battery posts.

2. State of Charge: Always check the Open Circuit Voltage (OCV) before installation. A 24V battery reading below 25.5V should be top-charged before being placed into service.

3. Vent Clearance: Even though it is "sealed," the RG380E/44K has safety relief valves. Ensure the battery box vent tubes are clear to prevent the buildup of trace gases in the battery compartment.