I. Introduction
Aircraft batteries serve as a crucial component of an aircraft’s electrical system, serving various purposes and exhibiting unique features that differentiate them from general-purpose batteries.
Differentiation from General-Purpose Batteries:
- Aircraft batteries are specifically designed with a primary focus on minimizing weight. This emphasis on weight reduction is critical because every extra pound of weight affects an aircraft’s performance and fuel efficiency.
These batteries must fulfill a dual function:
- Cranking: Aircraft batteries are responsible for providing the initial burst of electrical power required to start the aircraft’s engines. This “cranking” function is vital for getting the engines up and running.
- Emergency Backup: In addition to cranking power, aircraft battery charger also serve as an emergency backup source of electrical power. This backup power is essential in case the aircraft encounters electrical system failures or other emergencies.
Vulnerabilities
- Lead storage plates are thin and prone to damage if improperly charged.
- Electrolyte chemistry is highly concentrated, with a higher specific gravity.
- Lower charging voltages make aircraft batteries more susceptible to damage from general-purpose chargers.
Cost Considerations
- Aircraft batteries are relatively expensive due to small market sizes.
- Certification, regulatory compliance, and aviation product liability contribute to their costs.
III. Maintenance Charging for Extending Battery Life
Full-Time Maintenance Charging: A Lifesaver
To ensure prolonged battery life, continuous maintenance charging is paramount. Neglecting this crucial practice can lead to premature battery failure and increased costs.
IV. Self-Discharge and Sulfation
Self-Discharge
- All lead-acid batteries gradually self-discharge during storage.
- Self-discharge accelerates with rising temperatures.
- Extended unattended hangar storage creates ideal conditions for battery decline.
Sulfation
- Sulfate crystals form on battery storage plates in a discharged state.
- These crystals hinder electrochemical reactions and weaken battery output.
- Approximately 85% of lead-acid batteries fail prematurely due to sulfation.
V. Solutions for Extending Battery Life
The Key: Full-Time Maintenance Charging
- Aircraft should be connected to maintenance chargers when not in use.
- Precise voltage regulation is vital for extended charging periods.
- Charging voltage must adjust to ambient temperature changes.
VI. Aviation Maintenance or Float Charger
Essential Charger Features
- Aviation-specific charger tailored to aircraft battery characteristics.
- Automatic, continuous operation with condition testing and power failure restart.
- Ambient temperature sensing and continuous voltage regulation.
- Effective sulfate accumulation dissolving for lost battery capacity.
VII. Aircraft Batteries and Their Uses
On Ground
- Batteries serve as a backup power source when external power is unavailable.
- Capable of starting the auxiliary power unit (APU) and energizing essential components.
- APU can further supply power to the entire aircraft’s electrical network.
In Flight
- Aircraft primarily rely on engine-driven generators or the APU generator for power.
- Batteries become the last resort in case of generator failures, providing power to critical components for emergency landing.
VIII. Threats and Mitigation
Potential Threats
- Battery leakage, charging failure, excessive discharge, and faults.
- Short circuits and battery fires.
- Mitigation through proper design, testing, and operational procedures.
- Safer battery materials explored during aircraft certification.
IX. Conclusion
In conclusion, aircraft batteries are indispensable for both ground operations and in-flight emergencies when used within their operational limits. Full-time maintenance charging and smart charger technologies play a pivotal role in preserving these vital energy sources and enhancing safety in the skies.
