Batteries, Energy and Thermal Runaway
Lithium-ion and lithium-polymer behaviour, cells, voltage, capacity, temperature, charging, remaining power and containment of thermal runaway.
How to prepare for the CAA GVC
Start with the current certificate and authorisation boundary, work through the five official subjects, then apply the material to mission planning, abnormal procedures and post-flight records with your approved RAE(PC).
Core concepts
Concept 1
A battery combines cells to provide the required voltage and capacity; battery voltage, charging voltage, capacity and available energy are related but not interchangeable.
Exam cue: Check cell balance, condition, temperature, charge state and mission reserve before installation.
Concept 2
Lithium-ion and lithium-polymer batteries have load and charging limits, and temperature can reduce available performance or increase damage and fire risk.
Exam cue: Use only the approved charger, settings, location and supervision procedure.
Concept 3
Thermal runaway in one cell can heat neighbouring cells and propagate, so isolation, containment and the manufacturer or emergency procedure must be applied without unsafe handling.
Exam cue: Respond to swelling, unusual heat, damage, smoke or odour as a battery emergency.
Risk pitfalls and guardrails
Treating displayed charge percentage as guaranteed flight time.
Guardrail: Do not treat a GVC, provider procedure, automation feature or Operational Authorisation maximum as permission to ignore current airspace, aircraft, weather, people or operator-specific conditions.
Charging a hot, cold, damaged or swollen pack without following the approved procedure.
Guardrail: Do not treat a GVC, provider procedure, automation feature or Operational Authorisation maximum as permission to ignore current airspace, aircraft, weather, people or operator-specific conditions.
Handling or reusing a battery after a thermal event because its voltage appears normal.
Guardrail: Do not treat a GVC, provider procedure, automation feature or Operational Authorisation maximum as permission to ignore current airspace, aircraft, weather, people or operator-specific conditions.
Memory anchors
Cells
Cells combine to give the battery's required voltage and capacity.
Capacity
Capacity is commonly expressed in ampere-hours or milliampere-hours, not minutes of guaranteed flight.
Temperature
Cold can reduce available output; excessive heat raises damage and thermal-runaway risk.
Charging Voltage
Charging voltage is not the same as the battery's nominal operating voltage.
Time Limited
After loss of generated power, remaining battery-only operation is time limited.
Thermal Runaway
One failing cell can heat adjacent cells; isolate and contain using the approved emergency procedure.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
What happens to pack voltage when identical cells are connected in series?
What happens to ideal pack capacity when identical cells are connected in parallel?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
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