Present mitigation required: All cells/batteries must be at 30% or lower state of charge.

May be carried at higher states of charge by exception or exemption with proper mitigation.

A build-up of flammable gases, resulting from thermal runaway of lithium-ion batteries, creates the risk of a catastrophic explosion. Some cargo compartments have built-in fire extinguishers. Heat and smoke generated from battery fires can damage the liners or pressure relief panels. This can cause the extinguishing agent to leak, making it less effective against the threat of fire. Batteries shipped in equipment reduces the likelihood of thermal runaway propagation. 

High temperatures and flammable gases can overwhelm standard and more fire-resistant shipping containers. The high temperatures can melt the polycarbonate material. This allows the fire to spread among other cargo or aircraft systems. If the container remains intact, large quantities of flammable gases can accumulate. This can result in a large fire or explosion. An explosion can cause catastrophic structural or system failure. See video: 5000 Lithium-ion batteries in FRC. See research on flammable gases released: Flammable Gases.

Class C cargo compartments have built-in fire extinguishers. The smoke detection and fire extinguishing systems in the lower cargo compartment can detect and suppress most fires. However, the current suppression systems are not adequate to protect against lithium battery fires. This video shows the threat of bulk shipments of lithium batteries in the lower cargo compartment. The agent suppresses the fire but is not able to cool down the cells. As a result, thermal runaway continues to propagate among cells, generating a large volume of flammable gases that could result in a catastrophic explosion. See research on flammable gases released: Flammable Gases

The smoke generated from battery fires can overwhelm the environmental control systems (ECS). This can allow smoke to enter the cockpit and create a low visibility environment. Keeping smoke out of the cockpit is essential for a safe flight. At a minimum, the pilot must maintain a clear unobstructed view of the flight instruments. This video shows an empty freighter compartment with a 5000 lithium-ion battery fire load. A dense smoke fills the cargo compartment and penetrates the cockpit. A packed cargo compartment would create the same flight risks in less time. Smoke in the cockpit can obscure the pilots’ vision and result in loss of control of the aircraft. See research on flammable gases released: Flammable Gases

Pallets of lithium ion batteries can travel in cargo holds. The pallet cover can melt due to the high temperatures. This can result in shifting cargo during maneuvering. An unbalanced cargo load can cause the loss of control of the aircraft.

Additional Links

• Links to more details of the above-mentioned risks
  • • 2020 Lithium Battery Guidance Document - IATA
    • Battery Fire Mitigation Strategies - FAA
    • Fire Safety Highlights - FAA
    • Flammability Assessment of Bulk Packed, Rechargeable Lithium-Ion Cells in Transport Category Aircraft
    • Lithium Battery Risk Mitigation - IATA

• Accidents on airplanes that carried bulk shipments of batteries
  • • Asiana Flight 991 
    • UPS Flight 1307 
    • UPS Flight 6 
• Hazards 

• Energy 
• Energy Release by Rechargeable Lithium-Ion Batteries in Thermal Runaway  
• Measuring Energy Release of Lithium-ion Battery Failure Using a Bomb Calorimeter  

• • Flammable Gases
    
    • Flammability Assessment of Bulk-Packed, Nonrechargeable Lithium Primary Batteries in Transport Category Aircraft
    • Flammability Limits of Lithium-Ion Battery Thermal Runaway Vent Gas in Air and the Inerting Effects of Halon 1301 
    • Impact of Lithium Battery Vent Gas Ignition on Cargo Compartment Fire Protection 
    • Lithium Battery Thermal Runaway Vent Gas Analysis 
    • Summary of FAA Studies Related to the Hazards Produced by Lithium Cells in Thermal Runaway in Aircraft Cargo Compartments 
    • Thermal Runaway Initiation Methods for Lithium Batteries 
  • Propagation 
    • Fire Hazard Analysis for Various Lithium Batteries 
    • Passive Protection of Lithium Battery Shipments