LITHIUM BATTERY FIRE TESTS Harry Webster FAA William J Hughes Technical Center

BACKGROUND Aircraft Cargo Fire –April 99 (LAX) –Dropped pallet of batteries on ramp caught fire –No external ignition source No current limitation on number of batteries shipped

IS THERE A NEED FOR REGULATION? Develop a test methodology to determine: –Number of batteries or pounds of lithium that poses a threat to aircraft safety –Effect of battery number on duration and intensity of fire –Variation due to battery type –Packaging effects (improved type if needed) –Lithium interaction with Halon 1301

TEST FACILITIES 64 CUBIC FOOT TEST CHAMBER –Measured Halon 1301 concentration –Video port –temperature measurement –heat flux measurement –various heat / fire sources

TEST FACILITES (2) TC-10 CARGO COMPARTMENT –Full Scale Tests –Fire Detection –Halon % initial, 3% suppression –Temperature/agent concentration instrumentation

PRELIMINARY TESTS Single battery tests by Dave Blake –Alcohol fire source –flammable electrolyte venting –High intensity lithium fire –flare type and explosive combustion –some visual indication of interaction between lithium fire and Halon

APPROACH Determine the maximum amount of lithium that can be safely controlled in a cargo compartment fire by the on board suppression system –5%/3% Halon 1301 –increment battery number until no longer controllable

APPROACH (2) Investigate the effect of packaging(if needed) Ignition sources / Fire intensity need for battery ignition Repeat series for distinct battery types Expand testing to include full scale tests (if needed)

PRODUCTS Data to support a rule making regarding air shipping of lithium batteries –maximum number of batteries and/or pounds of lithium –packaging requirements (if needed)

TEST SERIES 64 CUBIC FOOT TEST: –Alcohol Fire Baseline tests: 20.6 square inch fire with 50 ml 1-Propanol 90.7 square inch fire with 220 ml 1-Propanol –CR2 battery increment tests 1, 2, 4, 8, 16, 32, 64 and 128 batteries Packaging effects –Cargo liner integrity tests

Preliminary Test Results CR2 Battery Failure Mode: –When exposed to an alcohol fire: Battery initially vents electrolyte gas, usually at the positive electrode. The electrolyte gas “torches” with a red flame and with some propulsive force. After the electrolyte burns off, the molten lithium then burns explosively, spraying white hot lithium through the vent hole. Unrestrained, the battery can bounce around the test fixture

CR2 Battery Tests Tests were run with 1, 2, 4, 8, 16, 32, 64, and 128 batteries –The ignition of a single battery was sufficient to ignite the adjacent batteries –The peak temperature generated by the battery fires did not go up significantly with the number of batteries. –The duration of the peak temperature increased with the number of batteries

CR2 Battery Tests Peak temperatures ranged from 1100 to 1600 DegF Packaging effects. –32, 64, and 128 batteries were placed in cardboard packaging similar to the shipping boxes –Packaging delayed the ignition of the batteries by seconds

CR2 Battery Tests Packaging effects –The packaging kept the batteries together, heat from the fire fused them together. –Once ignited, the fire propagated through all batteries. Cargo Liner Integrity Tests –Three groups of four batteries were arranged so that the torching electrolyte and spraying molten lithium would directly impinge on liner.

CR2 Battery Tests Cargo Liner Integrity Tests –Thin wall cargo liner The battery fire ignited the resin The torching electrolyte penetrated the liner The molten lithium penetrated the liner –Thick wall cargo liner The liner was able to contain the fire Face of liner charred, Fiberglas exposed, but not penetrated

Future Tests 64 Cubic Foot Box Tests: –Effect of Halon 1301 suppression –Addition primary battery types –Lithium Ion batteries Full Scale Cargo Tests –Validate data from 64 FT3 tests