Estimating the Time-of-Involvement of Bulk Packed Lithium-Ion Batteries in a Warehouse Storage Fire

A novel experimental approach was developed to evaluate the hazard posed by bulk storage of Li-ion batteries in warehouse scenarios. The flammability characteristics of cartoned small-format Li-ion batteries were evaluated via free-burn fire tests of three-tier-high rack storage arrays. For each test, only the ignition flue area of the array was lined with commodity as a means of reducing the required quantity of Li-ion batteries. Effort was placed on measurement of the fire development and, more importantly, the time of significant battery involvement, a key parameter in the hazard analysis of these fires. This parameter was inferred through diagnostics of the convective gas flow, and corroborated with visual observations and analyses of combustion products. For the tests considered herein, Li-ion batteries are shown to contribute significantly to the severity of the storage fires within 5 minutes of ignition.